volume	12,	no.	19 december	2012 Abstraction and the Origin of General Ideas Stephen Laurence University of Sheffield Eric Margolis University of British Columbia © 2012 Stephen	Laurence	&	Eric	Margolis This work is licensed under a Creative Commons Attribution-NonCommerical-NoDerivatives 3.0 License. <www.philosophersimprint.org/012019/> 1. Introduction1 Given	their	opposition	to	innate	ideas,	philosophers	in	the	empiricist tradition have sought to explain how the rich and multifarious representational capacities that human beings possess derive from experience. A key explanatory strategy in this tradition, tracing back at least as far as John Locke's An Essay Concerning Human Understanding, is to	maintain that the acquisition of	many of these capacities can be accounted for by a process of abstraction. In fact, Locke	himself	claims	in	the	Essay	that	abstraction	is	the	source	of	all general ideas (1690/1975, II, xii, §1).	Although	Berkeley and	Hume were	highly	critical	of	Locke,	abstraction	as	a	source	of	generality	has been	a	lasting	theme	in	empiricist	thought.	Nearly	a	century	after	the publication	of	Locke's	Essay,	for	example,	Thomas	Reid,	in	his	Essays on the Intellectual Powers of Man, claims that "we cannot generalize without	some	degree	of	abstraction..."	(Reid	1785/2002,	p.	365).	And more	than	a	century	later,	Bertrand	Russell	remarks	in	The Problems of Philosophy:	"When	we	see	a	white	patch,	we	are	acquainted,	in	the first instance,	with the particular patch; but by seeing	many	white patches, we easily learn to abstract the whiteness which they all have in common, and in learning to do this	we are learning to be acquainted	with	whiteness"	(Russell	1912,	p.	101). Despite the importance of abstraction as a central empiricist strategy	for	explaining	the	origin	of	general	ideas, it	has	never	been clear exactly how the process of abstraction is supposed to work. There	are	a	number	of	reasons	for	this.	One	is	that	many	philosophers who	have	written	about	abstraction	have	been	more	concerned	with the	role	of	abstraction	in	supporting	a	metaphysical	agenda	than	with the psychological details of the process of abstraction. Interestingly, philosophers	have	appealed	to	abstraction	in	the	service	of	opposing metaphysical	positions. Some (e. g., Locke	and	Reid)	have called	on it as a means for explaining generality in a way that is consistent 1. This	article	was fully	collaborative; the	order	of the	authors'	names is	arbitrary.	We	would	both	like	to	thank	the	referees	for	Philosophers' Imprint.	Eric Margolis	would	also	like	to	thank	Canada's	Social	Sciences	and	Humanities Research	Council	for	supporting	this	research. ImprintPhilosophers' stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 2 – vol.	12,	no.	19	(december	2012) considering	of	a	Man's	self,	or	others,	and	the	ordinary	proceedings	of their	Minds	in	Knowledge..."	(1690/1975,	III,	iii,	§9). Perhaps it is not surprising, then, that we know so little about abstraction. But given the recurring interest in abstraction, and given the importance of general ideas in thought, philosophers clearly need an explicit framework for understanding abstraction that isn't	beholden	to introspection	and	that is	open	to the	findings of	perceptual	and	developmental	psychology	and	related	fields.	Our aim	in	this	paper	is	to	provide	a	general	framework	that	fills	this	gap and to explore some of its philosophical implications. One of our motivations	is	to identify the	extent	to	which	a	process	that	is	broadly like the one invoked by Locke and other philosophers can explain the acquisition of general representations.3 We should note at the outset, though, that	while this	paper takes its inspiration from	early philosophical	discussions	of	abstraction,	our	focus	is	theoretical	rather than	historical.	We	are	primarily	interested	in	the	explanatory	benefits that	can	be	obtained	by	something	akin to the traditional	notion	of abstraction,	not	with	the	historical	controversies	regarding	how	Locke and	other	philosophers	in	the	modern	era	are	best	interpreted.	We'll see	that	there	are	good	reasons	to	abandon	some	of	the	features	that figured	prominently	in	traditional	accounts	of	abstraction	-	including the link between abstraction and anti-nativist views of cognitive development.	Nonetheless,	we	believe that	philosophers like	Locke were	right	to	emphasize	the	significance	of	abstraction	as	a	means	of acquiring general	mental representations. Even if they	were	wrong 3. In	what follows,	we	will	occasionally	make	reference to the	acquisition	of concepts,	where	a	concept	is	understood	as	a	type	of	mental	representation. However, nothing essential turns	on this	way	of thinking about concepts. On	views	that	take	concepts	to	be	a	type	of	abstract	object,	abstraction	may still	be	important	to	the	acquisition	of	general	concepts	by	way	of	mediating access	to	these	abstracta.	On	such	a	view,	our	talk	of	acquiring	concepts	via abstraction should be understood in terms of acquiring general representations	that	have	concepts	as	their	semantic	values. In	any	case,	our	focus in	this	paper	is	on	the	question	of	how	general	mental	representations	are acquired;	our	use	of	the	term	concept	can	be	read	as	stipulatively	referring	to general	mental	representations. with	broadly	nominalistic scruples,	while	others (e. g.,	Russell)	have understood	it	to	be	an	essential	ingredient	for	making	sense	of	realism about	universals. Another reason why the psychological details of the process of abstraction	have	been	so	unclear	is	that	philosophers	have	relied	on introspection	as	the	principal	source	of	information	about	the	process. Conflicting opinions regarding abstraction consequently turn on divergent claims about what introspection uncovers. While Locke takes	it	to	be	evident	that	introspection	shows	that	general	ideas	like man or horse2 are acquired through abstraction, others, including Berkeley	and	Hume, claim that they	don't see this at all	when they look	into	their	own	minds.	But	even	if	everyone	were	to	agree	about the	deliverance	of	introspection,	that	would	still	leave	us	largely	in	the dark	about	the	process.	From	a	contemporary	vantage	point,	it	is	well established that	much of the	mind isn't accessible to introspection and	that	introspective	reports	of	psychological	processes	aren't	always trustworthy.	There	is	little	reason	to	think	that	the	processes	involved in	abstraction	should	be	an	exception. We suspect, however, that the most important reason why the psychological details of the process of abstraction have remained obscure	is	that	its	adherents	have	not	appreciated	the	need	to	provide	a substantive	explanation	of	how	it	works.	As	Chomsky	has	emphasized, this is often the case	when it comes to the	mind. "One	difficulty in the psychological sciences lies in the familiarity of the phenomena with	which they	deal.	A certain intellectual effort is required to see how	such	phenomena	can	pose	serious	problems	or	call	for	intricate explanatory theories. One is inclined to take them for granted as necessary	or	somehow	'natural'"	(Chomsky	2006,	p.	21).	Consider	how Locke	peppers	his	discussion	with	phrases	that	are	meant	to	highlight the	obviousness	of	his	subject	matter.	For	example:	"That	this	is	the way, whereby Men first formed general Ideas,	and general Names to them, I think, is so evident, that there	needs	no	other	proof of it, but the 2. We	take	Locke's	Ideas	to	be	mental	representations	and	will	use	expressions in	small	caps	to	refer	to	mental	representations. stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 3 – vol.	12,	no.	19	(december	2012) only	leave	out	of	the	complex	Idea	they	had	of	Peter	and James, Mary	and	Jane,	that	which	is	peculiar	to	each,	and retain	only	what	is	common	to	them	all.	(III,	iii,	§7) Locke scholars have debated how to interpret Locke's remarks about the nature of abstraction and even whether he has a single account.	This is	understandable,	since	there	is	some	unclarity	about whether Lockean general ideas are formed by retaining the full representations	associated	with	the	particulars	that	an	agent	perceives. To some readers, it sounds like the full representations	are retained and	that	abstraction	involves	attending	to	certain	features	as	opposed to	others.	However,	to	others	readers,	there	is	the	suggestion	that	an abstract idea	may involve the construction	of a new representation, one	that	takes	some	features	from	the	representations	of	experienced particulars	while	omitting	others.4	Regardless	of	what	the	right	story is	about	Locke,	it is	clear	that	he	views	abstraction	as	a	process	that is	grounded	in	perception	and	that	operations	on	the	representations resulting	from	contact	with	particulars	are	the	source	of	the	ability	to represent	far	more	than	the	items	that	were	originally	perceived	-	not just this	white	paper	but	all	white	objects,	not just this	man	but	all human	beings,	and	so	on. But	how	exactly	can	abstraction	be	the	source	of	all	general	ideas? To	see	the	force	of	this	question,	we	need	to	step	back	and	consider more carefully what input gets the process going. If abstraction is to explain the origins of all general representations, what kinds of representations can it draw upon, and how do they depict the particulars that an agent perceives? We will argue that there are four	models	of	the	representational	input	that	are	available	to	Locke but that	none	of these	models	can	provide	a	satisfactory	account	of the origins of all general representations. The result,	we	will argue, 4. The	difference	between	these	two	approaches	is	nicely	summed	up	by	the contrast between J.	L.	Mackie's description of abstraction as selective attention	and	Jonathan	Dancy's	slogan	that	abstraction is subtraction	(Mackie	1976, Dancy	1987). about	significant	details	about	how	the	process	of	abstraction	works, abstraction	does	play	an important role in	explaining the	origins	of general	representations. 2. Some General Representations Are Innate In Book II of the Essay, Locke describes the process of abstraction, claiming that abstraction is the source of all of the mind's general representations.	According	to	Locke,	abstraction	is	the	power	of	mind that	involves	"separating	[Ideas]	from	all	other	Ideas	that	accompany them	in	their	real	existence;	this	is	called	Abstraction.	And	thus	all	its General Ideas are	made" (1690/1975, II, xii, §1). Locke gives several examples that are meant to illustrate the workings of abstraction. Regarding	the	origins	of	the	general	representation	white,	we	are	told: ... the same	Colour being observed to day in Chalk or Snow,	which the	Mind	yesterday received from	Milk, it considers	that	Appearance	alone,	makes	it	representative of	all	of	that	kind;	and	having	given	it	the	name	Whiteness, it	by that	sound	signifies the	same	quality	wheresoever to	be	imagin'd	or	met	with;	and	thus	Universals,	whether Ideas	or	Terms,	are	made.	(II,	xi,	§9) The claim is that a general representation for a simple quality is formed	by (in some	sense) leaving	out specific	details about	where and	when	it	originated,	as	well	as	other	ideas	that	may	have	initially accompanied	it.	