Forthcoming	in	Philosophy	and	Phenomenological	Research;	please	cite	official	version. 1 GROUNDING,	ESSENCE,	AND	IDENTITY Fabrice	Correia University	of	Neuchâtel Alexander	Skiles* New	York	University Abstract:	Recent	metaphysics	has	turned	its	focus	to	two	notions	that	are-as well	as	having	a	common	Aristotelian	pedigree-widely	thought	to	be	intimately related:	grounding	and	essence.	Yet	how,	exactly, the	two	are	related	remains opaque.	We	develop	a	unified	and	uniform	account	of	grounding	and	essence, one	which	understands	them	both	in	terms	of	a	generalized	notion	of identity examined	in	recent	work	by	Fabrice	Correia,	Cian	Dorr,	Agustín	Rayo,	and	others. We	argue	that	the	account	comports	with	antecedently	plausible	principles	governing	grounding,	essence,	and	identity	taken	individually,	and	illuminates	how the	three	interact.	We	also	argue	that	the	account	compares	favorably	to	an	alternative	unification	of	grounding	and	essence	recently	proposed	by	Kit	Fine. Recent	metaphysics	has	turned	its	focus	to	two	notions	that	are-as	well	as	having a common Aristotelian pedigree-widely thought to be intimately related: grounding	(when	some	phenomenon	non-causally	'derives'	from	another)	and	essence (when some phenomenon is in the 'nature' of another). However, how they're	related	remains	quite	opaque.1	We	aim	to	clarify	their	link	by	proposing	a unified	and	uniform	account	of	both	notions	that	analyzes	them	in	terms	of	a	third: what	we	call,	following	Linnebo	(2014),	generalized	identity.	Along	with	the	intrinsic	desirability	of	accounting	for	either	notion	alone	(which	has	proven	elusive), our	proposal	illuminates	how	the	two	interact	by	means	of	a	single,	relatively	wellbehaved	conceptual	tool. What	do	we	mean	by	"generalized"	identity?	Objectual	identities	(e.g.	"Hesperus	is Phosphorus") are familiar, and	display a canonical form: an identity-indicating * This	article is	the	product	of full	and	equal	collaboration	between	its	authors;	the	order	of authorship	is	alphabetical. 1 How grounding and essence interact is explicitly taken up in Audi (2012; 2015), Carnino (2014),	Correia	(2005;	2013),	Dasgupta	(2014;	2016),	Fine	(2012;	2015),	Guigon	(forthcoming), Greenberg	(2014),	Kment	(2014),	Koslicki	(2012;	2015),	Rosen	(2012;	2015),	Skiles	(2015),	Trogdon	(2015),	and	Zylstra	(forthcoming). 2 phrase	like	"is"	gets	treated	as	a	relational	predicate,	flanked	by	two	designators for	entities.	Despite	the	unfamiliar	name,	generalized	identities	are	no	less	philosophically	commonplace.	Consider: (1) For	a	thing	to	be	a	bachelor	is	for	it	to	be	an	unmarried	adult	male. (2) For	a	thing	to	know	a	proposition	is	for	it	to	truly,	justifiably	believe	that proposition. (3) For	the	Atlantic	Ocean	to	be	filled	with	water	is	for	it	to	be	filled	with H2O	molecules.2 These	statements	are	clearly	analogous	to	objectual	identities:	one	could	readily substitute	in	phrases	like	"is	the	same	as"	or	"is	no	different	than",	cancelling	any implication	that	the	"is"	at	issue	is	one	of	predication	or	existence.	Yet	they	deviate in	logical	form,	at	least	at	the	grammatical	surface.	"For	the	Atlantic	Ocean	to	be filled	with	water"	in	(3),	e.g.,	doesn't	seem	to	be	in	the	designating	business,	and the	truth	of	(3)	doesn't	seem	to	hinge	upon	its	being	so.	Surely	we	should	believe (3),	a	mundane	chemical-geological	truth,	even	if	metaphysical	inquiry	reveals	no 'fact-shaped'	entities	with	just	the	right	individuation	conditions	(Cameron	2014, p.	431;	Dorr	2016,	pp.	40-1;	Rayo	2013,	pp.	66-8).	And	certain	examples	patently resist	a	straightforward	objectual	reading.	Consider: (4) For	a	thing	to	be	a	non-self-instantiator	is	for	it	to	be	a	property	that doesn't	instantiate	itself. Familiar	Russellian	reasoning	demonstrates	that	there	is	no	such	property	being a	non-self-instantiator,	raising	obvious	trouble	for	the	view	that	(4)	expresses	an identity	involving	it	(Correia	2006,	pp.	761-2;	Dorr	2016,	p.	40).3 2 For	additional	examples	of	the	idiom,	see	Correia	(2010,	pp.	256-7),	Dorr	(2016,	p.	39),	King (1998,	p.	156),	Kment	(2014,	p.	153),	Koslicki	(2012,	pp.	197-203),	and	Rayo	(2013,	p.	3). 3 Those	who, like	us,	deny	that	that	generalized identities	are	objectual identities in	disguise might	nonetheless	uphold	the	following,	more	cautious	principles: (i) If	the	property	of	being	F	and	the	property	of	being	G	both	exist,	then	for	a	thing	to be	F	is	for	it	to	be	G	iff	the	property	of	being	F	=	the	property	of	being	G. (ii) If	the	fact	that	p	and	the	fact	that	q	both	exist,	then	for	it	to	be	the	case	that	p	is	for	it to	be	the	case	that	q	iff	the	fact	that	p	=	the	fact	that	q. 3 Although	not	themselves	objectual	identities,	recent	studies	have	shed	light	on	the nature,	logic,	and	epistemology	of	generalized	identities	by	extending	principles widely	thought	to	govern	objectual identity, to	cover	the	"is"	of	statements like (1)-(4).4	A	common	refrain-a	crucial	one	for	our	purposes-is	that	generalized identity	needn't	only	be	full,	as	in	(1)-(4).	It	can	also	be	partial,	as	when	one	says that	for	a	proposition	to	be	known	is	in	part	for	it	to	be	true	(but	not	in	full,	since it	must	also	be	justifiably	believed).	Current	work	focuses	on	partial	generalized identities	of	the	conjunctive	variety,	like	the	one	mentioned.	Yet	it	also	comes	in	a disjunctive	variety,	and	both	are	analyzable	in	terms	of	the	full.	Distilled	to	its	core, our	account	unifies	grounding	and	essence	by	analyzing	essence	in	terms	of	the conjunctive	variety,	and	grounding	in	terms	of	the	disjunctive	variety. Here's	our	plan.	In	section	1,	we	further	introduce	the	notion	of	generalized	identity.	In	sections	2	and	3,	we	develop	accounts	of	essence	and	grounding	in	terms of	generalized identity,	respectively. In	section	4,	we	argue	that the framework compares	favorably	to	a	unification	of	grounding	and	essence	recently	proposed by Fine (2015). Finally, in section 5	we conclude	with several open questions about	generalized	identity	to	guide	future	research	on	grounding	and	essence. 1. Generalized	identity Our	take	on	generalized	identity	builds	on-yet	in	certain	key	respects	deviates from-frameworks	put	forward	by	Correia	(2010;	2016),	Rayo	(2013),	and	Dorr (2016).	Space	limitations	preclude	a	full	development	and	comparison,	so	we	concentrate	only	on those	elements	of the resulting theory	most relevant for later purposes. We	(the	authors)	disagree	over	these	principles,	due	to	certain	background	disagreements	regarding	the	nature	and	existence	of	properties	and	facts.	