Theseus,	Imparting	and	Exparting Wylie	Breckenridge Last	modified	8th	June	2018 1.	The	puzzle Here's	a	well-known	puzzle,	the	puzzle	of	the	ship	of	Theseus.	We	start	with	a	ship	at location	A.	We	replace	each	of	its	planks	one-by-one,	moving	the	old	planks	to	location B as	we	proceed. Eventually	we replace all of the planks, so that the ship has been totally	refurbished.	But	then	we	assemble	the	planks	at	location	B	into	a	ship,	so	that there	are	two	ships	–	the	ship	that	we	started	with,	at	location	A,	and	the	ship	that	we have just	built,	at location	B.	But	why	not	think	that the	ship	that	we	started	with is now	at	location	B,	having	been	dismantled	and	moved,	and	that	the	ship	at	location	A is	a	new	ship,	one	that	we	have	built	where	the	original	ship	used	to	be?	These	seem to	be	two	equally	good	ways	to	think	about	what	we	have	done.	So	which	of	the	two ships	(if	either)	is	the	original	ship,	and	why?	That's	the	puzzle. 2.	A	new	solution In	describing	the	puzzle	in	this	way	I	am	assuming	various	things:	that	there	is	a	ship	at the	start	of	the	process;	that	the	ship	has	planks	as	parts;	that	the	ship	can	lose	these planks; that the ship can gain	new	planks; that the ship can	have	a	plank	detached, moved and re-attached, all the	while staying part of the ship; that the ship can be totally refurbished (i.e. have all of its planks replaced); and that the ship can be disassembled	and	relocated.	Various	attempts	have	been	made	to	solve	or	dissolve	the puzzle	by	arguing	that	one	or	more	of	these	assumptions	is	false.	I	want	to	propose	a new solution, one that allows each of these assumptions to be true. I'm not sure whether	it	is	the	right	solution,	but	I'm	pretty	sure	that	it's	worth	taking	seriously. 3.	Changing	the	question Our	aim	is	to	answer	the	following	question:	At	the	end	of	the	process,	which	of	the two	ships	(if	either)	is	the	original	ship? I suggest that	we switch to a slightly different question: At the end of the process, where	(if	anywhere)	is	the	original	ship? If	we	can	answer	this	second	question	then	we	can	answer	the	first. If,	at	the	end	of the	process,	the	original	ship	is	at	location	A	then,	at	the	end	of	the	process,	the	ship	at location A is the original ship. If, at the end of the process, the original ship is at location	B	then,	at	the	end	of	the	process,	the	ship	at	location	B	is	the	original	ship.	If, at	the	end	of	the	process,	the	original	ship	is	somewhere	other	than	at	location	A	or	B (or	is	nowhere)	then,	at	the	end	of	the	process,	neither	the	ship	at	location	A	nor	the ship	at	location	B	is	the	original	ship. There	is	an	easy	answer	to	this	second	question:	At	the	end	of	the	process	the	original ship	is	wherever	its	planks	are.	If	its	planks	are	all	at	location	A	then	the	original	ship	is at	location	A.	If	its	planks	are	all	at	location	B	then	the	original	ship	is	at	location	B.	If some	of	its	planks	are	at	location	A	and	some	are	at	location	B	then	the	original	ship	is 2 partly	at	location	A	and	partly	at	location	B.	If	it	has	no	planks	then	the	original	ship	is nowhere	(it	might	not	even	exist). But	this	answer	raises	another	question:	At	the	end	of	the	process,	which	planks	are the	original	ship's	planks?	This	is	not	so	easy	to	answer.	It's	clear	where	all	the	planks are	then,	but	it's	not	clear	which	of	them	belong	to	the	original	ship.	At	the	start	of	the process	it	is	all	and	only	the	planks	at	location	A	that	belong	to	the	original	ship.	But	at the	end	of	the	process	it	might	not	be	these	planks	–	we	are	allowing	that	the	original ship	can	gain	and	lose	planks.	Things	might	change	during	each	step	of	the	process,	in which	a	plank	at	location	A	is	moved	to	location	B,	or	in	which	a	new	plank	is	moved	to location	A. So	what	we	need	to	know	is	this:	When	a	plank	is	moved	from	location	A	to	location	B is	it	still	a	part	of	the	original	ship?	