Later,	in	Book	III,	Locke	discusses	a	different	kind	of example	-	the	formation	of	a	complex	idea.	He	suggests	that	children may	acquire	man	by	first	attending	to	particular	individuals,	such	as their	nurse	or	mother,	and	later	observing	that	other	things	resemble those	individuals.	This	leads	children	to: ...	frame	an	Idea,	which	they	find	those	many	Particulars do	partake	in;	and	to	that	they	give,	with	others,	the	name Man,	for	Example.	And	thus they come to have a general Name, and	a	general	Idea.	Wherein	they	make	nothing	new,	but stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 4 – vol.	12,	no.	19	(december	2012) that	would	comprise	the	input	to	the	acquisition	process,	and	it	would presumably be the perception of its color that would support the acquisition	of	white.	But	then	the	process	of	acquiring	white	would depend upon prior representations that include, among others, the representation	white.	The	model	is	plainly	circular.	It	ends	up	saying that	white	is	the	product	of	a	process	that	takes	white	as	its	input. E.	J. Lowe has made a related point in a criticism of Lockean abstraction (Lowe 1995, pp. 161–2), but there is an important difference	between	Lowe's criticism	and	our	own.	Lowe	claims that abstraction	can't	get	off the	ground if the	agent	doesn't	have	a	way to single out particulars in perception prior to abstraction taking place,	and	he	claims that this requires	being	able to represent	each particular	under	a	sortal	that	provides	a	principle	of	individuation	for things of the same type. Then the	problem is that abstraction can't account	for	where	these	sortal	representations	come	from,	since	they are	a	necessary	precursor	for	abstraction	to	take	place.	Lowe	gives	the example	of	seeing	an	animal.	He	says	that	you	may	not	have	to	know what	type	of	animal	it	is,	but	you	have	to	at	least	represent	it	under	the sortal	animal	in	order	to	single	it	out	from	other	objects.6 We	agree	with	Lowe	that	general	representations	are	required	to get the	process	of abstraction	going,	but	not for the reason that	he cites. The problem isn't limited to sortal representations and isn't primarily	generated	by	the	need	to	represent	particulars.	Rather,	the problem arises for any of the salient features of a perceived object that,	by	hypothesis,	are	part	of	the	input	to	the	process	of	abstraction. Whether the representations of these features provide principles of individuation	is	irrelevant.	Now	we	ourselves	haven't	yet	argued	that general representations	must	figure in the input to the	process. For the	moment,	it	is	simply	an	immediate	consequence	of	the	first	model that	we	are	considering	that	they	do.	Our	own	argument	for	the	need for	general	representations	will	emerge	through	consideration	of	the 6. Though	it	does	not	affect	our	point,	Lowe	wouldn't	put	things	exactly	as	we do	in	the	text,	since	he	is	agnostic	about	mental	representations	and	prefers to	couch	the	issue	in	terms	of	representational	abilities. is that abstraction cannot plausibly be the source of all general representations	and	that	it	is	highly	unlikely	that	any	learning	process could	be	the	source	of	all	general	representations.	If	an	organism	has any	general	representations	at	all,	then,	in	all	likelihood,	some	of	these must	be	innate. We	should	note	at	the	outset	that	this	argument	is	intended	as	an inference	to	the	best	explanation,	not	a	proof.	We	do	not	claim	that	it is	logically	impossible	for	all	general	representations	to	be	acquired without	there	being	some	innate	general	representations.	Rather,	our point	is	that	non-nativist	models	incur	prohibitive	explanatory	costs. Also, to simplify the discussion, we will suppose that the general representation that we are trying to understand is white and that the experience from	which it is abstracted is the visual perception of	a	snowball	(or	a	number	of	snowballs).	We	can	now	rephrase	the issue	as	identifying	how	the	snowball	is	initially	represented	so	that white	can	be	abstracted	from	the	experience.	There	are	four	potential models	to	consider. Model 1: Individual-representations and feature-representations. The first model	takes	as	input	a	combination	of	individual-representations	(i. e., representations which function like names or demonstratives and represent	individuals	qua	individuals)	and	representations	for	each	of the	salient	features	of	the	experienced	particular.	Thus	the	snowball might	initially	be	represented	with	such	representations	as	that, cold, spherical,	and	solid. This	model	faces	a	number	of	problems,	but	the	most	serious	is	that it simply	presupposes that the	process	of abstraction takes	as input general representations.5	This	clearly	won't	do	if	the	goal	is	for	abstraction to	explain	the	acquisition	of	all	general	representations,	as	the	appeal to	prior	general	representations	will	lead	to	a	regress.	Moreover,	color will	undoubtedly	be	among	the	salient	general	features	of	the	snowball 5. The	representations	of	shape,	temperature,	etc.	in	the	input	might	be	nonconceptual	representations,	as	opposed	to	conceptual	ones.	But	they	would	be general	representations	all	the	same. stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 5 – vol.	12,	no.	19	(december	2012) individual	objects	as	such,	the	agent	is	effectively	representationally cut	off	from	all	the	features	of	the	objects. Suppose,	however,	that	we	overlook	the	question	of	why	different individual-representations are grouped together and simply allow that they are. Then a number of individual-representations could be combined, yielding	a representation like this and this and this (each 'this' referring to one of three different white snowballs). Still, the resulting representation	wouldn't do, since (1) it lacks the representational	breadth	of	white	(white is	projectible,	whereas	the conjoined individual representations only pick out the particulars that	have	been	encountered)	and	(2)	it	fails	to	single	out	the	relevant feature	that	these	objects	have	in	common	(whiteness,	as	opposed	to, for	example,	sphericality,	coldness,	snowballness,	etc.).	It's	one	thing to	represent	a	number	of	perceived	objects	that	happen	to	be	white and	quite	another	to	represent	whiteness	(or	to	represent	white	things in general). No finite conjunction of individual-representations of white	things	would	constitute	a	general	representation	of	whiteness. Model 3: Trope-representations. We are asking what the input to the process of abstraction might look like on the Lockean assumption that abstraction is the source	of all general representations.	A third possibility, which is seen in the	work of Thomas Reid, is that it is particularized properties or abstract individuals, also known as tropes, that the input representations represent as such.7 A trope is property-like	in	that	it	constitutes	a	feature	of	a	particular,	but	unlike 7. Reid	remarks	that	"the	whiteness	of	the	sheet	of	paper	upon	which	I	write cannot	be	the	whiteness	of	another	sheet,	though	both	are	called	white",	and he	goes	on	to	add	that	"the	whiteness	of	this	sheet	is	one	thing,	whiteness another" (Reid 1785/2002,	p. 367). For	Reid, there is	no such thing	as the universal	whiteness. There are	only the individual color tropes that are inherent in	each	piece	of	paper, each snowball, etc. Still, the	appearance	of generality	and	the	prevalence	of	general	terms	in	natural	language	are	both to	be	explained	by	reference	to	"general	conceptions".	Though	Reid's	general conceptions	are	very	different	from	Locke's	general	ideas,	and	Reid	himself was	a	trenchant	critic	of	Lockean	ideas,	our	criticisms	of	the	trope	view	do not	presuppose	that	general	representations	are	akin	to	Lockean	ideas	and apply	equally	to	Reid's	general	conceptions. various options regarding the input and through highlighting the necessity	of	explaining	how	learners	can	selectively	attend	to	features of	stimuli.	But	even	then	there	is	no	reason	to	suppose	with	Lowe	that sortals are required to isolate objects for further attention.	There is good	empirical	evidence for	a	mechanism	of	visual	attention that is able to track objects by focusing on their spatial-temporal features, not their kind-individuating features, and that this mechanism is present	early	in	cognitive	development	(Scholl	2001).	So	while	we'll see that Lowe is right to question	whether abstraction can account for	all	general representations,	his focus	on	sortals is too restrictive. The	fundamental	problem	is just that	the	individual-representationsand-feature-representations	model	assumes that	there	are	features	of	a particular	that	initially	need	to	be	represented	as	such;	whatever	these features	are,	the	representations	of	these	features	cannot	themselves be	acquired	via	abstraction	on	this	model. Model 2: Individual-representations only.	In	order	to	address	the	problem with the	previous	model, one	might suppose instead that	particulars are	initially	represented	only	by	individual-representations	without	any general	representations	coming	into	it	until	abstraction	has	taken	place. We	don't	know	of	any	traditional	empiricists	who	have	proposed a model of this kind, however, and for good reason. Individualrepresentations alone don't provide enough information to get the process of abstraction going. If particulars are represented simply as objects, without representing any of their features, then the input just isn't rich enough.	After all,	with the canonical individualrepresentations	-	demonstratives	-	the whole idea is that they represent their referents directly, conveying no information about what the represented	objects are like. But if all the	mind	has to go on	in	representing	two	white	objects	is	this	and	that,	it	would	have no	basis for	cognitively	grouping	the	two	together,	and	certainly	no basis	for	bringing	them	under	a	specific	general	representation	such	as white.	By	limiting	the	initial	representations	to	representations	of	the stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 6 – vol.	12,	no.	19	(december	2012) a process that appeals to an existing general representation (i. e., similar)	in	explaining	the	acquisition	of	a	new	general	representation is prohibited.	Moreover, a completely general concept of similarity would	be	of	little	use	anyway.	Suppose	that	the	agent	deems	that	the referents	of	white1 and	white2	fall	under	the	fully	general	similar	(in some	respect	or	other).	Since	any	two	objects	are	similar	in	infinitely many	ways (Goodman	1972), this	does	not	bring	us	any	closer to	a general representation	of	white, and it leaves the learner	unable to represent the specific respect in	which these two tropes	are similar. Indeed,	it	seems	that	nothing	short	of	a	general	representation	in	terms of	similar	with	respect	to	whiteness	will	do	the	trick,	since	any	two color	tropes	will	be	color-similar	in	indefinitely	many	respects	as	well (corresponding to indefinitely many ways of partitioning the color space	that	include	both	tropes).	But	if	we	need	to	appeal	to	a	general representation	along	the	lines	of	similar	with	respect	to	whiteness, we	might	as	well	admit	that	the	learner	must	already	have	the	general representation white. We are driven back to the problem we saw earlier.	