Fortunately,	for	present	purposes	we	can	let these	disagreements	lie:	neither	(i)	nor	(ii)	is	assumed	in	the	course	of	what	follows.	(But	see	the end	of	section	3.2	for	some	remarks	on	views	which	endorse	(i)	or	(ii).) 4 See	Correia	(2010;	2016),	Dorr	(2016),	Linnebo	(2014),	and	Rayo	(2013).	Also	pertinent	is	the critical	discussion	of	Rayo's	distinctive	theory	and	applications	of	the	notion	in	his	The	Construction	of	Logical	Space:	see	Cameron	(2014),	Eklund	(2014),	Greco	(2015),	Hofweber	(2014),	Russell (2014),	Sider	(2014)	and	Turner	(2015),	and	see	Rayo	(2014;	2015b)	for	replies. 4 Following	Rayo,	we	express	generalized	identity	with	an	operator,	o,	indexed	by zero	or	more	variables,	which	takes	two	open	or	closed	sentences	and	yields	another.	Where	p	and	q	are	open	or	closed	sentences, (5) p o	q should	be	read	as	"For	it	to	be	the	case	that	p	is	for	it	to	be	the	case	that	q";	and where	F	and	G	are	monadic	predicates, (6) Fx	ox	Gx should	be	read	as	"For	a	thing	to	be	F	is	for	it	to	be	G".5 More	generally,	a	statement of	the	form (7) p	ox,	y,	...	q should	be	read	as	"For	some	things	x,	y,	...	to	be	such	that	p	is	for	them	to	be	such that	q".6	We	read	such	statements	as	not	requiring	that	the	flanking	expressions be	true/satisfied:	for	instance,	it	is	intuitively	no	objection	to	(1)	that	there	aren't any	bachelors.	For	short,	we	read	them	non-factively.	We	call	type-(5)	statements factual	identities,	and	call	type-(7)-and	therefore	type-(6)-statements	generic identities. Although	it's	tempting	to	read	"For	...	is	for	___"	statements	as	indicating	a	type	of priority	of	one	side	to	the	other, o	is	instead	to	be	read	as	what	Rayo	evocatively calls	a	"no-difference	operator"	(2014,	pp.	518).	Accordingly,	we	take	it	to	behave 5 Here	and	elsewhere,	we	fudge	typical	use-mention	conventions	when	no	confusion	should	result,	and	allow	context	to	sort	out	whether	we	use	"identities"	to	refer	to	statements	about	what	is identical	to	what	vs.	the	identities	out	there	in	the	world	(so	to	speak). 6 Note	that	in	such	a	statement,	the	variables	x,	y,	...	need	not	bind	all	free	variables	in	p	and	q: to	use	an	example	of	Dorr's	(2016,	p.	48),	to	assume	otherwise	precludes	quantified	generalized identity	statement	like	"$y(x	is	German	ox	x	is	from	y)",	which	are	surely	sensible.	Also	note	that we	focus	on	cases	in	which	o	binds	first-order	and	singular	variables	to	simplify.	In	fact	there	are examples	plausibly	regimented	with	o	instead	binding	higher-order	variables	(as	in	"For	it	to	be possible	that	p	isp	for	there	to	be	a	spatiotemporally	isolated	universe	in	which	p";	cf.	Lewis	1986) or	plural	variables	(as	in	"For	xx	to	be	countably	infinite	isxx	for	xx	to	one-one	correspond	to	the natural	numbers");	cf.	Rayo	(2013,	p.	146)	and	Dorr	(2016,	pp.	49	ff.).	Working	with	this	broader class	of	generalized	identities	would	allow	us	to	extend	our	accounts	of	grounding	and	essence	in correspondingly	broader	ways,	but	doing	so	would	complicate	matters	too	much	here. 5 like	the	familiar	no-difference	predicate	for	what	we've	called	objectual	identity (a.k.a.	=).	As	such,	we	take	o	to	be	reflexive,	symmetric,	and	transitive,	i.e.	that	the following	hold	for	any	p,	q,	and	r,	and	any	sequence	v	of	zero	or	more	variables: Reflexivity: p	ov	p Symmetry: If	p	ov	q,	then	q	ov	p Transitivity: If	p	ov	q	and	q	ov	r,	then	p	ov	r The	truth	of	p	ov	q	also	allows	for	representational	differences	between	p	and	q. Except	in	the	trivial	reflexive	cases,	there	is	a	syntactic	difference	between	them, and	perhaps	further	differences	in	their	semantic	values	or	cognitive	uptake	(e.g. the	'guise'	their	contents	are	presented	under).	But	such	differences	no	more	undermine	a	generalized	identity	than	those	between	"Hesperus"	and	"Phosphorus" undermine	the	truth	of	"Hesperus	=	Phosphorus"	(cf.	Dorr	2016,	pp.	42-6;	Rayo 2013,	pp.	52-4). We	also	take	it	that	some	(interesting)	restriction	of	Leibniz's	Law	for	o	must	be correct: LL: If	p	ov	q	and	F,	then	F[q//p] where	F[q//p]	results	from	sentence	F	by	replacing	one	or	more	occurrences	of	p	by	q,	with	the	condition	that	no	variable	that	is	free	in	p	ov	q is	bound	in	F	or	F[q//p]	(see	Dorr	2016,	p.	49) We	say	"some	restriction",	because,	just	like	its	objectual	counterpart,	the	law	fails if	understood	unrestrictedly.	Belief	ascription	contexts	provide	clear	counterexamples:	granted	that	for	a	thing	to	be	a	water	molecule	is	for	it	to	be	an	H2O	molecule,	we	cannot	infer	that	John	believes	that	his	glass	is	filled	with	H2O	molecules from	the	assumption	that	he	believes	that	his	glass	is	filled	with	water	molecules. Other	clear	examples	of 'opaque' linguistic	contexts	are	quotation	contexts,	and contexts	like	"the	proposition	that	...	is	distinct	from	the	proposition	that	___"	and "the	concept	of	being	...	is	distinct	from	the	concept	of	being	___"	on	a	sufficiently fine-grained conception of propositions and concepts, respectively (see Dorr 2016,	pp.	43-46	and	53-54). Determining	exactly	which linguistic	contexts	are 6 opaque	for	objectual	identity	is	no	easy	task,	and	the	situation	is	no	different	in	the case	of	generalized	identity.	Fortunately,	we	won't	need	to	provide	a	detailed	discussion	of	the	issue,	and	we	trust	the	reader	will	agree	with	us	that	our	applications	of	LL	will	always	involve	contexts	that	are	clear	candidates	to	be	transparent (or	at	least	not	clear	candidates	to	be	opaque).7 As	with	objectual identity,	generalized	identity	is	tightly linked	to	metaphysical necessity.	Specifically	(and	ignoring	non-monadic	cases): (8) If	Fx	ox	Gx	then	£"x£(Fx	iff	Gx) (9) If	p o	q, then	£(p iff	q) We	are	indeed	happy	to	hold	that	the	contexts	"£"x£(Fx	iff	...)"	and	"£(p iff	...)" are	transparent	for	generalized	identity,	and	hence	to	derive	these	principles	from LL.	But	we	reject	the	converses	of	(8)	and	(9): (10) If	£"x£(Fx	iff	Gx),	then	Fx	ox	Gx (11) If £(p	iff	q),	then	p	o	q We	strain	to	hear	an	intuitive	reading	of	o	(that	treats	it	as	a	no-difference	operator	akin	to	=,	anyway)	that	verifies	all	instances	of	(10)	and	(11).	Given	how	Goodman	(1955)	defines	"grue"	and	"bleen",	(10)	has	the	seemingly	false	consequence that	to	be	green	is	to	be	either	grue-if-observed-no-later-than-3000-A.D.	or	bleenif-observed-afterward	(see	Dorr	2016,	pp.	70-1	for	discussion	of	this	example	in	a related context). Given the standard assumption that	mathematical and logical truths	hold	necessarily,	(11)	has	the	seemingly	false	consequence	that	for	to	2+2 to	equal	4	is	for	everything	to	be	self-identical.8 7 Thanks	to	a	referee	for	pressing	us	to	clarify	here.	