And	when	a	new	plank	is	moved	to	location	A	does it	become	a	part	of	the	original	ship?	If	we	know	the	answers	to	these	questions	then we know which planks belong to the original ship at the end of the process, and thereby	know	where	the	original	ship	is	at	the	end	of	the	process,	and	thereby	know which	of	the	two	ships	at	the	end	of	the	process	is	the	original	ship. These	questions	are	just	as	hard	to	answer	as	our	original	question.	Consider	when	a plank	gets	moved	from	location	A	to location	B.	There	are	two	equally	good	ways	of thinking	about	what	happens.	Either:	the	plank	is	removed	from	the	original	ship	(i.e. stops	from	being	a	part	of	it)	and	is	discarded	to	location	B.	Or:	the	plank	is	still	a	part of the original ship but is detached and moved. Similarly for when a new plank is moved to location A – there are two equally good ways of thinking about what happens.	Either:	the	plank	is	added	to	the	original	ship	(i.e.	starts	being	a	part	of	it).	Or: the	plank	is	still	not	a	part	of	the	original	ship. What	determines	which	it	is?	Unfortunately	it	is	not	the	position	and	movement	of	the planks. That would be nice and simple, and also clear: we know the position and movement	of	the	planks	at	all	times.	But	when	a	plank	gets	moved	from	location	A	to location	B	whether	or	not	it is	still	a	part	of	the	original	ship	is	not	determined	by	its position	and	movement	–	its	position	and	movement	are	compatible	with	both	(a)	the plank	being	removed	as	a	part	and	discarded	to	location	B,	and	(b)	the	plank	remaining a	part	and	being	moved	to	location	B.	And	when	a	new	plank	is	moved	to	location	A whether	or	not	it	becomes	a	part	of	the	original	ship	is	not	determined	by	its	position and	movement	– its	position	and	movement	are compatible	with	both (a) the	plank becoming a part of the original ship, and (b) the plank not becoming a part of the original	ship. So	what	does?	I'll	now	propose	an	answer. 4.	Imparting	and	exparting We	are	allowing	that	things	can	gain	parts: it is	possible	for	there	to	be	x	and	y	such that	at	some	time	x	is	not	a	part	of	y	but	at	some	later	time	x	is	a	part	of	y.	When	this happens let's say that there has been an imparting. So an imparting occurs when something	x	which	is	not	a	part	of	something	y	becomes	a	part	of	y.	We	might	also	say 3 that	x	is	imparted	to	y.	So,	for	x	to	be	imparted	to	y	is	for	x	to	change	from	not	being	a part	of	y	to	being	a	part	of	y	(this	is	not	especially	a	change	to	x). We	are	also	allowing	that things	can lose	parts: it is	possible for there to	be	x	and	y such	that	at	some	time	x	is	a	part	of	y	but	at	some	later	time	x	is	not	a	part	of	y.	When this	happens	let's	say	that	there	has	been	an	exparting.	So	an	exparting	occurs	when something	x	which	is	a	part	of	something	y	becomes	not	a	part	of	y.	We	might	also	say that	x	is	exparted	from	y.	So,	for	x	to	exparted	from	y	is	for	x	to	change	from	being	a part	of	y	to	not	being	a	part	of	y	(again,	this	is	not	especially	a	change	to	y). I've	introduced	two	new	terms:	'imparting'	and	'exparting'.	As	far	as	I	can	see	we	don't already	have	words	for	imparting	and	exparting.	We	have	phrases	such	as	'x	becomes a	part	of	y',	and	'x	stops	being	a	part	of	y'	(these	are	the	best	natural	phrases	that	I	can come	up	with).	But	I'd	rather	not	use	such	long-winded	phrases,	especially	when	they are	cumbersome	(as	the	second	one	is).	It	will	be	better	to	have	a	new	term	for	each. The question I want to answer is this: What does it take for an imparting or an exparting	to	occur? Note that I am not looking for an account of what parthood is – of what it is for something x to be a part of something y. Nor am I looking for an account of what imparting	and	exparting	are	(I	have	defined	them	above).	