The	input	to	abstraction	would	presuppose	the	representations whose	acquisition	abstraction	is	supposed	to	explain. There is, however, another option for explaining how different tropes	might	be	deemed	similar	and	consequently	why	the	individualrepresentations for these tropes should be grouped together cognitively. This is that the perceived similarity between these tropes	is	itself	explained	in	terms	of	a	represented	trope	(namely,	the trope	of the similarity between white1	and	white2), so that	all	of the representations	in	play	are	representations	of	tropes	as	such.	In	this case, the agent	would represent the referents	of	white1 and	white2 as	being	related	via	a	relational	similarity-trope	that	is	unique	to	them and that no other individuals can participate in. Let's suppose that the	similarity	in	such	cases	is	picked	out	by	similar1. 8	Consider	now 8. This	is	an	oversimplification,	since	any	two	color	tropes	will	stand	in	indefinitely	many	similarity	relations	(just	as	they	would	have	indefinitely	many features	in	common).	But	we	will	grant	this	simplification	for	the	purposes of	argument. a	universal,	it	can	be	present	only	in	one	particular.	This	is	not	merely because	no	other	particulars	happen	to	have	that	feature	but	because, by its	metaphysical nature, a given trope can	be possessed only by a	single	individual	-	tropes	aren't	multiply	instantiable.	Returning	to the snowball example, the	proposal is that the input to the	process of	abstraction includes	a representation	of the	snowball's	whiteness, where	this	is	taken	to	be	a	trope	that	is	inherent	to	the	snowball;	no other	particular	can	participate	in	this	very	whiteness.	In	other	words, the	model	restricts	the	input	to	representations	of	individuals	(tropes, as	abstract	particulars)	but	offers	the	hope	that	the	agent	is	no	longer cut	off	from	representing	the	features	of	the	particulars	she	perceives (tropes, as particularized properties). Features can be represented without	any	general	representations	being	illicitly	smuggled	into	the foundations	of	the	acquisition	process. Unfortunately, appealing to tropes doesn't help. In representing the	whiteness	of two	white	objects, an	agent	would	have to	deploy two distinct representations, white1 and white2, to represent each whiteness	trope	as	such.	Because	these	representations	are	essentially of individuals (namely, the two tropes), this gives rise to	much the same	sort	of	difficulties	that	arose	for	the	previous	model.	There	is	a question	about	why	these	individuals	are	to	be	grouped	together	and how	representing	them	together	yields	a	fully	general	representation as	opposed	to	one	that	merely	picks	out	the	individuals	that	have	been encountered	thus	far. One	might	think	that	some	headway	can	be	made	on	the	question of why tropes are grouped together by saying that the agent also represents	the	similarity	between	the	tropes.	In	the	end,	this	suggestion doesn't	help,	but	it	turns	out	to	be	somewhat	complicated	to	see	why. This	is	because	there	are	different	ways	in	which	the	similarity	might itself	be	represented. The	simplest	way	would	be	to	use	a	general	concept	of	similarity, one that quantifies over the respects in which similar things are similar	to	one	another.	However,	if	we	are	looking	for	a	process	that would	allow	us	to	explain	the	acquisition	of	all	general	representations, stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 7 – vol.	12,	no.	19	(december	2012) Bertrand Russell uses a related argument in the context of the purely metaphysical dispute about the status of universals. He argues that a nominalistic metaphysics that relies on resemblance between particulars isn't viable, since it would require "that these resemblances	resemble	each	other,	and	thus	at	last	we	shall	be	forced to	admit	resemblance	as	a	universal"	(Russell	1912,	p.	96).	Russell is right that there is	a	need	for	a	higher-order	relation	of	resemblance, but	in	principle	a	nominalist	could	shun	the	universal	resemblance	by appealing	to	an	infinite	hierarchy	of	tropes,	where	the	resemblance	at any	given	level	is	captured	by	a	trope	that	is	unique	to	the	resemblance tropes at the previous level (Campbell 1990).	We aren't saying this is	an	especially	appealing	metaphysics	(see	Daly	1994	for	criticisms), but so far as we can see, trope theorists are free to postulate an infinite hierarchy of similarity or resemblance tropes in this way if they like. In	contrast, the	argument that	bears	on the	psychology	of abstraction	is	much	stronger.	The	reason	is	that	an	infinite	hierarchy of	representations	of	tropes	has	no	psychological	credibility	whatsoever. Finite creatures like ourselves can't actually entertain an infinite number	of representations.	Yet that is exactly	what	we	would	have to	do	to	appreciate	whiteness	in	general	if	the	input	to	abstraction	is restricted	to	representations	of	tropes	as	such.	Once	again,	it	looks	as	if we	need	a	richer	source	of	input	if	we	are	going	to	explain	how	general representations	are	acquired. Model 4: Generality without discrete representations. We have been looking	at	the	various	options	regarding	the	input	to	the	abstraction process,	keeping	in	mind	the	goal	of	making	abstraction	the	source	of all	general	representations.	We	have	ruled	out	a	range	of	approaches that take some combination of representations of individuals as such	and	representations	of	features	as	such	(models	1	and	2),	and also	approaches	that	take	as	input	representations	of	particularized properties (tropes) as such (model 3). These come close to exhausting the	options that	ought to	be	considered.	However,	one further	possibility is that	more	complex	metaphysical	entities than what	happens	when the learner represents	a third	white	object, say, a	white	sheet	of	paper.	The	learner	will	represent	the	paper	as	being white3 (with white3). She	might then come to compare the paper's whiteness	to	the	other	two	objects	and	notice	the	similarity	between the	referents	of	white1	and	white3	and	between	white2	and	white3.	To represent	these	similarities,	she	could	employ	representations	of	the relational tropes involved	-	similar2 and similar3. Now the learner has	three	similarity	representations,	but	how	can	she	recognize	that these	similarity	relations	have	anything	in	common?	If	we	follow	the prescription that perceived similarity requires representing a trope, then	we'd	have	to	say	that, for	each	of	these	pairs, there	is	a	higherlevel similarity-trope representation	of the similarity between these relations (similar4, similar5, similar6), and presumably there	would have	to	be	yet	another	level	representing	the	tropes	that	explain	the similarity	among	these	relations,	and	so	on	(see	figure	1).	A	model	that appeals exclusively to represented tropes ends	up	with a regress in which	each	further	level	of	represented	tropes	fails	to	get	us	any	closer to	a	fully	general	representation	of	whiteness. Figure 1.	Representations	of tropes	of	whiteness can	be compared using similaritytrope representations, but further similaritytrope representations are required to compare	these,	generating	a	representational	regress. stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 8 – vol.	12,	no.	19	(december	2012) have to be 2100 distinct representations that could serve as input to the abstraction process. That's about 500 trillion times more representations than there have been seconds in the history of the universe	(on	the	estimate	that	the	universe	is	20	billion	years	old	or roughly	6.3	x	1017	seconds).	In	our	view,	the	truly	staggering	number	of primitive	representations	at	play	is	enough	to	undermine	a	model	that relies	wholly	on	unstructured	representations. But the problem	with this	model isn't just the sheer number of primitive representations that it would require. The real problem is with how it could account for our ability to acquire white from such representations as this-is-cold-spherical-white without a representational basis for homing in on just the whiteness in the experience. To mentally focus on whiteness itself would seem to require the prior ability to represent whiteness as such, but this amounts to helping ourselves to the general representation white. Once	again, the	account in	question seems to	be circular: it cannot explain	how	the	system	could	derive	a	representation	of	white	from the	input	without	presupposing	that	the	system	already	has	the	ability to	represent	whiteness. It is easy to suppose that abstraction explains the origins of all general	representations	if	you	don't	think	through	the	psychological details.	But	what	the	failure	of	these	four	models	shows	is	that	there is a substantial burden for theorists who want to maintain this position.	The	principal	options	for	getting	the	process	of	abstraction going	are	all	problematic.	They	either	presuppose	a	certain	amount of general representation or are unable to support the acquisition of the target general representation. Of course, there is always the possibility	that	there	might	be	some	further	model	of	how	abstraction gets started that we have not considered, one that can (somehow) account for the origins of all general representations. For example, it	might	be	said	that	abstraction	isn't	a	representational	process	and hence	that	the	input	needn't	include	any	representations	at	all,	much less general ones. All that is required are causal interactions with individuals and features are represented in the input	-	something akin to events or states of affairs. In this case, the initial representations forming	the input to the	abstraction	process	might be	unstructured	representations	that	manage	to	pick	out	these	more complex	entities	without	any	components	representing	the	objects, properties, or tropes that are present in the event. For example, a snowball	might be represented as being cold, spherical, and white but	without	separate	representations	corresponding	to	each	of	these features.	The	snowball's	being	cold,	spherical,	and	white	would	be represented by a single unstructured representation (this-is-coldspherical-white), not by a structured representation composed of distinct representations capable	of independently representing the object	and	these	several	features	(this,	cold,	spherical,	and	white). In this way, white	wouldn't have to be a precursor to abstraction, nor would there have to be prior access to any other general representations	corresponding	to	a	particular's	features. Once again, however, psychological considerations need to be taken into account. And from a psychological perspective, such a model is not at all promising. One important feature of our systems	of representation is	productivity.	The	mind	can	represent	an indefinite number of distinct combinations of features, for which the best explanation is that discrete representations are combined and recombined in accordance with a compositional semantics. However,	the	model	under	consideration	(generality	without	discrete representations)	is	built	on	the	assumption	that	the	representational system	doesn't	have	the	compositional	structure	that	this	explanation requires.	