We	should	add	that	we	also	believe	that	the context	"...	ov	___"	is	an	archetypical	example	of	a	transparent	context	(cf.	Dorr	ibid.),	and	hence	we are	happy	to	derive	the	symmetry	and	transitivity	of	o	from	its	reflexivity	using	LL,	in	the	same way	that	the	symmetry	and	transitivity	of	=	is	standardly	derived	from	its	reflexivity	using	Leibniz's	Law	for	=. 8 For	another	counterexample,	see	Cameron	(2014,	p.	431).	Though	Rayo	(2013)	endorses	(10) and	(11),	we	lack	the	space	to	evaluate	his	motivation	and	defense	of	these	principles	here,	which relies	on	some	highly	contentious	stances	that	Rayo	takes	about	e.g.	the	nature	of	modality,	which those	who	theorize	with	generalized	identity	per	se	needn't	adopt	(cf.	Linnebo	2014,	fn.	26). 7 Here's	one	advantage	of	treating	(8)-(11)	as	logically	valid,	though:	a	logic	for	o follows	from	one's	preferred	modal	logic	for	£	automatically.	Since	we	reject	(10) and	(11),	things	aren't	so	easy	for	us.	Luckily,	we	can	focus	on	a	narrower	question where	progress	has	been	made:	which	truths	of	type	p	ov	q	hold	as	a	matter	of	the logical	form	of	p	and	q? Correia	(2016)	provides	what	we	take	to	be	a	correct	partial	answer	for	the	case of factual identity.9	Start	with	a standard	propositional language	with	negation (¬),	conjunction	(Ù),	and	disjunction	(Ú)	left	primitive,	and	define	the	formulas	as usual.	Correia	argues	from	semantic	considerations	that	the	logical	truths	of	the form	p	o	q,	where	p	and	q	are	formulas	in	the	language	defined,	are	just	the	theorems	of	the	system	we	call	"GI",	defined	by	the	following	axioms	and	rules	(structurally	analogous	principles	are	listed	horizontally): Axioms	of	GI: A1. p	o	¬¬p A2. p	o	p	Ù	p A3. p	o	p	Ú	p A4. p	Ù	q	o	q	Ù	p A5. p	Ú	q	o	q	Ú	p A6. p	Ù	(q	Ù	r)	o	(p	Ù	q)	Ù	r A7. p	Ú	(q	Ú	r)	o	(p	Ú	q)	Ú	r A8. ¬(p	Ù	q)	o	¬p	Ú	¬q A9. ¬(p	Ú	q)	o	¬p	Ù	¬q A10. p	Ù	(q	Ú	r)	o	(p	Ù	q)	Ú	(p	Ù	r) Rules	of	GI: R1. p	o	q	/	q	o	p R2. p	o	q,	q	o	r	/	p	o	r R3. p	o	q	/	p	Ù	r	o	q	Ù	r R4. p	o	q	/	p	Ú	r	o	q	Ú	r 9 We	are	aware	that	the	correct	logic	of	generalized	identity	remains	a	matter	of	controversy; cf.	Dorr's	(2016)	detailed	discussion	in	sections	6,	7	and	8	for	some	key	points	of	dispute.	However, we	believe	that	our	account	of	grounding	and	essence	in	terms	of	generalized	identity	is	compatible	with	a	range	of	different	views	about	the	logic	of	the	notion.	Given	the	popularity	of	the	theory of	structured	propositions	and	its	virtues	for	the	purpose	of	semantic	theorizing,	it	is	both	natural and	appropriate	to	wonder	whether	this	range	of	views	includes	the	view	that	factual	identities are	equivalent	to	objectual	identities	between	such	propositions.	In	line	with	a	previous	remark (see fn.	3),	we	want	to	remain	neutral	on	whether factual identities	are	equivalent to	objectual identities	between	structured	propositions	when	the	latter	are	available.	But	we	want	to	stress that	for	a	view	of	that	kind	to	be	viable,	it	should	not	involve	a	too	fine-grained	conception	of	propositions.	Similar	considerations	apply	to	theories	of	structured	properties. 8 Importantly,	the	dual	of	A10, A11. p	Ú	(q	Ù	r)	o	(p	Ú	q)	Ù	(p	Ú	r), isn't	a	theorem	of	GI,	and	a	rule	for	negation	corresponding	to	R3	and	R4, R5. p	o	q	/	¬p	o	¬q, doesn't	preserve	theoremhood	in	GI.	(Given	A1-10	and	R1-4,	adding	A11	turns	out equivalent	to	adding	R5:	see	Fine	2016,	pp.	204.) GI is neatly related to systems characterizing notions of equivalence more coarsely	grained than factual identity.	Adding	A11	or	R5	yields	Angell's (1989) first-degree system for analytic equivalence (adding A11 actually yields Fine's 2016a	axiomatization	of	that	system).	For	another	comparison,	consider: A12. p	o	p	Ù	(p	Ú	q) A13. p	o	p	Ú	(p	Ù	q) As	Angell	(1977)	stresses,	adding	either	A12	or	A13	as	axioms	to	the	(1989)	system-which	are	provably	equivalent	in	GI,	which	this	system	contains	as	a	fragment-yields the logic	of	mutual first-degree	entailment	of	Anderson	&	Belnap (1962;	1963).	Adding	either	A14	or	A15	to	Anderson	&	Belnap's logic	makes	o behave	like	classical	logical	equivalence: A14. p	o	p	Ù	(q	Ú	¬q) A15. p	o	p	Ú	(q	Ù	¬q) (A14	and	A15	are	already	equivalent	in	Angell's	system.) Since	our	main	interest	here	are	applications	of	generalized	identity-leaving	only so	much	space	to	investigate	its	theory-we'll	make	some	(we	think	reasonable) assumptions.	We	assume	that	GI	specifies	which	factual	identities	hold	as	a	matter of	the	truth-functional	logical	form	of	their	flanking	expressions,	and	that	R1-R4 aren't	only	validity-	(i.e.	logical	truth-)	preserving,	but	also	truth-preserving.	We also	assume	that	the	generic	operators	ox,	y,	...	logically	behave	in	much	the	same way	as	the	factual	operator	o	(which	is	not	to	say	that	extra	principles,	specific	to 9 these	operators,	are	not	required;	see	e.g.	Dorr's	(2016,	p.	49)	principle	of	Alphabetic	Variation).	Finally,	we	grant	ourselves	the	resources	to	quantify into	nonnominal	positions	occupied	by	predicational	and	sentential	expressions,	and	that doing	so	needn't	be	read	as	covertly	ranging	over	a	domain	of	entities.10	Yet	we won't	need	the	full	strength	of	all	these	claims	in	what	follows.	We	will	indicate exactly	which	postulates	for	generalized	identity	we	take	for	granted	and	why,	and why	we	reject	certain	principles	validated	by	logics	for	coarser	notions	of	equivalence. Finally,	we adopt the	working hypothesis that generic and factual identity are pieces	of	primitive ideology.	Cowling (2013) argues-convincingly,	we think- that	when	determining	how	ideologically	committed	a	theory	is,	one	should	count the	kinds	of	primitive	ideology	it	employs,	not	each	piece	individually.	Though	we find	it	intuitively	natural	to	group	=,	ov,	and	o	together,	and	thus	that	taking	the latter	two	as	primitive	is	no	more	ideologically	profligate	than	taking	the	first	as primitive	alone,	we	needn't	press	the	case	further	here.11	Our	primary	goal	is	to analyze	two	other	notions	that	many	take	as	distinct	kinds	of	primitive	ideology: grounding	and	essence.	