I	am	looking	for	an	account of	what	it	takes	for	an	imparting	or	exparting	to	occur. My key proposal is that impartings and expartings are mind-dependent, in the following	sense: Impartings	and	expartings	require	someone	to	be	in	an	appropriate	mental	state (I'll	make	this	more	precise	below.) At least, I make this proposal for impartings to and expartings from things such as ships,	bicycles,	cars,	chairs,	buildings,	bridges,	and	so	on.	I	do	not	make	it	for	animals, trees,	planets,	and	so	on	(at	least	not	in	this	paper).	I'm	not	sure	how	to	draw	a	sharp line	between	the	things	to	which I intend it	to	apply	and	the	things	to	which I	don't. Using	'person-made'	doesn't	work	–	babies	are	person	made.	I'll	just	call	them	artifacts (this	might	not	be	the	right	word	to	use). I	can	be	more	precise.	For	definiteness	I	will	take	the	appropriate	mental	state	to	be	a decision.	Perhaps it	should	be	an intention	– I'm	not	entirely	sure.	But	that	wouldn't make	any	significant	difference	to	what I	am	going	to	say,	so I'll just	proceed	on	the assumption	that	it	is	a	decision.	In	the	case	of	imparting	it	is	the	decision	that	x	is	part of	y;	in	the	case	of	exparting	it	is	the	decision	that	x	is	not	part	of	y.	So	my	key	proposal is: Necessarily:	for	all	x	and	y:	x	is	imparted	to	y	only	if	there	is	a	z	such	that	z	decides that	x	is	part	of	y Necessarily: for all x and y: x is exparted from y only if there is a z such that z decides	that	x	is	not	part	of	y 4 Note	that	these	are	conditions	are	not	circular:	they	give	necessary	conditions	for	x	to become a	part	of	y	and for	x to	stop	being a	part	of	y	by	appealing to the	parthood relation,	but	there	is	nothing	circular	about	that	(as	there	might	be	if	they	were	giving necessary	conditions	for	x	to	be	a	part	of	y	and	for	x	to	not	be	a	part	of	y	by	appealing to	the	parthood	relation). Note also that these are just necessary conditions – they are not sufficient. Other things	are	required	for	something	to	become	a	part	of	something,	or	for	something	to stop	being	a	part	of	something.	I'll	mention	a	couple. First,	the	person	who	decides	must	have	the	appropriate	authority	over	both	x	and	y.	I can't	decide	that	your	bell	is	part	of	my	bicycle,	because	I	don't	have	the	appropriate authority over your bell (unless you give me the appropriate authority). Nor can I decide that my bell is part of your bicycle, because I don't have the appropriate authority over your bicycle (unless you give me the appropriate authority). It is an interesting	question	what it takes	to	have	the	appropriate	authority	over	something, but	it	is	a	difficult	one	and	not	one	that	I	will	try	to	answer	here	(I	won't	need	to). Second,	there	must	not	be	a	trumping	decision.	Suppose	that	you	and	I	both	have	the appropriate	authority	over	a	certain	bell	and	a	certain	bicycle.	Suppose	that I	decide that the bell is part of the bicycle, but you decide that it is not, and your decision trumps	mine.	Then	the	bell	is	not	imparted	to	the	bicycle,	even	though	someone	(i.e. me)	with	the	appropriate	authority	has	decided	that	it	is	part	of	the	bicycle.	Again,	it	is an	interesting	question	what	it	takes	for	one	decision	to	trump	another,	but	a	difficult one,	and	luckily	not	one	that	I	need	to	try	to	answer	here. There may be other necessary conditions. Perhaps some kind of performance is needed	–	in	the	case	of	imparting	perhaps	attaching	x	to	y,	or	saying	"x	is	part	of	y";	in the	case	of	exparting	perhaps	detaching	x	from	y,	or	saying	"x	is	no	longer	part	of	y". I'm	not	sure	whether	such	a	performance	is	required	–	I'm	not	asserting	that	it	is,	I'm just	suggesting	that	it	might	be. It will help to introduce some more