Instead,	for	each	new	combination	of	features	attributed	to an	object, there	would	have	to	be	a	corresponding	new	and	unique primitive representation. Unfortunately, this would require us to possess	an	astronomical	number	of	primitive	representations	to	serve as input	to	the	process	of	abstraction.	Since	for	any	n features	there are	2n	possible	combinations	of these features, this	means that	with only a single object and 100 basic features and their combinations to represent	-	an absurdly conservative assumption	-	there would stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 9 – vol.	12,	no.	19	(december	2012) First consider Berkeley's criticisms, which primarily focus on Locke's	construal	of	ideas	as	mental	images	and	the	view	that	these images	can	represent	only	what	they	resemble	(Berkeley	1710/1975). Among	other	things,	Berkeley	points	out	that	images	are	determinate in ways that bar them from achieving the generality that Locke requires. For example, you can't have an image of a generic man that	represents	men	in	general.	To	be	recognizable	as	an	image	of	a man,	it	would	have	to	include	specific	details	(e. g.,	size,	shape,	color) that	might be true	of some	men	but not of others.	While this	may be a trenchant criticism	of	Locke, given the	Lockean	view	of ideas, proponents of abstraction needn't be committed to the view that ideas	are	mental	images	or	to	the	resemblance	theory	of	content,	not even	for	the	representations	that	subserve	perceptual	processes.	So, for	contemporary	theorists, these	criticisms	don't	really identify the fundamental	problems	with	abstraction. Now consider Berkeley's own theory of the origins of general representations. According to Berkeley, a general representation arises	as	an	image	becomes	used	to	represent	a	range	of	particulars that are similar to the	one that the image initially	picks	out. In this way, a representation that is initially	particular can	become	general. Berkeley gives the analogy of a drawing of a line in a geometrical proof.	Although	the	line	may	be	one	inch	long,	it	comes	to	represent all	lines,	not	just	one-inch	lines,	because	the	proof	doesn't	turn	on	its particular	length: And, as that particular line becomes general by being made	a	sign,	so	the	name	line,	which	taken	absolutely	is particular,	by	being	a	sign, is	made	general.	And	as the former	owes	its	generality,	not	to	its	being	the	sign	of	an abstract	or	general	line,	but	of	all	particular	right	lines	that may	possibly	exist,	so	the	latter	must	be	thought	to	derive its generality from the same	cause,	namely, the	various particular lines	which	it indifferently	denotes.	(Berkeley 1710/1975,	introduction,	§12) property instances. We grant that models of this sort aren't ruled out	by anything	we	have said.	But they are	decidedly	unattractive.9 They effectively postulate mysterious neurological processes that inexplicably	yield	content-appropriate	general	representations	simply on	the	basis	of	causal	contact	with	the	world.	Indeed,	without	a	welldeveloped	account	of	how	the	process	works,	it	is	hard	to	see	how	a non-representational	model	of	this	kind	is	substantially	different	from a	model that takes certain	general representations to	be innate	and triggered	by	appropriate	causal	interactions.	In	any	case,	as	we	noted, we intend	our	argument to	be	an inference to the	best explanation. The burden is on theorists who think that abstraction can account for	the	acquisition	of	all	general	representations	to	produce	a	model of	abstraction	that	can	plausibly	meet	this	desideratum.	Absent	such an	account,	we	conclude	on	grounds	of	explanatory	plausibility	that abstraction	cannot	explain the	origins	of	all	general representations and	that	some	general	representations	are	innate. Locke	was	not	alone	in	failing	to	appreciate	the	sorts	of	difficulties we	have	been	pointing	to	and	the	need	to	attend	to	the	psychological question	of	how	abstraction	works.	Locke's	account	of	abstraction	was famously	rejected	by	Berkeley	and	by	Hume	as	well	(largely	based	on Berkeley's vigorous criticism	of the account). From	a contemporary perspective,	however,	Berkeley's	criticisms	don't	cut	very	deep,	since an	advocate	of	abstraction	can	drop	the	assumptions	that	Berkeley's criticisms turn on. And despite their spirited rejection of Lockean abstraction,	the	alternatives	to	abstraction	embraced	by	Berkeley	and Hume	face	much	the	same	sorts	of	problems	regarding	the	input	to the	process	that	we	have	been	arguing	Locke's	account	faces. 9. Much	the	same	might	be	said	for	an	Aristotelian	model	where	sensible	forms are taken to be literally transmitted from an object, through a perceiver's sense	organs,	into	the	mind.	Adams	(1975)	succinctly	describes	such	a	view as	follows:	"Perception	was	interpreted	as	a	transaction	in	which	a	form	(the sensible form) is transmitted from	the	perceived	object to the	perceiver.	... There	is	something	(the	sensible	form)	which	literally	comes	into	the	mind from the	object.	This theory	of perception is the	basis for the	Aristotelian empiricist	answer	to	the	question,	how	we	get	our	ideas"	(p.	73). stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 10 – vol.	12,	no.	19	(december	2012) general	representation	white	and	hence	reintroduce	the	problem	of circularity.11 And general representations aren't really an option for Berkeley	anyway,	since	the	whole	point	of	his	treatment	of	generality is	that	it	is	supposed	to	do	away	with	fully	abstract	general	ideas. The	situation	for	Berkeley	isn't	all	that	different	from	the	situation for	Locke,	and	it's	the	same	for	any	theory	of	abstraction,	or	substitute process, once the need to specify the input is taken seriously. At least	some	general representations	have to	be	available to	get	such a process going. Some general representations have to be innate. The moral	we	draw from	these reflections is that the	hope	of	providing a comprehensive theory of the origins of general representations should	be	abandoned.	Still,	a	process	worthy	of	the	name	abstraction might explain the origins of many general representations and thus be an important part of how	human representational systems develop.	In	particular,	the	process	of	abstraction	might	profitably	be seen as starting with relatively specific general representations as input	(e. g.,	a	representation	for	a	given	shade	of	color	or	a	narrowly circumscribed shape) and delivering another type of general representation	as	output	(e. g.,	broader	color	or	shape	representations, such	as	red	or	triangular).	The	input	representations	would	capture the	particularity	of	the	represented	qualities	in	experience	-	what	is often called the fine-grainedness of perceptual experience. But the output representations	would	be	comparatively	more general in that they	"abstract"	from	the	particularities	of	the	individually	experienced colors, shapes, and so	on.	This is the idea that	we	plan to	develop in the sections to come. It is a major departure from Locke and from other traditional accounts, but as	we've seen, these accounts face	insuperable	difficulties	in	explaining	how	a	theory	of	cognitive development	can	get	by	with	anything	less. 11. Hume's	account	of	generality	is	no	better.	Hume	presupposes	that	people	can recognize	that	different	objects	resemble	one	another.	It's	on	the	basis	of	the resemblance that the	corresponding	particular ideas	become	associated	by a	common	word,	such	as	'triangle'.	But	Hume	doesn't	consider	the	question of	how	the	resemblance	is	registered	psychologically.	He	too	would	confront the	same	set	of	problematic	options. Hume	described	Berkeley's	treatment	of	general	representation	as	"one of	the	greatest	and	most	valuable	discoveries	that	have	been	made	of late	years	in	the	republic	of	letters..."	(1739/1978,	I,	i,	§7).10	But	despite this	high	praise,	it's	hard	to	see	why	Berkeley's	account	is	an	improvement	over	Locke's.	Basically,	we	are	told	that	an	image	achieves	generality	because	it	is	used	as	a	general	representation.	An	agent	starts	out with	an	image	of	a	particular	but	then	enlists	it	to	reason	about	other things	by	ignoring	irrelevant	aspects	of	the	image	and	focusing	on	just the	relevant	ones.	The	problem	with	this	account	becomes	apparent when	we	ask	how	the	mind	manages	to	achieve	this	feat. Suppose the image is	of	a specific snowball that	a child	has just seen and that she ignores the depicted shape and texture, among other	things,	in	the	service	of	thinking	about	white	things	in	general. To	do	this,	she	needs	to	selectively	attend	to	the	color	in	the	image.	Yet Berkeley tells	us	nothing	about	how	he	proposes to	account for the ability	to	selectively	attend	to	certain	aspects	of	an	image	while	ignoring others.	In	order	to	psychologically	focus	one's	attention	on	whiteness, one	must, in	effect,	represent	whiteness.	But in	order	to	do	this, the options are essentially those	we considered above for the Lockean account.	Representing	only	particulars,	whether	concrete	particulars or	tropes,	doesn't	allow	one	to	attend	to	whiteness	as	such.	Employing a	general	representation	of	whiteness	would,	of	course,	allow	one	to attend to	whiteness, but that	would require	prior possession	of the 10.	Hume's	own	treatment	of	general	ideas	has	a	strong	affinity	with	Berkeley's, though	the	differences	between	them	are	worth	noting.	Hume	doesn't	follow Berkeley	in	claiming	that	we	simply	attend	to	relevant	aspects	of	an	idea	and ignore	others.	He	says,	instead,	that	as	we	notice	the	resemblance	between different	objects,	we	give them the	same	name,	and then later	uses	of the word	call	up	related	ideas.	For	example,	the	word	'triangle'	may	initially	bring to	mind	an	isosceles	triangle,	but,	because	of	the	association	with	other	triangles, it	may	also	bring	to	mind	ideas	of	equilaterals.	Reasoning	about	triangles	in	general	would	then	amount	to	reasoning	with	an	idea	of	a	particular (say,	just	one	isosceles	triangle)	and	for	this	to	be	accompanied	by	much	the same	reasoning	with	other	related	ideas	(other	isosceles	triangles,	equilaterals,	etc).	In	other	words,	you	start	with	an	image	of	an	individual	and	consider the situation	with respect to	other images	of	other individuals that	bear a resemblance	to	the	first	image. stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 11 – vol.	12,	no.	19	(december	2012) The second component of	Quine's account is a similarity	metric. Quine assumes that the fine-grained discriminatory capacities are innately ordered in terms of similarity (an innate "spacing of qualities"), which he interprets behavioristically. "A standard of similarity	is	in	some	sense	innate.	This	point	is	not	against	empiricism; it	is	a	commonplace	of	behavioral	psychology"	(1969,	p.	123).	Quine's innate similarity metric incorporates a further element of innate generality,	but	it	also	facilitates	learning,	allowing	the	account	to	avoid the	difficulties that earlier empiricist accounts	of abstraction	had in capturing	the	similarity	in	the	input	without	general	representations. The third and	final component of	Quine's account is a selection process. Quine assumes that learners engage in hypothesis testing, where	overt	behaviors	(e. g.,	calling	a	color	sample	'white')	are	selected through positive and negative feedback in accordance with the principles	of	conditioning.	