Given	that	all	these	notions	must	be	accounted	for	somehow,	our	account	leaves	one	no	more	ideologically	loaded	than	before:	either	one starts	with	at	most	four	kinds	(grounding	and	essence;	objectual	and	non-objectual	identity)	and	ends	with	at	most	two,	or	one	decreases	instances	of	primitive ideology (grounding	and	essence;	objectual, generic, and factual identity)	by	at least	two.12 10	For	defense	and	applications	of	the	non-substitutional	take	on	this	apparatus	that	we	prefer, see	e.g.	Dunaway	(2013),	Prior	(1971,	ch.	3),	Rayo	&	Yablo	(2001),	Williamson	(2003),	and	Wright (2007);	also	cf.	Dorr	(2016,	pp.	49-50)	for	discussion	of	these	resources	in	the	context	of	generalized	identity. 11	There's	also	a	more	theoretical	case	to	be	made	(but	to	reiterate,	its	prospects	do	not	affect our	main	aim).	Suppose	that	interanalyzability	among	a	cluster	of	primitives	is	strong	evidence they	fall	under	the	same	kind	(cf.	Cowling	2013,	p.	3900	for	a	somewhat	similar	view).	Then	one may reasonably argue the condition is	met	by analyzing the	objectual "a =	b"	with "a" and "b" proper	names	as	the	generic	"x	is	a	ox	x	is	b"	(cf.	Rayo	2013,	p.	69),	analyzing	the	generic	"p	ox,	y,	... q"	as	the	factual	"£"x"y...(p	o	q)",	and	analyzing	the	factual	"p	o	q"	as	the	generic	"x	is	such	that	p ox	x	is	such	that	q". 12	Modulo	the	issue	of	whether	the	higher-order	quantificational	resources	we	help	ourselves	to must	be	treated	as	primitive	ideology	as	well.	Our	own	view	is	that	one	ought	to	do	so	regardless, but	lack	the	space	to	defend	that	view	here	(but	see	the	work	cited	in	fn.	10). 10 2. Essence	in	terms	of	generalized	identity Philosophers	traditionally	speak	of	essence	when	speaking	of	the	very	'nature'	of some	phenomenon	(or	'what	it	is')	rather	than	how	that	phenomenon	'incidentally'	happens	to	be.	Like	Fine	(1994)	and	many	others,	we	deny	that	what's	essential to	phenomenon is	merely	what	holds	of it	necessarily; and	more	generally,	we deny	that	the	broadly	Aristotelian	notion	of	essence	at	issue	here	is	analyzable	in purely	modal	terms	(see	e.g.	Robertson	&	Atkins	2016	for	a	general	overview).	Yet essence	is	said	in	many	ways;	to	properly	set	up	our	account,	a	couple	preliminaries	about	its	varieties	need	introduction. We	concentrate	on	essentialist	statements	falling	under	three	broad	categories: objectual,	generic,	and	factual	(cf.	Correia	2006;	2013,	who	uses	"alethic"	instead of	"factual").	Examples	include	(12),	(13),	and	(14)	respectively: (12) It's	essential	to	Socrates	to	be	a	human. (13) It's	essential	to	being	a	human	to	be	a	rational	animal. (14) It's	essential	to	Socrates's	being	a	human	that	he	be	a	rational	animal. To	keep	matters	manageable,	among	the	generic	statements,	we	focus	on	monadic cases	like	(13)	(the	extension	to	relational	cases	is	obvious),	and	in	this	section	we leave	aside	other	essentialist	statements	that	don't	fit	neatly	into	these	three	classes.	Importantly,	in	section	4	we	will	broaden	the	perspective	and	consider	collective	essentialist	statements,	which	will	allow	us	to	highlight	a	pleasing	symmetry between	the	concept	of	essence	and	the	concept	of	grounding.13 It	will	also	be	important	to	distinguish	between	describing	what	such-and-such	is in	full	vs.	at	least	in	part	(cf.	Dasgupta	2015,	pp.	18-20).	A	truth	of	full	essence	must at least specify a necessary and sufficient condition for such-and-such. As it is sometimes	put,	such	truths	'individuate'	their	target,	and	in	the	case	of	objectual 13	We	concentrate	on	essentialist	statements	(in	English)	for	sake	of	perspicuity	and	ease,	though strictly	speaking	our	concern	is	with	whatever	it	is	out	there	in	the	world	(so	to	speak)	these	statements are equipped to report. To avoid distractions regarding how this more metaphysically loaded	way	of	speaking	is	to	be	understood	(e.g.	does	it	require	commitment	to	entities	of	some sort,	or	would	a	more	deflationary	approach	suffice?),	we	prefer	to	speak	in	the	first	way,	but	one is	free	to	translate	our	discussion	if	one	wishes. 11 essence	must	specify	an	'individual	essence'	of	the	object	in	question.	So	understood,	our	use	of	"full"	is	tolerant	of	multiple	truths	of	full	essence:	(13),	for	instance,	might	state	the	full	essence	of	being	a	human	even	if	it's	also	fully	essential to	being	human	to	have	a	certain	genetic	makeup/evolutionary	lineage.	Truths	of partial essence	need only specify	what's	necessary for such-and-such. So	while every	truth	of	full	essence	is	(trivially)	a	truth	of	partial	essence,	given	that	there can	be	humans	besides	Socrates,	(12)	is	charitably	read	as	a	truth	of	the	second sort	but	not	the	first. Preliminaries	in	tow,	again	consider	(13).	We	claim	that	(13)	just	is	a	statement	of generalized	identity:	it	truly	characterizes	what	being	human	is	in	full	(generic	essence)	iff	this	is, in	fact,	what	being	human is	(generic	identity).	More	generally (again,	we	stick	to	the	monadic	case): FULL-GENERIC-ESSENCE Being	F	is	what	it	is	to	be	G	in	full	iff:	for	a	thing	to be	G	is	for	it	to	be	F	(in	symbols:	Gx	ox	Fx). We	offer	FULL-GENERIC-ESSENCE	as	itself	a	generalized	identity,	and	use	"iff:"	for	the sake	of	readability.	We	make	no	commitment,	however,	on	whether	the	right-hand side	of	FULL-GENERIC-ESSENCE	expresses	what	philosophers	'meant	all	along'	when speaking	of	full	essence	(recall,	generalized	identity	tolerates	representational	differences	between	the	flanking	expressions).	That	said,	we	offer	it	not	merely	as	a stipulative	definition	of	some	special-purpose	technical	notion.	After	all,	FULL-GENERIC-ESSENCE	self-applies:	its	truth	requires	that	it	itself	state	what	full	essence	is in	full	(in	the	tolerant	sense	of	"full").	We	take	it	that	philosophers	grasp	at	least some	essential	truths	about	full	essence,	and	on	this	basis	can	grasp	certain	core applications of the notion about which there's widespread (albeit imperfect) agreement.	We	thus	accept	the	burden	of	showing	that	FULL-GENERIC-ESSENCE	comports	with	these	core	applications	to	a	high	degree	(and	similarly	for	further	components	of	the	account	to	come). Statements	of	partial	essence	are,	in	contrast,	statements	of	generalized	identity that	are	partial	in	a	certain	sense:	being	an	animal	is	part	of	what	being	human	is 12 (generic	essence)	iff	this	is,	in	fact,	what	being	a	human	partially	is	(generic	identity).	More	generally: PARTIAL-GENERIC-ESSENCE Being	F is	partially	what	it is	to	be	G iff:	there	is some	H	such	that	for	a	thing	to	be	G	is	for	it	to	be both	F	and	H	(in	symbols:	Gx	ox	Fx	Ù	Hx). The	relevant	sense	of	partial	identity	is	tied	to	conjunction.	Suppose	(13)	is	true; then	being	rational,	and	being	an	animal,	are	what	we'll	call	conjunctive	parts	of being	a	human.	