terminology. Let CI(x, y, z) be the rest of the conditions that are required for x to be imparted to y by z ('CI' for 'conditions on imparting'),	and	let	CE(x,	y,	z)	be	the	rest	of	the	conditions	that	are	required	for	x	to	be exparted	from	y	by	z	('CE'	for	'conditions	on	exparting'). Then, I propose, we have the following necessary and sufficient conditions for an imparting	or	exporting	to	occur: Necessarily:	for	all	x	and	y:	x	is	imparted	to	y	iff	there	is	a	z	such	that	z	decides	that	x is	part	of	y	and	CI(x,	y,	z) Necessarily:	for	all	x	and	y:	x is	exparted	from	y	iff	there	is	a	z	such	that	z	decides that	x	is	not	part	of	y	and	CE(x,	y,	z) This	doesn't add	all that	much. It just	makes it clear that if conditions	CI(x, y, z) are satisfied	then	whether	or	a	thing	x	is	imparted	to	a	thing	y	comes	down	to	whether	or 5 not	a	certain	decision	is	made.	Similarly	for	exparting.	I	will	use	this	later	when	I	return to	solving	the	puzzle. 5.	A	general	phenomenon I have proposed that impartings and expartings are mind-dependent changes. This doesn't make them particularly special – there are many kinds of mind-dependent change.	Here	are	a	few	examples: Becoming	a	member	of	a	club Becoming	married Becoming	named Becoming	promised	to	do	something Each of these changes also requires someone to be in an appropriate	mental state, which	we	can	take	to	be	a	decision	(or	perhaps	it	should	be	an	intention).	For	someone x	to	become	a	member	of	a	club	y	requires	that	someone	z	decides	that	x	is	a	member of	y.	There	are	other	conditions	as	well:	z	must	have	the	appropriate	authority;	there must not be a trumping decision; perhaps there needs to be some kind of performance;	and	so	on.	Similarly	for	the	other	things	on	the	list. There	is	a	general	phenomenon	here.	My	proposal	is	that	imparting	and	exparting	are further	instances	of	this	phenomenon. There are many interesting and difficult questions that we might ask about this phenomenon:	What does it take to have the appropriate authority?	What happens when there is a clash of decisions, with none trumping the rest? Is some kind of performance actually required? Does the change require, for its persistence, the persistence of the mental state that was involved in bringing it about? Are these changes actually brought about, or is it just community belief that they have been brought about that is brought about? (If the latter then this might explain why a performance	is	required,	if	it	is). These are difficult questions, and they might raise deep problems. But any such problems	are	not	particular	to	imparting	and	exparting	–	they	are	problems	for	all	of these	kinds	of	changes. Imparting	and	exparting,	as	my	proposals	have	them,	are	no more	weird	or	problematic	than	the	many	other	mind-dependent	changes	that	there are. 6.	Obvious	counterexamples I	have	proposed	that: Necessarily:	for	all	x	and	y:	x	is	imparted	to	y	only	if	there	is	a	z	such	that	z	decides that	x	is	part	of	y Necessarily: for all x and y: x is exparted from y only if there is a z such that z decides	that	x	is	not	part	of	y 6 A	counterexample	to	the	first	is	a	possible	situation	in	which	there	is	an	x	and	a	y	such that	x	is	imparted	to	y	but	no	one	decides	that	x	is	a	part	of	y.	A	counterexample	to	the second	is	a	possible	situation	in	which	there	is	an	x	and	a	y	such	that	x	is	exparted	from y	but	no	one	decides	that	x	is	not	a	part	of	y. It	seems	easy	to	think	of	counterexamples.	Suppose	the	bell	on	my	bicycle	rattles	loose and falls	down	a long cliff,	never to	be seen	again.	Then the	bell	has	been	exparted from	my	bicycle,	but	no	one	decided	that the	bell is	not	part	of	my	bicycle.	This is	a counterexample	to	the	second	proposal. Well,	perhaps	not.	Is	the	bell	really	no	longer	part	of	my	bicycle?	