The	selection	process	operates	in	tandem with the innate quality space to isolate a region within that space corresponding to	a	conventional term	(e. g., the	white region	within the	innate	similarity	space).	In	this	way,	the	innate	similarity	space	can come	to	be	partitioned	in	culture-specific	ways.13 The structural features of Quine's basic account	-	innate finegrained	generality,	an	innate	similarity	space,	and	a	selection	process to	isolate	regions	within	that	similarity	space	-	provide	the	foundation we	have	been	looking	for	to	develop	a	workable	theory	of	abstraction. However,	the	details	of	Quine's	account	are	problematic	in	various	ways. The	most	serious	difficulties	stem	from	Quine's	behaviorism.	Consider his	explanation	of	the	innate	similarity	space.	Quine's	account	of	what it	is	to	have	an	innate	similarity	space	is	essentially	that	we	are	innately disposed	to	respond	to	certain	stimuli	in	a	similar	manner.	"A	response to	a	red	circle,	if	it	is	rewarded,	will	be	elicited	again	by	a	pink	ellipse more	readily	than	by	a	blue	triangle"	(1969,	p.	123).	This	explanation, 13. Quine	also	envisions	more radical	changes to the	similarity	space through further	language	learning,	formal	education,	and	the	impact	of	science.	One way	to	think	about	some	of	these	more	radical	changes	is	that	they	alter	the character	of	the	similarity	space	by,	for	example,	introducing	new	dimensions. 3. A Neo-Quinean Framework In this section, we present a general framework for understanding abstraction.	As	will	become	clear,	we	think	that	there	is	a	large	family of	related	acquisition	models	that	share	important	similarities	and	are equally deserving of the label abstraction. Since what is interesting from	a	philosophical	point	of	view	are	the	contours	of	the	framework rather than the details of any particular model, our aim	will be to sketch the	broad	outlines	of the	general framework.	We	take	as	our starting point W.V.O. Quine's treatment of learning in his paper "Natural	Kinds"	(Quine	1969).	While	Quine's	account	faces	significant difficulties,	it	can	be	adapted	and	expanded	in	various	ways	to	provide a	promising	basis	for	understanding	abstraction.12	The	resulting	neoQuinean	framework	makes	it	possible	to	explain	how	abstraction	can account	for	the	origins	of	many	general	representations	without	falling prey to the	difficulties that	we	presented for traditional accounts	of abstraction	in	section	2. Quine's	discussion	is	couched	in	terms	of	an	account	of	word	learning. His	account	has	three	main	components.	First,	Quine	assumes	that	the learner	can	innately	discriminate	a	range	of	fine-grained	properties	in the	learning	domain,	for	example,	different	shades	of	color	in	learning color	words	like	'white'	and	'green'.	These	fine-grained	discriminatory capacities	provide	the	input	to	the	process	of	abstraction.	By	building generality	(albeit	fine-grained	generality)	in	from	the	outset	in	the	form of general capacities for discriminating shades of color,	Quine does limit the	scope	of	abstraction.	He	doesn't take	abstraction	to	explain the origin of all general discriminatory capacities. Nonetheless, for Quine,	abstraction	can	explain	how	a	general	word	like	'white'	could be learned	on the	basis	of the	fine-grained	discriminatory	capacities associated	with	particular	shades	of	color. 12. We	should	note	that	Quine	doesn't	describe	himself	as	offering	a	theory	of abstraction.	Nonetheless,	we	will	discuss	Quine	in	these	terms,	since	we	take the	learning	process	that	Quine	describes	to	be	a	good	starting	point	for	understanding	abstraction. stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 12 – vol.	12,	no.	19	(december	2012) Another	aspect	of	Quine's	account	that	should	be	addressed	is	the character	of	the	selection	process.	Quine	narrowly	focuses	on	a	single type	of	selection	process	(hypothesis	testing	driven	by	conditioning). Though a representational version of this suggestion can account for the acquisition of general perceptual representations, there are numerous possibilities for how a selection process	might function, and	the	neo-Quinean	framework	should	be	taken	to	encompass	the full	range	of	such	possibilities.	Not	all	models	will	involve	hypothesis testing, and among those that do, there will be differences in the assumptions	they	make.	The	processes	involved	in	isolating	a	region in the innate	quality	space	can	range from	relatively	unconstrained processes (e. g., summation of positive instances, or hypothesizing simple regularly shaped regions containing positive instances and excluding negative instances) to highly constrained processes (e. g., where hypotheses are drawn from a highly circumscribed set or where	the	hypothesis	space	evolves	in	an	innately	specified	manner). We	will	offer	examples	along	these	lines	below.	The	important	point for	present	purposes is that a	wide	variety	of	options are available for the selection process, each of	which, in its own	way, isolates a region of the innate quality space in response to the fine-grained representations	that	are	taken	as	input. There are also a	number	of other important sources	of potential variation that Quine himself does not discuss but which ought to be included in the neo-Quinean framework. For example, the finegrained representations that form the basis of abstraction needn't always	be	innate.	In	some	cases,	they	might	be	learned.	Likewise,	the innate quality space might not be developmentally fixed. The size or	dimensions	of this	space	might	be	altered.	Relational	parameters within a quality space might also be altered, or new relations superimposed	onto the space.	There could	also	be	multiple	distinct quality	spaces	and	quality	spaces that	stand in	different relations	of psychological	accessibility	to	one	another.	Taken	together,	these	and the	previously	mentioned	sources	of	variation	introduce	considerable however,	is	little	more	than	a	restatement	of	the	phenomenon	to	be explained.	It	is	no	better	than	saying	that	we	tend	to	respond	to	certain stimuli	similarly	(explanandum)	because	we	are	innately	disposed	to respond	to	those	stimuli	similarly	(explanans).	True	enough,	but	what we	need	to	know	is	why	people	have	the	same	response	to	the	stimuli. This	requires,	at	the	very	least,	the	outlines	of	a	synchronic	mechanism. For this reason, a better account would be one that explains the innate	sense	of	similarity	in	terms	of	an	innate	computational	process operating	over	an	innate	class	of	fine-grained	representations,	where features	of	the	representations	and	the	computational	process	result in representations being ordered so as to produce the similarity effects. Many computational-representational systems are possible here,	and	so	the	details	are	best	left	to	empirical	psychology.	But	we will	assume	that	some	such	account	of	similarity	is	the	right	way	to proceed,	as	an	account that	sticks	purely to	behavioral	dispositions isn't	substantive.	This	is	the	first	step	in	developing	the	neo-Quinean framework	for	understanding	abstraction.	And	once	a	computationalrepresentational	system	is	used	to	explain	the	similarity	space,	it's	only natural	to	adopt	representational	versions	of	the	other	components	of Quine's	account	-	the	fine-grained	discriminatory	capacities	and	the selection	process.	So	our	neo-Quinean framework	will	also include innate fine-grained representations and a selection process that is a	computational	process	-	one	that	operates	over	a	quality	space	of representational	states,	not	a	field	of	behavioral	dispositions.14 14. Without	a	representational	account	of	the	selection	process,	we	would	need an	explanation	of	why	reinforcement	has	its	effects	on	overt	behavior,	and	we would	face	difficulties	arising	from	the	fact	that	the	principles	of	conditioning don't	apply	to	many	instances	of	learning,	including	word	learning	(Chomsky 1959).	Citing	only	external factors	(the impingement	of	stimuli, the imposition	of	rewards,	etc.)	is	inadequate,	since	these	clearly	don't	have	the	same effects	on	every	physical	system.	There	has	to	be	something	about	the	intrinsic	character	of the	learning	system	that	explains	why	conditioning	shapes its	responses.	The	best	account	that	psychology	has	to	offer	is	that,	in	many cases,	the	mechanism	is	deeply	cognitive.	It's	because	of	the	way	that	the	contingencies	of	rewards	and	punishments	are	represented	that	the	principles	of conditioning	have	any	purchase	on	changes	in	behavioral	regularities	(Gallistel	1990;	Gallistel	&	Gibbon	2002). stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 13 – vol.	12,	no.	19	(december	2012) This is just one example, but notice that such a model avoids the	difficulties that	we raised in the	previous section for	Locke	and others,	and	does	so	specifically	by	abandoning	the	Lockean	ambition of trying to explain the origins of all general representations via abstraction. Instead, the model works by supposing that some general representations are innate (e. g., the fine-grained but still general representations of particular shades of white). Abstraction, according	to	the	neo-Quinean	framework,	can't	account	for	all	general representations, but that is of no matter, since no framework can account for all general representations. What this new framework does do, however, is very	much in the spirit of traditional theories of	abstraction,	in	that	it	explains	how	general	representations	can	be learned	on	the	basis	of	fine-grained	perceptual	experience. 4. Implications of the Neo-Quinean Framework We've sketched the general outlines of a workable framework for understanding	abstraction,	but	many	questions	remain	regarding	how the framework	should	be	developed	and	regarding the implications it has for philosophical theories of the mind. In this section, we make some programmatic suggestions.	We offer these in the spirit of	an initial	exploration	of	a	poorly	understood	area that is ripe for philosophical	attention.	But	even	at	this	early	stage	of	inquiry,	we	think there are some important and perhaps surprising conclusions that can	be	drawn.	We	organize	our	remarks	around	three	general	issues: (1) the	empiricism-nativism	debate, (2) the	output	of the	process	of abstraction,	and	(3)	human	uniqueness. (1) Abstraction and the Empiricism-Nativism Debate Abstraction has historically been seen as a distinctively empiricist acquisition process. However, we will argue that there is nothing about abstraction per se that limits it to an empiricist psychology; abstraction	is	equally	compatible	with	nativist	views	of	the	mind.	To see	why,	we	need	to	step	back	and	consider	the	characteristic	features of	nativism	and	empiricism. flexibility	within the neo-Quinean framework.15	While	we	won't be able to systematically explore all these different possibilities, some will	be	discussed	below. In	sum,	the	neo-Quinean	framework	that	we	are	proposing	takes the following form:	Abstraction is a computational-representational learning process that operates over a quality space of fine-grained general representations that are ordered by a similarity metric. Abstraction involves a selection	process that isolates regions of the quality	space.	