(Talk	of	conjunctive	parthood	shouldn't	be	read	as	concerning	a proper	relation	of	part	to	whole,	though	we'll	continue	to	talk	loosely.) Why	believe	that	FULL/PARTIAL-GENERIC-ESSENCE	are	true?	In	part	because	treating them	as	such	sheds	light	on	how	grounding	and	essence	relate	in	ways	illustrated later.	Yet	there	are	also	considerations	speaking	favor	of	them	in	their	own	right. One	is	that	philosophers	routinely	characterize	essence	as	if	it's	intimately	linked to	non-objectual	identity,	in	at	least	two	ways.	First,	"To	be	F	..."	statements	are often	introduced	as	generic	essence	statements,	then	assumed	to	at	least	entail	an objectual	identity	involving	the	property	being	F	(see	e.g.	King	1998,	p.	157	and	fn. 26;	Kment	2014,	p.	153-5;	Koslicki	2012,	pp.	197-201;	Wedgwood	2007,	pp.	1389).	But	this	runs	into	difficulties	like	those	we	raised	at	the	onset.	What	is	it	to	be a	non-self-instantiator?	It's,	in	part,	to	be	something	that	doesn't	instantiate	itself. Yet	there's	no	property	being	a	non-self-instantiator	(cf.	Correia	2006,	pp.	760-3 for	this	and	further	arguments).	Treating	essence	as	also	linked	to	non-objectual identity	via	PARTIAL-GENERIC-ESSENCE	evades	the	problem	while	still	linking	"To	be F	..."	to	statements	of	identity. Second,	when	discussing	objectual	essence,	philosophers routinely	use	phrases like	"a	thing's	essence"	interchangeably	with	phrases	like	"the	identity	of	a	thing" (see	e.g.	Fine	1994,	p.	3;	Lowe	2008,	p.	37;	Shalkowski	2008,	p.	37).	However,	an objectual	reading	renders	this	link	mysterious.	To	speak	of	a	thing's	identity	in	the sense	of	essence	isn't	merely	to	report	the	triviality	that	it's	self-identical	(Lowe ibid.),	nor	that	there	are	non-trivial	necessary	and	sufficient	conditions	for	being identical	to	it:	only	some	such	conditions	describe	what's	essential	to	the	thing	at 13 issue	(as	straightforward	modifications	of	Fine's	famous	examples	have	taught	us: 1994,	pp.	4-5).	Essence	and	identity	link	together	perfectly,	though,	if	one	brings in	non-objectual	notions	of	both.	Following	Correia	(2006,	pp.	764-5)	we	account for	objectual	essence	in	terms	of	generic	essence: FULL-OBJECTUAL-ESSENCE Being	F	is	what	x	is	in	full	iff:	being	F	is	what	it	is to	be	x. PARTIAL-OBJECTUAL-ESSENCE Being	F is	what	x is in	part iff:	being	F is	part	of what	it	is	to	be	x. PARTIAL-OBJECTUAL-ESSENCE	and	PARTIAL-GENERIC-ESSENCE	together	yield	an	account of	partial	objectual	essence	in	terms	of	generalized	identity:	a	statement	like	(12) truly	describes	part	of	what	Socrates	is	(objectual	essence)	just	in	case	it	truly	describes	what	being	Socrates	partially	is	(generic	identity).	And	similarly	for	FULLGENERIC-ESSENCE	and	FULL-OBJECTUAL-ESSENCE. The	account	can	also	be	extended	to	factual	essence: FULL-FACTUAL-ESSENCE Its	being	the	case	that	p	is	what	it	is	for	it	to	be	the case	that	q	in	full	iff:	for	it	to	be	the	case	that	q	is for	it	to	be	the	case	that	p	(in	symbols:	q	o	p). PARTIAL-FACTUAL-ESSENCE Its	being	the	case	that	p	is	in	part	what	it	is	for	it to	be	the	case	that	q	iff:	there	is	some	r	such	that for	a	thing	to	be	q	is	for	it	to	be	the	case	that	both p	and	r	(in	symbols:	q	o	p	Ù	r). We've	noted	a	few	core	applications	of	essence	our	account	accommodates,	but the	case	for	extensional	adequacy	extends	well	beyond	these	(we	continue	to	focus	on	monadic	generic	essence,	but	what	we	say	below	generalizes). To	illustrate,	compare	our	account	with	one	proposed	by	Rayo	(2013,	pp.	122-3), which	takes	roughly	the	form	of	the	above,	yet	takes	mutual	necessitation	to	be necessary	and	sufficient	for	generalized	identity.	Since	being	F	is	necessary	for	being a particular thing,	a, iff being a	mutually necessitates being	a and	being	F, Rayo's	account	entails	that	it	is	essential	to	a	that	it	is	F	iff	being	F	is	necessary	for being	a.	Rayo's	account	is	thus	ill-suited	to	capture	the	broadly	Aristotelian	notion 14 of	objectual	essence	we	aim	to	capture	(as,	again,	Fine's	famous	cases	have	taught us).14	Moreover,	if	mutual	necessitation	sufficed	for	generic	identity,	the	following would	universally	hold: (15) Fx	ox	Fx	Ù	(Fx	Ú	Gx) (16) Fx	ox	Fx	Ù	(Gx	Ú	¬Gx) These	are	generic	versions	of	principles	A12	and	A14,	respectively,	mentioned	in section	1.	We	denied	A12	and	A14	the	status	of	logical	validities,	and	do	the	same with	(15)	and	(16):	clearly,	to	be	a	number	isn't	the	same	as	being	a	number	and either-a-number-or-blue,	nor	is	it	the	same	as	being	a	number	and	either-blue-ornot-blue	(recall	our	earlier	discussion	of	"grue"	and	"bleen").	We	reject	that	mutual necessitation suffices for generic identity, evading seemingly false consequences that (15)–(16)	would	have if fed through	PARTIAL-GENERIC-ESSENCE: that being	a	number	is	essentially	linked	to	being	blue.15 PARTIAL-GENERIC-ESSENCE	also	looks	extensionally	adequate	in	cases	where	being	F is	a	genus	(i.e.	being	an	animal),	with	being	G	a	species	of	that	genus	(i.e.	being human).	In	these	cases,	a	differentia	of	the	genus	(i.e.	being	rational)	serves	as	the 'supplementary'	H	in	PARTIAL-GENERIC-ESSENCE,	and	genus	and	differentia	turn	out essential	to	the	species,	as	desired.	But	other	cases	may	raise	doubts.	For	instance, if	having	a	mass	is	part	of	what	it	is	to	be	an	apple,	it's	hard	to	see	which	supplementary	H	could	be	such	that	to	be	an	apple	is	to	have	a	mass	and	to	be	H. Though	this	objection	is	natural,	we	can	offer	a	remarkably	simple	proof	that	the biconditional	corresponding	to	PARTIAL-GENERIC-ESSENCE	is	correct.	Let	"Fx	⊆x	Gx" abbreviate	"Being	F	is	part	of	what	it	is	to	be	G"	(to	preview	notation	introduced later).	The	proof	relies	on	the	following	general	principles	about	generic	identity, partial	generic	essence,	and	their	interaction: 14	Rayo	is	well	aware	of	this	(2013,	p.	122).	But	like	we	said	in	fn.	8,	certain	contentious	theses serve	as	backdrop	for	his	discussion	that	we	cannot	evaluate	here	(but	cf.	Rayo	2016,	pp.	17-21	for further	discussion	of	his	views	on	essence,	which	differs	somewhat	from	his	2013). 15	The	account	of	grounding	that	emerges	in	section	3	provides	a	further	way	to	argue	that	our account	evades	these	consequences	of	Rayo's	account:	see	the	end	of	section	4. 15 (i) ox	is	symmetric (ii) Fx	ox	Fx	Ù	Fx idempotence	of	Ù (iii) Fx	⊆x	Gx	Ù	Fx Ù-intro	I (iv) Fx	⊆x	Fx	Ù	Gx Ù-intro	II (v) If	Fx	⊆x	Gx,	then	Fx	Ù	Hx	⊆x	Gx	Ù	Hx Ù-adjunction	for	⊆ (vi) If	Fx	⊆x	Gx	and	Gx	ox	Hx,	then	Fx	⊆x	Hx substitution (vii) If	Fx	⊆x	Gx,	and	Gx	⊆x	Fx,	then	Fx	ox	Gx antisymmetry And	here's	the	proof: Left-to-right.	