Why	not	think	that	it is still part of	my bicycle, albeit a very remote one? It is no good to appeal to the movement and position of the bell to argue that it is no longer part of	my bicycle. Remember	that	we	are	proceeding	on	the	assumption	that	movement	and	position	do not	determine	whether	something	x	is	exparted	from	something	y,	and	we	are	looking for	something	else	that	determines	it.	So,	to	appeal	to	the	movement	and	position	of the	bell	to	argue	that	it is	no	longer	part	of	my	bicycle	just	begs	the	question	against my	proposal.	Without	some	independent	reason	to	think	that	the	bell	is	no	longer	part of	my	bicycle	we	should	not	accept	this	as	a	counterexample. There is something else to be careful of.	When you think about the situation that I have	described	you	might	be	adding	some	features	that	would	very	naturally	be	part of such a situation but that I haven't actually specified. If such a thing actually did happen to	my	bell, I	might	well decide that it is no longer	part	of	my	bicycle, albeit subconsciously	and	very	quickly.	After	all,	what	would	be	the	point	of	maintaining	that it is still part of my bicycle, given that it's never to be seen again? You might be imagining	that	to	be	part	of	the	situation,	because	it	would	be	a	very	natural	thing	to happen	in	such	a	situation. If	so	then	you	are	right	to	think	that	the	bell is	no	longer part of my bicycle. But such a situation is not a counterexample to the second proposal,	because	it's	one	in	which	the	relevant	decision	has	been	made. 7.	Two	other	objections Objection. If my proposals about imparting and exparting are right, then we can change	the	mass	of	some	objects	just	by	thinking.	For	the	mass	of	a	complex	object	is determined	by the	mass	of its	parts.	According to	my	proposals,	we can change the parts	of	an	object	just	by	thinking	(by	making	appropriate	decisions).	And	that	means that we can change its mass just by thinking. But we can't change the	mass of an object	just	by	thinking.	So	my	proposals	are	not	right. Reply.	It	depends	on	what	extra	conditions	are	required	for	imparting	and	exparting.	If imparting x to y also requires attaching x to y, and exparting x from	y also requires detaching x from	y, then	we cannot change the	parts	of something just	by thinking, and so	we cannot change the	mass of something just by thinking. But I'm skeptical whether	attaching	and	detaching	are	required.	I'm	inclined	to	think	that	a	decision	can be	sufficient.	If	so,	then	I	bite	the	bullet	on	this	objection.	But	then	I	would	think	of	it as an interesting consequence. (Keep in mind: we're not just deciding what the object's	mass is	–	we're	deciding	what things	are	parts	of it,	which then	determines what	its	mass	is.) 7 Objection. If my proposals about imparting and exparting are right, then ordinary objects	such	as	ships,	bicycles,	cars,	and	so	on,	can	travel	faster	than	light.	For	consider my bicycle in	my garage. I have a complete set of spares in	my back shed. I	might decide,	in	an	instant,	that	all	of	the	bicycle's	current	parts	are	no	longer	parts,	and	that all	of	the	spare	parts	in	the	back	shed	are	now	parts.	In	doing	so	I	have,	in	an	instant, moved	my bicycle from	my garage to	my back shed – faster than light. But it can't travel	faster	than	light	(as	physics	tells	us).	So	my	proposals	are	not	right. Reply. Again, it depends on what extra conditions are required for imparting and exparting.	If	imparting	x	to	y	also	requires	attaching	x	to	y,	and	exparting	x	from	y	also requires detaching x from y, then	we cannot change the parts of something just by thinking,	and	so	we	cannot	change	the	location	of	something	just	by	thinking.	But	if	a decision	can	be	sufficient	then	I	bite	the	bullet	on	this	objection	too,	and	take	it	to	be an	interesting	consequence.	