The	similarity	metric	needn't	be	simple.	In	fact,	it	might be quite complex and	multifaceted. Likewise, the selection process can	take	many	different	forms.	But	one	thing	that	all	variations	on	this basic	model	have	in	common	is	that,	by	building	in	enough	structure right from the outset (some general representations and a suitable similarity	metric),	the	criticisms	that	were	so	damaging	to	traditional theories	of	abstraction	are	avoided. If we return to the example of the general representation white, there	are	numerous	alternative	models	for	how	such	a	representation might be acquired in the neo-Quinean framework. One possibility, just	to	get	the	feel	of	the	framework,	would	be	a	model	much	like	the computational-representational	analog	of	Quine's	own	account	of	color words.	In	this	case,	a	learner	comes	equipped	for	the	task	with	general representations	for	different	shades	of	white	(among	other	colors),	as well	as	an	innate	similarity	metric	that	organizes	her	color	space.	Then, upon	encountering	different	instances	of	white	things	(snowballs,	paper, milk,	etc.),	she	would	represent	those	particular	shades	and,	through a	process	of	positive	and	negative	feedback,	develop	a	representation that	incorporates	all	of	the	shades	that	received	a	positive	signal	and none	of	the	shades	that	that	received	a	negative	signal. 15. Also	open to investigation is the	class	of representations that	might	be	acquired	by	such	a	process.	This	is	likely	to	include	standard	perceptual	representations	(e. g.,	representations	for	colors,	textures,	and	odors).	But	it	might also include representations involved in bodily sensations (pleasure, pain, heat, etc.) and representations of cross-modal and amodal categories (e. g., shape	and	spatial	relations),	among	others. stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 14 – vol.	12,	no.	19	(december	2012) regarding the disagreement between empiricists and nativists, we return	to	the	case	of	color. Currently, there is a lively debate regarding the extent to	which the	acquisition	of	general	color	representations	-	concepts	like	white, blue,	and	green	-	is	innately	constrained.	Some	researchers	view	the learning	of	color	categories	in	strongly	empiricist	terms.	For	example, in	a	recent	review	of	the	literature	on	color	categorization,	Regier	& Kay	(2009)	provide	a	description	of	a	view	that	should	sound	familiar: Debi	Roberson and colleagues	... concluded that there are	no	universal	foci,	that	categories	therefore	cannot	be organized around them, and that ''color categories are formed	from	boundary	demarcation	based	predominantly on	language''	...	subject	to	the	constraint	of	'grouping	by similarity':	namely,	that	categories	must	form	contiguous regions	of	color	space.	The	implication	is	that	apart	from that rather loose constraint, category boundaries are determined exclusively by local linguistic convention. (Regier	&	Kay	2009,	p.	442) Put in these terms, Roberson et al.'s position bears a striking resemblance	to	Quine's	(minus	the	behaviorism).	In	support	of	their view,	Roberson	et	al.	point to	cross-cultural	evidence	demonstrating significant variation in color representations. For example, in an important	study,	Davidoff,	Davies,	&	Roberson	(1999)	report	that	the Berinmo	of	Papua	New	Guinea	use	five	basic	color	terms	that	crosscut the basic color terms in English; one Berinmo term covers both yellow (i. e.,	what's called 'yellow' in	English)	and	numerous shades that	English	speakers	think	of	as	green.	On	Roberson	et	al.'s	account, color representations are learned by identifying different culturally salient	regions	within	a	common	initial	similarity	space.	Since	there are only weak internal constraints on the learning process, color representations	will	vary	significantly	cross-culturally. Empiricists	and	nativists	disagree	about	the	way	that	psychological traits	(psychological	faculties,	states,	dispositions,	etc.)	are	acquired.16 Empiricists	maintain that	most psychological traits are acquired on the	basis	of	a	small	number	of	general-purpose	psychological	systems, while nativists maintain that numerous specialized systems are needed	as	well.	Although	commentators	sometimes	lose	sight	of	the point, both nativists and empiricists appeal to innate psychological traits	in	accounting	for	the	acquisition	of	further	psychological	traits. For example, empiricists who are opposed to innate knowledge nonetheless	suppose	that	basic	psychological	faculties	for	perception and	memory are innate.	Another common	misunderstanding is the supposition	that	empiricists	are	alone	in	giving	a	large	role	to	learning. But nativists aren't opposed to learning. They just disagree with empiricists about how learning takes place and about the systems involved. Empiricists only invoke general-purpose learning systems (e. g.,	principles	of	association),	while	nativists	also	invoke	specialized learning	systems	(e. g.,	an	innate	language-acquisition	device). Far	more	could	be	said	about	the	empiricism-nativism	dispute,	but even	with	this	brief	outline,	it	ought	to	be	clear	that	abstraction	isn't intrinsically	empiricist;	nativist	versions	of	abstraction	are	also	possible. Whether	a	given	occurrence	of	abstraction	should	count	as	empiricist or	nativist	depends	on	how	the	details	are	filled	in.	The	crucial	factors have to	do	with the	character	of the innate	similarity	space	and the types of selection processes that are invoked. For instance, where the selection process is domain-general and subject to few if any innate	constraints,	the	result	will	be	an	empiricist	model.	But	where it	is	domain-specific	and	subject	to	significant	innate	constraints,	the result	will	be	a	nativist	model.	To	illustrate	that	abstraction	is	neutral 16. Historically, concerns about the nature and origins of psychological traits were often conflated with epistemological questions about justification (Cowie	1999).	From	a	contemporary	perspective,	however,	it	is	clear	that	justification	is	one	thing	and	psychology	another.	In	principle,	a	belief	that	requires	empirical	justification	could	be	innate	(e. g.,	the	belief	that	spiders	are dangerous),	while	a	belief	that	is	justified	a	priori	might	not	be	(e. g.,	the	belief that	arithmetic	is	incomplete). stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 15 – vol.	12,	no.	19	(december	2012) colors?	Moreover,	Regier	et	al.	also found	that the	best	examples	of colors across these languages	were	more closely clustered than the center	points	of	the	color	fields	associated	with	each	language's	color terms. This suggests that the best examples are not simply derived from the color fields associated with the terms but rather that the best	examples	are	primary	and	the	color	fields	form	around	them.	A natural	model	that	takes	account	of	this	fact	would	be	to	have	innate focal	colors	around	which	color	fields	are	built	through	a	process	of learning.	Or	another	possibility	is	to	have	innate focal color fields,	where the	best	examples	of	colors	must	lie	within	these	fields	but	the	precise locations	are	open	to	linguistic	influence	and	consequently	subject	to cross-cultural	variation. Our	purpose	here	is	not	to	settle	the	issue	of	whether	a	nativist	or	an empiricist	model	provides	the	best	model	of	color	concept	acquisition. Rather, the illustrations are intended to show that, despite the historical affiliation between abstraction and empiricist approaches to representational-conceptual	development, there is	nothing in the process	of	abstraction	that	exclusively	ties	it	to	an	empiricist	psychology. Empiricists	and	nativists	alike	can	help	themselves	to	the	process	of abstraction.	Theorists can even	mix and	match the two	approaches by	adopting	empiricist	processes	for	some	domains	of	abstraction	and nativist	processes	for	others.	What	will	determine	whether	the	process is	an	empiricist	or	nativist	one	isn't	merely	whether	abstraction	takes place	but	rather	the	character	of	the	innate	structure	of	the	similarity spaces	and	the	innate	constraints	that	guide	the	process	as	it	unfolds. (2) The Output of the Process of Abstraction Most of the mind's representations are complex representations. They have constituent structure in accordance with the principles of compositional semantics.	The	concept	white circle, for	example, is composed of the simpler concepts white and circle. Primitive representations, on the other hand, do not have compositional semantic	structure.	They	are	the	semantic	atoms	from	which	complex representations	are	built.	For	Locke,	many	of	the	products	of	abstraction However, other evidence suggests that the acquisition of color representations is guided by strong innate constraints. In an important	early	study,	Bornstein,	Kessen,	&	Weiskopf	(1976)	showed 4-month-old infants examples of a primary hue until the infants began to lose interest and then showed them novel instances of the	same	hue	as	well	as	equally	novel instances that	crossed	a	hue boundary.	For	example,	infants	were	familiarized	with	a	shade	of	blue (480-nm light; nm = nanometer) and subsequently shown a novel shade of blue (450-nm light) and an equally novel shade of green (510-nm light). The result	was that the infants looked significantly longer	at	the	novel	shade	of	the	new	hue	(green)	but	not	at	the	novel shade	of	the	old	hue	(blue).	Franklin	&	Davies	(2004)	have	recently replicated	these	findings	using	a	more	rigorous	metric	for	measuring distances	between	stimuli.	They	found	boundaries	not	only	between primary color categories (blue-green) but also between secondary color categories (blue-purple). Together	with the evidence	of adult variability from Roberson et al., this evidence suggests that the abstraction	process	may	begin	not	with	an	equipotent	innate	similarity space	with	no	category	boundaries	but	with	a similarity space that comes	with its own innately	bounded regions that are	modified in light	of later	experience.	Such	a	model is	still fully	compatible	with the	neo-Quinean	framework	for	abstraction.	It's	just	a	model	in	which the	selection	process	is	a	nativist	one,	involving	adjustments	around innately	specified	boundaries	in	the	similarity	space. Other	evidence that suggests that the learning	process is	guided by nativist constraints points in the direction of a different sort of nativist	model. For example,	Terry	Regier and colleagues examined color naming in 110 languages from nonindustrialized societies around the	world (Regier,	Kay,	&	Cook	2005).	They found that the best examples of color terms across this diverse sample tended to cluster	around	the	best	examples	of	the	English	terms	'black', 'white', 'red',	'yellow',	'green',	and	'blue'.	On	an	empiricist	model,	this	is	highly surprising	-	if	there	are	no	built-in	ways	to	group	colors,	why	should people	in	every	culture	wind	up	with	highly	similar	best	examples	of stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 16 – vol.	12,	no.	19	(december	2012) we can take the input to the process of abstraction to be a set of representations of various specific shades within a similarity space (several particular shades of white, corresponding to the colors of several	experienced	white	objects).	