Suppose	Fx	⊆x	Gx.	Then	by	(v),	Fx	Ù	Gx	⊆x	Gx	Ù	Gx.	By	(i), (ii)	and	(vi),	it	follows	that	Fx	Ù	Gx	⊆x	Gx.	From	this,	plus	(iii)	and	(vii), infer	that	Gx	ox	Fx	Ù	Gx.	Hence,	for	some	H,	Gx	ox	Fx	Ù	Hx. Right-to-left.	Suppose for	a	given	H that	Gx	ox	Fx	Ù	Hx.	Then	by	(i), it follows	that	Fx	Ù	Hx	ox	Gx.	By	(iv)	and	(vi),	infer	Fx	⊆x	Gx. The	proof	is	remarkable	in	its	simplicity,	but	also	(we	take	it)	by	the	plausibility	of the principles it assumes. (i) and (ii) are compulsory principles about generic identity,	and	counterparts	of	principles	about	factual	identity	advocated	earlier. (iii)-(v)	are	analytic-sounding	principles	about	partial	generic	essence.	(vi)	is	an instance	of	Leibniz's	Law	for	o	(see	section	1).	We	assume	in	effect	that	the	context "Fx	⊆x	..."	is	transparent	for	generic	identity	(surely,	for	instance,	if	being	an	animal	is	part	of	what	it	is	to	be	a	human	being,	then	given	that	to	be	a	human	being is	to	be	a	Homo	sapiens,	being	an	animal	is	part	of	what	it	is	to	be	a	Homo	sapiens). And	(vii) looks	compelling	provided	that	"partial" in	"partial	essence" is	understood	in	the	liberal	sense	discussed	before. The	above	reasoning	also	gives	a	direct	reply	to	the	objection	put	forward	above. The	objection	was	that	there	appears	to	be	no	H	such	that	to	be	an	apple	is	to	have a	mass	and	to	have	H	(although	of	course	the	worry	generalizes).	The	left-to-right direction	of	the	proof	above	provides	us	with	such	a	feature:	being	an	apple.	The 16 objection	initially	looked	compelling,	we	think,	due	to	assuming	that	H	must	be proper	conjunctive	part	of	being	an	apple.	As	should	be	plain	at	this	point,	no	such reading	of	PARTIAL-GENERIC-ESSENCE	is	intended.16 But	what	of	the	intimate	link	widely	thought	to	hold	between	essence	and 'real definition'?	Our	account	entails	that	partial	generic	essence	is	reflexive	(since	for a	thing	to	be	F	is	for	it	to	be	F	Ù	F	by	(ii)	from	the	proof	above),	and	that	full	generic essence	is	reflexive	and	symmetric	(since	ox	is	reflexive	and	symmetric).	On	one hand,	these	consequences	seem	undeniable.	If	anything	is	essential	to	being	human,	it	is	being	human;	and	we	find	it	hard	to	fathom	why	being	human	would	fail to	be	what	it is	to	be	a	rational	animal, if	one	accepts	the	reverse.	On	the	other hand,	one	might	complain	that	essentialist	statements	no	longer	supply	real	definitions,	since	real	definitions-at	least	given	a	traditional	conception	that	models them	after	reductive	analyses-cannot	be	circular	in	either	way. There	are	in	fact	two	objections	to	consider:	one	turns	on	a	merely	verbal	matter, while	the	other	is	substantive.	But	first	of	all,	what	is	a	real	definition?	We	adopt the	more	or less	standard	view	that takes it to	be	a	truth	of	a	certain	sort,	one that-in	the	case	of	(13)-characterizes	not	what	the	word	"human"	happens	to mean	in	English	(which	is	the	purview	of	a	nominal	definition),	but	rather	what being	a	human	is 'in	itself'	(see	e.g.	Fine	1994;	Kment	2014,	pp.	158-9;	Koslicki 2012,	pp.	190,	197-201;	Lowe	2012,	pp.	104-5;	Rosen	2010,	p.	122;	2015).	On	our view,	only	some	true	"To	be	F	is	..."	statements	express	real	definitions.	And	distinguishing	those	that	do	arguably	only	requires	appealing	to	notions	that	are	analyzable	in	terms	of	generalized	identity,	or	that	are	plainly	not	essentialist	(e.g. the	truth-functional	connectives).	Since	real	definitions	are	expressed	by	a	proper subset	of	true	essentialist	statements,	we	handle	the	more	substantive	challenge: to	link	essence	and	real	definition	in	an	intimate	way.17	But	suppose	one	insists	on 16	To	be	clear:	we	are	not	denying	that	conjunctive	parthood	obeys	something	like	the	classical mereological principle of	weak supplementation (thanks to a referee for pressing us to clarify here).	Rather,	what	we	say	here	is	that	it is	hard	to	see	what	the	supplemental	conjunctive	part would	be	in	cases	like	the	one	at	hand,	which	is	of	course	compatible	with	there	in	fact	being	one. Whether	conjunctive	parthood	obeys	this	(or	some	other)	supplementation	principle	is	a	substantive	question	that	we	hope	to	address	in	future	work. 17	We're	not	denying	that	philosophers	can	(and	do)	communicate	real	definitions	using	statements	making	no	explicit	mention	of	essence	(e.g.	necessitated	universal	biconditionals),	nor	that 17 a	more	intimate	link:	i.e.	that	every	truth	of	essence	must	express	a	real	definition, if	only	a	partial	one.	We	demur,	but	the	'dispute'	here	strikes	us	as	merely	verbal. Those	who	insist	on	using	"real	definition"	in	this	fashion	could	read	our	account as	implicitly	defining	the	notion	of	proto-essence,	and	then	let	us	analyze	(what they	call)	the	notion	of	essence	in	a	fashion	exactly	analogous	to	what	we	suggest below. Now,	there	is	no	consensus-and	considerable	imprecision-about	what	kind	of truth	a	real	definition	is,	and	specifically	over	whether	a	'reductive	analysis'	type model	is	the	only	viable	one	(e.g.	Rosen	argues	that	recursive	definitions	can	be real	definitions:	2015,	pp.	196-7).	We	certainly	don't	wish	to	take	a	stance	on	the matter	here.	Nor	will	we	attempt	to	survey	how	our	account	stacks	up	to	certain more	precise	proposals	in	the	literature	(though	we	hope	to	do	so	in	the	future). Our	goal	here	is	modest:	to	challenge	the	impression	that	there	is	some	obstacle in	principle,	and	on	the	assumption	that	real	definitions	must	be	non-circular. Start	with	merely	partial	real	definition	and	let	(12)	be	our	stock	example.	If	our account is	correct, the	truth	of	(12)	requires	that	being	human	is	a	conjunctive part	of	being	Socrates.	One	obvious	way	to	go is to further	require	of	(12)	that being	Socrates	isn't	itself	a	conjunctive	part	of	being	human.	Since	conjunctive	parthood	is	antisymmetric,	this	amounts	to	requiring	that	being	Socrates	and	being human	not	be	generically	identical-and	they	clearly	aren't.	More	generally,	requiring	that	conjunctive	parthood	hold	asymmetrically	in	a	case	of	merely	partial real	definition	gives	substance	to	the	idea	that	the	definiens	cannot	itself	be	'built up'	from	the	definiendum;	and	to	the	idea	that	the	latter	cannot	be	a	part	of	the essence	of	the	former,	given	that	not	being	a	conjunctive	part	of	such-and-such entails	not	being	part	of	its	essence.	