(Keep	in	mind:	none	of	the	parts	travel	faster	than	light, and,	as	far	as	I	can	tell,	no	information	does	either.) 8.	Application	to	the	puzzle Now	back	to	the	puzzle.	Recall	that	to	figure	out	which	ship,	at	the	end	of	the	process, is the original ship we just need to figure out, each time a plank gets	moved from location	A	to	location	B,	whether	it is	still	a	part	of	the	original	ship	and,	each	time	a new	plank	gets	moved to location	A,	whether it	becomes	a	part	of the	original ship. That is,	we just	need	to	figure	out,	each	time	a	plank	gets	moved	from	location	A	to location	B,	whether	it	is	exparted	from	the	original	ship	and	to	figure	out,	each	time	a new	plank	gets	moved	to	location	A,	whether	it	is	imparted	to	the	original	ship. I	have	proposed	necessary	and sufficient conditions for	an imparting	or	exparting to occur.	According	to	this	proposal: When	a	plank	is	moved	from	location	A	to	location	B	it	is	exparted	from	the	original ship if	and	only if there is	a	z	such	that	z	decides	that	the	plank is	not	part	of	the original	ship	and	CE(the	plank,	the	original	ship,	z) When	a	new	plank	is	moved	to location	A	it is imparted	to	the	original	ship if	and only	if	there	is	a	z	such	that	z	decides	that	the	plank	is	part	of	the	original	ship	and CI(the	plank,	the	original	ship,	z) Recall	that	CE(the	plank,	the	original	ship,	z)	are	whatever	conditions	are	required,	in addition	to	the	appropriate	decision,	for	an	exparting	to	occur.	These	include:	z	having the	appropriate	authority	over	both	the	plank	and	the	original	ship,	there	not	being	a trumping	decision,	and	perhaps	other	things.	And	CI(the	plank,	the	original	ship,	z)	are whatever conditions are required, in addition to the appropriate decision, for an imparting	to	occur,	which	include	similar	things. Whether these conditions are satisfied is what determines what expartings and impartings	take	place,	and	thus	which	planks	belong	to	the	original	ship	at	the	end	of the	process,	and	thus	where	the	original	ship	is	at	the	end	of	the	process. 8 Suppose that the process is undertaken by a single person, the custodian of the original	ship,	who	has	the	appropriate	authority	over	the	original	ship	and	over	all	of the	planks	to	perform	whatever	expartings	and impartings	she	pleases.	Suppose	that there is	no	one	else involved	who	might	make	trumping	decisions.	And	suppose	that any	other	conditions in	CE	and	CI	are	satisfied.	Then	what	expartings	and impartings occur	comes	down	to	what	decisions	the	custodian	makes	during	the	process. Suppose	that	she	decides,	each	time	she	moves	a	plank	from	location	A	to	location	B, that it is	not	a	part	of	the	original	ship,	and	that	she	decides,	each	time	she	moves	a new	plank	to location	A, that it is	a	part	of the	original	ship.	Then,	at the	end	of the process,	it	is	all	and	only	the	planks	at	location	A	that	belong	to	the	original	ship,	and the	original	ship	is	at	location	A.	The	original	ship	has	been	fully	refurbished. Suppose that she does	not decide, each time she	moves a plank from location	A to location	B,	that	it	is	not	a	part	of	the	original	ship,	and	that	she	does	not	decide,	each time	she	moves	a	new	plank	to	location	A,	that	it	is	a	part	of	the	original	ship.	Then	no expartings	or impartings	occur	during	the	process,	and	so,	at	the	end	of	the	process, the	original ship	has	exactly the	same	planks	as it started	with,	which	are	now	all	at location B, and so the original ship is at location B. The original ship has been disassembled,	moved,	and	reassembled	at	location	B. Suppose	that	she	decides,	each	time	she	moves	a	plank	from	location	A	to	location	B, that it is	not	a	part	of the	original	ship,	and	that	she	does	not	decide,	each	time	she moves	a	new	plank	to	location	A,	that	it	is	a	part	of	the	original	ship.	