A	selection	process	operating	on this input results in the	demarcation	of	a	field	within this similarity space (a region in the color space corresponding to whiteness is delimited). Let's suppose that this process also generates a new representation,	white,	that	is	linked	to	each	of	the	representations	in the	selected	field	such	that	the	activation	of	any	element	in	the	field brings about the activation of this new higher-level representation. Now	the	semantics	of	this	higher-level	representation	could	be	handled in	a	number	of	different	ways.	One	way	would	be	for	the	content	of the	representation	to	be	determined	by	its	causal	dependence	on	the environmental conditions that it has the function of responding to (Dretske	1995);	the	internal	representations	for	specific	shades	would simply mediate this mind-world link between external conditions (whiteness)	and	the	representation	white.	Elsewhere,	we	have	called such	mediating	factors	sustaining mechanisms (Margolis	1998;	Laurence &	Margolis	2002).	A	sustaining	mechanism	doesn't	directly	determine a representation's content but indirectly makes its contribution by establishing the mind-world relation that does constitute the representation's content. On such an account, the products of the process	of	abstraction	-	representations	like	white, circular,	smooth, etc.	-	would	have their	content	determined	not	compositionally	but rather by the mind-world relations established by the sustaining mechanisms.18	Hence	abstraction	would	result	in	new	primitives.	So	it looks	like	it	is	possible	to	learn	new	primitive	concepts	via	abstraction on	the	neo-Quinean	framework. 18. Notice	that,	on	this	treatment,	the	representations	of	the	various	fine-grained shades aren't constituents of the general representation, unlike white and circle	in	white	circle.	Theorists	who	opt	for	sustaining	mechanisms	rather than	constituency	relations	often	do	so	because	it	weakens	the	relationship between	the	representations in	the	sustaining	mechanism	and	the	concept whose	content	is	indirectly	established,	thus	allowing	for	the	possession	of	a given	concept	across	a	great	deal	of	perceptual	and	cognitive	variability	(see Laurence	&	Margolis	1999,	Dretske	1981,	Fodor	1987). seem	to	have	been	primitive	representations	of	this	sort	(e. g.,	white). This raises the interesting question of	whether representations that are	learned	via	abstraction	within	the	neo-Quinean	framework	could be	primitive,	since	it	is	widely	assumed	that	primitive	representations cannot	be	learned.	As	Steven	Pinker	describes	the	consensus: On	the	nurture	side,	empiricists	tend	to	make	do	with	the abstemious	inventory	of	sensori-motor	features,	invoking only the process of association to build	more complex ones.	On	the	nature	side,	nativists	argue	that	a	larger	and more	abstract	set	of	concepts,	such	as	"cause,"	"number," "living	thing,"	"exchange,"	"kin,"	and	"danger,"	come	readymade	rather	than	being	assembled	onsite. Both	sides, if	pressed,	have to	agree that the	simple building blocks of cognition	-	like the keys on a piano, the	alphabet in	a typewriter,	or the	crayons in	a box	-	must themselves be innate. Type on a standard typewriter all you	want; though you can	bang	out any number of English words and sentences, you'll never see a single character of	Hebrew	or	Tamil or Japanese. (Pinker	2007,	p.	93) According	to	this	building blocks model of	representational-conceptual development, the	primitive representations	must	be innate,	and the rest of our representations and concepts are assembled from these primitives.	However,	if	abstraction	offers	a	way	to	learn	new	primitive representations, then it	argues	against the	building	blocks	model. It would	show	that	a	compelling	and	extremely	influential	view	about the	origins	of	concepts	is	misguided.17 One	of	the	benefits	of	having	an	explicit	framework	for	understanding abstraction	is	that	it	renders	such	questions	tractable.	Consider	again the	case	of	color	representations.	Given	the	neo-Quinean	framework, 17. If	new	primitives	can	be	learned	via	abstraction,	this	would	strengthen	the case	that	we've	made	elsewhere	against	the	building	blocks	model	(Laurence &	Margolis	2002);	see	also	Carey	(2009). stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 17 – vol.	12,	no.	19	(december	2012) which	precise	shade	is	at	issue,	it's	important	not	to	fixate	too	strongly on	any	particular	shade. For	purposes	of	this	paper,	we	don't	need	to	settle	the	question	of whether	abstracted	representations	are,	in	fact,	primitive.	We	simply want to call attention to the fact that the neo-Quinean framework allows	for	the	possibility	that	new	primitives	can	be	learned.	Since standard theories of development so often suppose that new primitives must be innate, this is a possibility of considerable philosophical interest. On the model we have sketched, the neoQuinean framework would allow us to acquire new primitive concepts,	thereby	increasing	the	combinatorial	expressive	power	of our	representational-conceptual	system. (3) Is Abstraction Uniquely Human? As	Locke	sees	things,	the	ability	to	form	abstract ideas	is	a	uniquely human capacity, one that is associated with our linguistic abilities. Locke	takes	the	fact	that	animals	don't	use	public	signs	to	be	a	good indication	that	they	aren't	able	to	have	any	general	ideas	at	all: ...	the	power	of	Abstracting	is	not	at	all	in	them;	and	that the	having	of	general	Ideas, is	that	which	puts	a	perfect distinction	between	Man	and	Brutes;	and	is	an	Excellency	which	the	Faculties	of	Brutes	do	by	no	means	attain to. For it is evident,	we observe no foot-steps in them, of	making	use	of	general	signs	for	universal	Ideas;	from which we have reason to imagine, that they have not the	faculty	of	abstracting,	or	making	general	Ideas,	since they	have	no	use	of	Words,	or	any	other	general	Signs. (1690/1975,	II,	xi,	§10) Locke	is	not	alone	in	these	views.	Thomas	Reid,	for	one,	wholeheartedly agrees that animals "have not the powers of abstracting and generalizing;	and that in this	particular,	Nature	has	made	a specific difference	between	them	and	the	human	species"	(Reid	1785/2002,	p. This sort of model isn't mandatory, however, and other models that	are	consistent	with	the	neo-Quinean	framework	would	have	the output	of	the	process	of	abstraction	be	a	complex	representation,	not a primitive.	Once again, consider the case of color representations. As	before,	we	can	take	the input to	abstraction	on	the	neo-Quinean framework to be a set of representations of various specific shades within a similarity space, and a selection process will result in the demarcation	of	a	field	within	the	similarity	space.	This	time,	though, we	will	suppose	that	this	process	also	generates	a	new	representation that	is	a	disjunctive	representation	whose	many	disjuncts	are	just	the representations that appear in the demarcated	field.	On this	model, the	semantics	of	the	abstracted	representation	is	plainly	compositional. The	content	of	white	is	a	function	of	the	contents	of	its	constituents and	the	compositional	structure	in	which	they	inhere. Both the compositional model and the sustaining mechanism model	are	compatible	with	the	neo-Quinean	framework.	Abstraction can	produce	complex	representations	that	incorporate	the	fine-grained representations that are the input to the process, or it can produce simple	representations	that	are	activated by sustaining mechanisms	that incorporate the fine-grained representations. Nonetheless, several considerations	suggest	that	the	sustaining	mechanism	model	may	be preferable.	One	is	the	computational	load	for	processes	that	occur	at the	level	of	the	abstracted	representation.	If these	processes	have	to operate	on	a	highly	structured	representation	and	deal	with	each	of its	numerous constituents, this is likely to	place	a	heavy	processing burden	on	the	system.	On	the	other	hand, if the	processes	can	stick to an unstructured representation and ignore all of the structure that is inherent in its sustaining mechanism, the computational load would be considerably eased. There may also be advantages in the informational loss that is inherent to the employment of an unstructured	representation.	For	example,	if	what	matters	in	applying a	learned	rule	is	the	more	general	category	white,	then	a	representation that	focuses	attention	on	just	that	category	(and	not	on	some	particular shade)	puts	the	emphasis	just	where	it	should	be.	If	it	doesn't	matter stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 18 – vol.	12,	no.	19	(december	2012) just to the items in the	training	regimen	but	also to	novel instances of the category they exemplify. For instance, in a representative and	now	classic study,	Herrnstein	and	his colleagues (1976) trained pigeons	to	distinguish	pictures	of	trees.	The	subtlety	involved	in	these discriminations is impressive, since the training set is very diverse and the contrasting stimuli are, in	many respects, highly similar to exemplars	of	the	target	category	(e. g.,	while	Herrnstein	et	al.'s	pigeons had	to	give	a	positive	response	to	a	picture	that	showed	just	the	top corner	of	a	tree	in	the	background	of	a	scene,	they	had	to	give	negative response	to	a	picture	that	showed	a	celery	stock	front	and	center	with its	leaves	intact).	Though	it	is	possible	that	the	general	representation tree is innate in pigeons, other	work leaves no	doubt that pigeons are capable of learning new general representations. Pigeons have been trained to selectively discriminate such artificial categories as automobiles and chairs (Lazareva, Freiburger,	&	Wasserman 2004). They	have even	been trained to	discriminate	Monets from	Picassos, and Stravinsky from Bach (Watanabe, Sakamoto, & Waikta 1995; Porter	&	Neuringer 1984).	Our neo-Quinean framework provides a plausible	account	of	how	the	underlying general	representations	are learned.	According	to	this	framework,	the	animals	initially represent fine-grained	(yet	fully	general)	perceptual	properties	of	the	stimuli	and, through	training,	come	to	represent	broader	categories	in	a	previously established	similarity	space. Quine	himself,	we	should	point	out,	does	recognize	that	nonhuman animals are capable of generalizing. Unfortunately, he draws the wrong moral from this similarity between humans and animals, suggesting	that	our	apparently	sophisticated	inductive	abilities	should be	downgraded	to	"an	animal"	model. [O]ther animals are like	man.	Their expectations, if	we choose	so to	conceptualize their	avoidance	movements and salivation and pressing of levers and the like, are clearly dependent on their appreciation of similarity. Or to put matters in their methodological order, these 388).	