(An	even	more	demanding	condition	along these	lines	uses	the	notion	of	disjunctive	parthood	that	we	analyze	in	terms	of	gen- philosophers	use	"real	definition"	to	refer	to	whatever	the	definiens	phrase	contributes	to	the	truth of	the	relevant	sort	of	essentialist	statement,	rather	than	to	the	truth	as	a	whole.	The	conditions we	consider	for	an	essentialist	statement	to	express	(what	we	call)	a	real	definition	can	be	tweaked in	obvious	ways	to	comport	with	these	broader	uses	of	the	phrase. 18 eralized	identity	in	section	3,	and	requires	that	the	definiendum	be	neither	a	conjunctive	part,	nor	a	disjunctive	part,	nor	either	a	conjunctive	or	disjunctive	part	of any	conjunctive	or	disjunctive	part,	or	...	of	the	definiens). Full	real	definition-let	(13)	be	the	stock	example-requires	separate	treatment. The first	option	will	not	do,	of	course,	since	(13) is	a	generic identity,	and	thus being	human	is	a	conjunctive	part	of	being	a	rational	animal	and	vice	versa.	Nor can	we	say	that	(13)	expresses	a	real	definition	only	if	being	human	is	grounded in	being	a	rational	animal,	given	the	standard	assumption	that	nothing	grounds itself.	This	observation	has	led	some	to	doubt	that	generic	identity	could	be	used to	state	what	a	full	real	definition	is,	given	that	the	latter	has	a	built-in	priorityindicating	directionality	(cf.	Cameron	2014,	pp.	429;	Fine	2015,	pp.	308).	But	even if	the	two	notions	should	not	be	identified	(which	we	readily	concede),	it	may	well be	that	the	second	can	be	analyzed	partially	in	terms	of	the	first,	perhaps	with	the aid	of	further	non-essentialist	notions. One	approach-a	fairly	traditional	one-stems	from	the	thought	that	a	"To	be	F	is to	be	G"	statement	expresses	a	real	definition	only if it takes	a	certain form.	At minimum,	the	definiendum	phrase	must	be	different	from	the	one	expressing	the definiens;	but	since	this	would	not	rule	out	pathological	cases	like	"To	be	F	is	to	be both	F	and	F",	more	must	be	said.	Often,	further	constraints	are	placed	on	the	constituent	expressions	from	which	the	definiens	expression	is	built.	We	cannot	appraise	every	such	constraint	that	has	been	suggested	here	(see	e.g.	King	1998	and Koslicki	2012	for	just	a	couple).	But	one	can	imagine	various	constraints	of	this sort	that	are	amenable	to	our	account.	One	is	to	require	that	whatever	is	expressed by	some	proper	constituent	of	the	definiens	phrase	not	have	what	is	expressed	by the	definiendum	phrase	as	a	conjunctive	part.	Not	only	does	(13)	seem	to	meet this	test,	but	as	before	this	proposal	gives	substance	to	idea	that	the	definiens	cannot	itself	be	'built	up'	from	the	definiendum,	and	that	the	latter	cannot	be	part	of the	essence	of	the	former.	(Although	again,	perhaps	the	more	demanding	condition	we	mentioned	before	is	preferable.) In	floating	these	tentative	proposals	about	how	to	sift	out	essentialist	statements that	express	real	definitions	from	those	that	do	not,	let	us	be	clear:	we	have	not 19 surveyed	whether	they	comport	with	all	the	nebulous	ways	"real	definition"	gets used	in	philosophical	parlance,	and	there	are	no	doubt	other	viable	proposals	to explore	than	the	two	offered.18	What	we	have	shown	is	that	our	critic	must	explain why	these	proposals	(or	some	extension	thereof)	are	not	up	to	the	task. If	one	agrees	that	the	account	of	essence	we've	offered	is	extensionally	adequate, one	might	finally	wonder	whether	it	is	suitably	'reductive'.	The	case	is	mixed.	On one	hand,	some	who	partake	in	"To	be	F	is	..."	talk	are	skeptical	of	broadly	Aristotelian	notions	of	essence	(cf.	Rayo	2013,	p.	5;	2015a).	On	the	other,	others	attempting	to	communicate	the	relevant	notions	of	essence	treat	"To	be	F	is	..."	talk	as	a representative	form	of	expression.	Our	own	opinions	diverge	on	the	issue;	but	the important	point	is	that	even	a	non-reductive	approach	is	faithful	to	our	aims.	Ideological	economy	is	preserved,	as	we	ultimately	analyze	grounding	with	"To	be	F is	..."	talk:	if	such	talk	is	essentialist,	one	still	trades	two	primitive	ideological	kinds (grounding	and	essence)	for	one.	And	even	then,	analyzing	grounding	in	terms	of such	talk	is	a	noteworthy	way	to	unify	the	two	indeed.	So	let's	set	aside	whether such	talk	is	essentialist,	and	turn	to	the	fruits	of	unification	we	can	gain	from	it. 3. Grounding	in	terms	of	generalized	identity Philosophers	traditionally	speak	of	grounding	when	they	say	that	such-and-such in	some	sense	'makes'	or	'brings	about'	so-and-so,	in	a	constitutive	rather	than	a causal	sense	that	is	unanalyzable	in	purely	modal	terms	(see	e.g.	Bliss	&	Trogdon 2014	for	a	general	overview).	Begin	with	factual	grounding,	as	it's	more	familiar (generic	grounding,	which	is	less	familiar,	is	left	for	later).	We	express	the	notion with	statements	like Its	being	the	case	that	p1,	p2,	...	makes	it	the	case	that	q; we	write	them	with	Fine's	(2012)	familiar	'<'	symbol	for	strict	full	grounding	as: p1,	p2,	...	< q. 18	Correia	(forthcoming)	and	Skiles	(2014,	pp.	225-230)	sketch	accounts	of	full	real	definition	on the	model	of	reductive	analysis	utilizing	notions	of	grounding. 20 For	sake	of	ease,	we	will	often	speak in 'predicationalist' terms	as if	grounding were	a	relation	between facts	referred to	by these	Greek letters,	but	merely	as shorthand	for	the	'operationalist'	reading	above	(cf.	Correia	2010,	pp.	253-254). We	analyzed	partial	essence,	recall,	in	terms	of	conjunctive	parthood,	which	was defined	in	terms	of	generalized	identity.	We	now	propose	to	analyze	grounding	in terms	of	another	parthood	relation-disjunctive	parthood-which	we	analyze	in an	analogous	fashion,	invoking	disjunction	instead	of	conjunction.	Say	that	p	is	a disjunctive	part	of	q	(in	symbols:	p	⊑∨	q)	iff:	for	some	r,	for	q	to	hold	is	for	p Ú r	to hold.	(So,	for	instance,	the	ball's	being	red	is	a	disjunctive	part	of	its	being	eitherred-or-round.) Strictly speaking,	we analyze grounding in terms of disjunctive parthood,	together	with	a	'hybrid'	notion	which	is	itself	defined	in	terms	of	disjunctive	parthood.	Say	that	p	is	a	conjunctive	part	of	a	disjunctive	part	of	q	(in	symbols:	p	⊑∧∨	q)	iff:	there's	some	r such	that p	Ù	r	⊑∨	q.	(So,	for	instance,	the	ball's being red stands in this hybrid relation to being either both-red-and-round	or blue.) We	claim	that	a	collection	of	facts	p1,	p2,	...	grounds	another	fact	q iff	conjoining	p1, p2,	...	gives	you	a	disjunctive	part	of	q (thus	each	of	p1,	p2,	...	is	a	conjunctive	part of	a	disjunctive	part	of	q),	yet	there's	no	way	of	conjoining	facts	with	q	that	gives you	a	disjunctive	part	of	any	of	p1,	p2,	...	