Then	the	original ship	has	all	of	its	planks	exparted	but	has	no	new	planks	imparted,	so	at	the	end	of	the process	it	has	no	planks	at	all,	so	at	the	end	of	the	process	it	is	nowhere	(perhaps	it	no longer	exists). Suppose that she	does not decide, each time she	moves a plank from location	A to location	B,	that	it	is	not	a	part	of	the	original	ship,	and	that	she	decides,	each	time	she moves	a	new	plank	to	location	A,	that	it	is	part	of	the	original	ship.	Then	no	planks	are exparted	from	the	original	ship	but	all	of	the	new	planks	are	imparted	to	it.	So,	at	the end	of	the	process,	all	of	the	planks	are	a	part	of	the	original	ship,	and	the	original	ship is	partly	at	location	A	and	partly	at	location	B.	This	case	is	a	bit	weird	–	what	seems	to be	two	distinct	ships,	one	at location	A	and	one	at location	B, is	actually just	a	single ship partly at each location. Weird, but not impossible. (To help see that this is possible, consider the following variant case. Consider a car that	has a spare	wheel. The spare	wheel is part of the car, and is carried around	with it. Now add a spare muffler,	which	is	now	part	of	the	car	and	also	carried	around	with	it.	Now	add	a	spare seat,	a	spare	brake,	a	spare	engine,	and	so	on,	until	we	have	a	complete	set	of	spares, which,	to	make	it	easy	to	carry	all	of	these	spares,	we	assemble	and	tow	along.	What looks like two cars, one towing the other, is just a single car, part of which is a complete	set	of	spares.) Other combinations	of decisions are	possible, but it should	be clear enough	by	now what	the	result	is	in	each	case. So	that's	my	proposed	new	solution	to	the	puzzle. 9 9.	Two	final	thoughts At	the	moment	I	only	intend	my	proposals	about	imparting	and	exparting	to	apply	to artifacts	–	they	give	necessary	and	sufficient	conditions	for	something	to	be	imparted to an artifact, and	necessary and sufficient conditions for something to be exparted from	an	artifact.	What	about	non-artifacts?	Consider	a tree.	What	does it take for	a leaf,	say,	to	be	imparted	to	a	tree?	And	what	does	it	take	for	a	leaf	to	be	exparted	from a tree?	Are the conditions the same as the ones that I have proposed for artifacts? That	doesn't	seem	right	–	trees	had	leaves	as	parts	long	before	anyone	was	around	to make any decisions about parthood. But if imparting a leaf to a tree required a decision	then	those	leaves	could	never	have	become	parts	of	those	trees.	But	maybe	it is right?	Maybe trees	did	not	have leaves	as	parts	until	we came	along	and	decided them to be parts. I'm a little nervous about this idea, but it strikes me as worth considering.	Perhaps	my	proposals	apply	to	everything,	artifact	or	not. Confining our attention to artifacts, there is an interesting question of when some things compose an artifact (often called the 'special composition question'). On	my desk	right	now	there	is	a	mug	and	a	plate.	Is	there	also	a	thing	that	they	compose?	This would	require	the	mug	to	be	a	part	of	it	and	the	plate	to	be	a	part	of	it,	which	would require	the	mug	to	have	been	imparted	to	it	and	the	plate	to	have	been	imparted	to	it, which	would require, according to	my	proposals, someone to	have	decided that the mug	is	part	of it	and	that	the	plate	is	part	of it. If	no	such	decisions	have	been	made then	neither	the	mug	nor	plate	are	part	of	it,	which	means	that	the	mug	and	plate	do not compose it, so there is no thing that the mug and plate compose. But if such decisions	have	been	made	then	there	might	be.	Note	that	it	would	be	very	easy	for	me to make these decisions, thereby making it the case that the mug and the plate compose	something,	which	is	perhaps	why	we	are	so	puzzled	about	whether	there	is something	that	they	compose.