And	a	number	of	contemporary	philosophers	have	picked	up	on at least the strand	of	Locke's view that ties the	notion	of a concept to language, claiming that animals lack	bona	fide	concepts	because they lack the	necessary	participation in	a linguistic	community (e. g., Davidson	1975,	Dummett	1994,	McDowell	1994).19	Though	we	can't	go into	the	issues	regarding	concept	possession,	we	do	want	to	address the	question	of	whether	animals	must	lack	general	representations	and, more	significantly,	whether	the	capacity	for	abstraction	as	understood in	the	neo-Quinean	framework	sets	us	apart	as	a	species. To	begin,	we	should	note	that	it	is	by	applying	general	representations to	individuals,	and	by	relating	one	general	representation	to	another, that	agents	are	able	to	draw	inferences,	form	expectations,	and	learn from	experience.	Most	animals	would	not	survive	very	long	without them.	A	deer	might	manage	to	quench	its	thirst	when	drinking	from a pool of water, but no matter how	many pools it drinks from, it wouldn't be able to infer that the	next	pool is also able to	quench its	thirst.	Similarly,	a	wildebeest that	escapes	a lion's	attack	or	even multiple attacks wouldn't have the wherewithal to infer that the next lion	ought to	be avoided	because it too is dangerous. So it is unsurprising	then	that	psychologists	have	documented	that	general representations are widely distributed in the animal kingdom. As Richard	Herrnstein	notes	in	a	review	and	analysis	of	work	on	animals, categorization and hence general representation "has turned up at every level of the animal kingdom	where it has been competently sought"	(Herrnstein	1990,	p.	138). In	fact,	one	of	the	central	projects	in	animal	psychology	has	been	to determine	whether,	and	to	what	extent,	different	species	are	capable of discriminating sundry categories. Researchers routinely train animals	on	natural	and	artificial	stimuli	to	see	if	they	can	respond	not 19. Interestingly,	Locke's	claim	that	animals	do	not	use	any	public	signs	turns	out to	be	false.	Though	animals	don't	possess	anything	as	rich	as	human	natural language, there	are species	whose systems	of communication include	public signs that	are	under	an	animal's control, including	nonhuman	primates (Cheney	&	Seyfarth	1990),	meerkats (Manser	2001),	and	even the	humble chicken	(Evans,	Evans,	&	Marler	1993). stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 19 – vol.	12,	no.	19	(december	2012) A natural question, at this point, is to ask what other types of processes, besides neo-Quinean abstraction, might support the acquisition of general representations. This question is closely connected	with	a	number	of	important	philosophical	issues,	including the	influence	of	language	on	thought,	the	innate	structure	of	the	mind, the	origins	of	human	creativity, and the	nature	of theory change in science.	However	these	are	to	be	settled,	in	our	view,	there	is	no	one key acquisition system responsible for representational-conceptual development;	human	representational	and	conceptual	systems	stem from	a	highly	varied	collection	of	systems	of	acquisition.	Likewise,	the difference	between	human	and	animal	minds	does	not	depend	on	a single	powerful	source	from	which	all	uniquely	human	representations derive	but	instead	depends	on	an	eclectic	potpourri	of	sources. Just	to	give	a	flavor	of	this	diversity,	we	will	mention	two	proposals about	how	humans are able to acquire certain representations via cognitive resources that animals lack. The first is Susan Carey's proposal	that	many	concepts	can	only	be	learned	via	a	process	she refers to	as	bootstrapping (Carey	2009).	Bootstrapping	occurs	when an	agent	relies	on	an	uninterpreted	or	partially interpreted	symbol system	whose	symbols	act	as	placeholders	for	the	representations	to be	learned.	Interpreting	the	system	is	achieved	through	what	Carey calls	modeling processes.	These	typically involve	drawing	an	analogy between two systems of representation, the uninterpreted system and	a	system	that	already	has	some	meaning	for	the	learner.	Carey's flagship example of bootstrapping is an account of how children learn the positive integers.	On this account, children first have to learn	the	counting	procedure	as	a	meaningless	routine	and	also	have to	directly	pick	up	on	the	meanings	of	the	first	few	count	terms.	Then, after	a	protracted	period	and	much	effort, children	come to	see	an analogy	between	the	cognitive	models	they	use	in	connection	with the	first	few	count	terms	and	what	happens	with	the	sequence	in	the count	list.	The	idea	of	next word is	mapped	on	to	the	idea	of	adding a single individual to a set.	Carey	suggests	that	animals	aren't	capable of learning in this way, since they lack the ability to work with avoidance movements and salivation and pressing of levers and the like are typical of what we have to go on in mapping the animals' appreciation of similarity, their spacing of qualities. Induction itself is essentially only more of the same: animal expectation and habit formation.	(Quine	1969,	pp.	124–5) Quine gets things exactly backwards here, attempting to reduce a sophisticated representational	ability in	humans to	something	more brute in the form of an unexplicated notion of animal expectation. Contrary to what Quine suggests, inductive inference in humans requires	a	substantive	explanation,	one	that	implicates	representational states	and	processes.	And,	for	the	most	part,	animal	expectation	must be	understood	on	the	human	model	in	terms	of	representational	states and	processes.	Quine	seems	to	be	succumbing	to	the	tendency,	noted above,	to	be	content	with	a	superficial	treatment	of	ordinary	mental phenomena.	But	ordinary	mental	phenomena,	whether	in	humans	or in	animals,	mask	a	great	deal	of	complexity	that	our	explanations	need to	register	and	do	justice	to. In	any	event,	humans	are	by	no	means	special in their	ability to represent	general	categories,	nor, in	all likelihood, to	arrive	at them via	abstraction.	Of	course,	this	doesn't	mean	that	animals	are	capable of developing the very same general representations as humans. It ought	to	be	clear	enough	that	humans	can	develop	a	large	assortment of representations that are unavailable to other animals. In some cases, these	may be representations that do indeed require natural language, since they depend upon culturally acquired information that	cannot	be	conveyed	in	any	other	way.	In	other	cases,	they	may	be representations	that	are	grounded	in	domain-specific	representational systems	that	are	themselves	unique	to	the	human	lineage.	Regardless, it	shouldn't	be	controversial	that	general	representations	aren't	all	on a	par. It's	one	thing	to	have	a	general	representation	like	white	and quite	another	to	have	a	general	representation	like	proton. stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 20 – vol.	12,	no.	19	(december	2012) has	important	philosophical	implications.	It	speaks	to	such	questions as	how	to	understand	the	empiricism-nativism	dispute,	what	kind	of structure	concepts	have,	and	whether	humans	have	unique	conceptforming	abilities.	But	most	importantly,	the	neo-Quinean	framework offers	an	explicit treatment	of	an	otherwise	mysterious	process,	and because	of	this	explicitness,	it	allows	for	the	formulation	of	a	range	of realistic	possibilities	regarding	concept	acquisition. 5. Conclusion One	of	the	central	projects	in	the	philosophy	of	mind	is	to	explain	the origins	of	our	representational	capacities.	The	aim	of this	paper	has been	to	clarify	one	important	part	of	the	explanation	-	the	process	of abstraction	-	by providing an explicit framework for understanding how	it	works.	Just	as	Locke	supposed,	general	representations	can	be learned via a process that begins	with fine-grained experience that arises through	contact	with	particulars.	Abstraction	can	still explain the	acquisition	of	representations	with	greater	generality	from	more fine-grained	ones,	and it can	still explain the	acquisition	of	a	broad range of different kinds of general representations. However, on the	neo-Quinean framework that	we	have	presented, the	process	of abstraction	differs	from	the	traditional	empiricist	picture	in	a	number of	important	respects.	Unlike	the	traditional	notion	of	abstraction,	it	is perfectly	consistent	with	a	nativist	psychology	and	applies	to	humans and	animals	alike.	But	these	departures	from	the	traditional	empiricist picture are in	no	way	deficits of the	neo-Quinean framework.	They are	advantages,	giving	the	framework	greater	flexibility	and	broader applicability. Perhaps the most significant departure from the traditional empiricist picture is that the neo-Quinean framework requires a certain amount of general representation to be present from the start, so it cannot explain the acquisition of all general representations.	But	this	is	not	a	deficit	of	the	framework	either,	since no account can	do that.	We conclude that	while abstraction cannot be the	whole story	about the	origin	of	general representations, it is nonetheless	one	central	and	important	part	of	the	story. uninterpreted	symbol	systems	and	engage	in	the	modeling	processes that render them	meaningful. If she is right,	bootstrapping	may	be an	important	part	of	the	explanation	of	why	we	human	beings	have a conceptual system	whose expressive power far exceeds what is found	elsewhere. The other proposal we wish to mention is one that we have developed in previous work (Margolis 1998, Laurence & Margolis 2002). On this approach, some concepts depend upon an innate template	that	underlies	the	acquisition	of	a	range	of	concepts	in	a	given domain.	One	model that illustrates this	approach	has it that	human beings	have	a	template	for	animals	or	living	kinds	that	contains	slots for	information	regarding	properties	that	are	highly	indicative	of	kindmembership	-	shape,	color	markings,	characteristic	motion,	etc.	When a	learner	confronts	a	new	type	of	animal,	the	information	required	by the	template	is	associated	with	a	new	representation	whose	processing is	constrained	by	a	disposition	to	treat	kind-membership	as	a	matter of	having	an	underlying	nature	that	is	responsible	for	the	kind's	more accessible	properties.	We've	argued	that together	these	components can establish the	mind-world causal relation that is constitutive of a concept's content according to an information-based semantics approach.	A	similar	account	can	be	developed	for	artifact	concepts.	In this	case,	the	constraint	on	processing	is	perhaps	a	disposition	to	defer to the creator's intent regarding issues of kind-membership (Bloom 1996).	So	another	way	that	a	general	concept	might	be	acquired	is	for this	type	of	cognitive	machinery	to	be	engaged	when	a	learner	sees	a new	item	that	falls	under	the	purview	of	an	innate	template.	And	while animals may share some of the cognitive machinery that supports concept	acquisition	via	innate	templates,	it	is	doubtful	that	they	have the	very	same	templates	or	all	of	the	cognitive	dispositions	that	turn our templates into the	many	natural	kind	and	artifact concepts that occupy	much	of	human	thought. A	lot	more	could	be	said	about	the	neo-Quinean	framework,	but	we hope	that	these	brief	remarks	indicate	that	its	treatment	of	abstraction stephen	laurence	&	eric	margolis Abstraction and the Origin of General Ideas philosophers'	imprint – 21 – vol.	12,	no.	19	(december	2012) Dummett,	M.	(1994).	Origins of Analytical Philosophy.	Cambridge,	MA: Harvard	University	Press. Evans,	C.	S.,	Evans,	L.,	&	Marler,	P.	(1993).	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