(thus	q is	not	a	conjunctive	part	of	any disjunctive	part	of	the	facts	in	that	collection).	In	symbols: FACTUAL-GROUNDING p1,	p2,	...	<	q	iff:	(i)	p1	Ù	p2	Ù	... ⊑∨	q;	and	(ii)	neither	q	⊑∧∨	p1,	nor	q	⊑∧∨	p2,	nor	... A	concrete	example	to	illustrate:	take	the	highly	plausible	claim	that	a's	being	red (p1)	and	a's	being	round	(p2)	jointly	ground	their	conjunction	(q).	Since	for	q	to hold	is	for	q	Ú	q	to	hold	(by	axiom	A3	of	the	system	GI	from	section	1),	the	first condition	is	met,	as	desired.	And	so	long	as	q	is	not	itself	a	conjunctive	part	of	a disjunctive	part	of	either	p1	and	p2	in	turn-an	assumption	that's	eminently	reasonable,	but	that	we	put	on	firmer	footing	shortly-the	second	condition	is	met. Hence,	FACTUAL-GROUNDING	gets	the	right	result. 21 It's not surprising that FACTUAL-GROUNDING handles this 'tailor-made' example. What's	surprising	is	that	there's	good	reason	to	believe	it	handles	even	the	less obvious	cases.	But	first,	a	couple	clarifications. First	clarification:	note	that	FACTUAL-GROUNDING	employs	the	non-factive	notion	of generalized	identity.	Thus	it	characterizes	a	non-factive	notion	of	grounding:	it's not	required	that	p1,	p2,	...,	and	q all	hold	for	p1,	p2,	...	to	ground	q (cf.	Fine	2012, pp.	48-50).	A	factive	analogue	can	be	wrought	by	adding	a	factivity	condition:	i.e., that	p1,	p2,	...	all	hold.	(We'll	continue	to	work	with	the	simpler	non-factive	account above,	although	the	following	discussion	won't	turn	on	it.) Second	clarification:	given	that	generalized	identity	is	symmetric	and	transitive, and	that	the	rules	R3	and	R4	are	truth-preserving,	FACTUAL-GROUNDING	entails	that ground-theoretic	status	is	preserved	under	factual	identity.	More	precisely: (17) a. If	p,	p1,	p2	... ground	q	and	p	o	p*	,	then	p*,	p1,	p2,	...	ground	q. b. If	p1,	p2,	... ground	q	and	q	o	q*,	then	p1,	p2,	...	ground	q*. FACTUAL-GROUNDING	thus	captures	a	worldly	conception	of	grounding	in	the	sense of	Correia	(2010,	pp.	256-259)-albeit	with	the	merely	cosmetic	difference	that Correia	there	uses	the	term	"factual	equivalence",	and	the	more	substantive	difference	that	we	have	adopted	the	successor	logic	of	Correia	(2016),	i.e.	the	system GI. This substantially impacts how FACTUAL-GROUNDING should be understood, which	is	clearly	visible	in	logical	cases.	p	is	arguably	factually	identical	to	p	Ú	p,	to p	Ù	p,	and	to	¬¬p,	differing	not	in	the	way	the	world	is	represented	as	being,	but rather	how	they	represent	the	world	as	being	that	way	(as	Fine	puts	it:	forthcoming, pp. 10-1). Yet if grounding is irreflexive, FACTUAL-GROUNDING entails that p doesn't	ground	these 'other' facts. In	contrast,	a	conception	of	grounding that's representational ("conceptual" is the term used in Correia 2010) requires that ground-theoretic	status	only	be	preserved	under	some	more	representation-sensitive	notion	of	equivalence,	which	may	distinguish	p	from	p	Ú	p,	p	Ù	p,	and	¬¬p. That	FACTUAL-GROUNDING	applies	only	to	worldly	grounding	doesn't	diminish	its	interest,	we	think,	as	the	primary	metaphysical	interest	in	grounding	concerns	how 22 it	structures	the	world	itself,	independently	of	how	we	think	or	talk	about	it	(cf. Correia	2010,	pp.	258-9;	Krämer	&	Roski	2015,	pp.	60-1). Seen	in	this	light,	FACTUAL-GROUNDING	is	in	a	sense	not	completely	new:	the	system for	the	logic	of	worldly	grounding	that	Correia	(2010)	develops	has	a	theorem- he	calls	it	the	Reduction	Theorem-that	is	just	a	factivity-requiring	analogue	of	the biconditional	corresponding	to	FACTUAL-GROUNDING.	Yet	he	isn't	happy	with	this	result.	Correia	worries	that	the	first	necessary	condition	imposed	on	grounding	by FACTUAL-GROUNDING-embodied	in	what	he	calls	the	Reduction	Axiom-entails	that whatever is grounded "has a disjunctive nature", and that "grounding always arises	via	disjunction",	which	he	takes	to	be	implausible	in	general:	"although	one can	maintain	[...]	that	the	fact	that	{Socrates}	exists	is	grounded	in	the	fact	that Socrates	exists,	the	view	that	the	former	fact	is	the	disjunction	of	the	latter	fact and	another	fact	is	implausible"	(ibid.,	p.	272). There	are	a	number	of	worries	that	could	be	lurking	in	the	background	here.	And even	setting	those	aside,	to	the	extent	one	has	intuitions	about	what	is	(and	isn't) a 'disjunctive	part' or a 'conjunctive	part of a	disjunctive	part' of	what, they're weak	indeed;	thus	it's	hard	to	see	how	to	motivate	our	account.	Let's	change	tack by	taking	an	indirect	route	from	grounding	to	generalized	identity:	by	analyzing the	first	in	terms	of	the	second	by	means	of	a	more	intuitive	notion	we	call	subsumption.	By	making	use	of	subsumption-which	many	will	find	easier	to	grasp, and	already	plays	a	notable	role	in	recent	literature	on	grounding-we	can	more easily	fend	off	worries	with	our	account,	and	also	provide	reasons	to	accept	it. 3.1 The	notion	of	subsumption Subsumption	comes	in	a	generic	as	well	as	in	a	factual	variant-the	latter	will	be used	for	factual	grounding,	and	the	former	for	a	generic	notion	of	grounding	that we	introduce	later.	Although	generic	grounding	is	less	familiar,	generic	subsumption	is	intuitively	easier	to	grasp	and	so	we	focus	on	it	first. To	start	with,	consider	a	broader	notion	that	subsumes	(in	the	ordinary	sense	of the	term)	subsumption.	Suppose	that	to	be	a	human	is	be	a	rational	animal.	Then we	take	it	that	there's	an	intuitively	natural	sense	in	which	one	could	then	infer 23 that	being	human	is	a	way	(or	manner)	of	being	an	animal-a	different	way	than, say,	being	a	cat.	This	link	between	conjunctive	parthood	and	"is	a	way	of"	talk	is not	incidental,	as	it	readily	generalizes	beyond	species-genus	cases:	one	can	say, for	instance,	that	being	Socrates	is	a	way	of	being	a	human	(if	being	human	is	a conjunctive	part	of	being	Socrates),	that	being	red	and	round	is	a	way	of	being	red, and	so	on. Importantly,	this	use	of	"is	a	way	of"	talk	readily	contrasts	with	causal	readings	of this idiom-expressed	when	one	says, for instance, that traveling	westward	on the	Hume	Highway	is	a	way	of	getting	to	Melbourne.	Traveling	westward	on	the Hume	Highway	could-in	the	metaphysical	sense-have	failed	to	be	a	way	of	getting to	Melbourne,	while being red and round could not-in this sense-have failed	to	be	a	way	of	being	red. We	take	any	case	of	subsumption,	like	any	case	of	conjunctive	parthood,	to	be	a case	of	being-a-way-of	in	the	non-causal	sense	intended	here.	Instances	of	the	determinate-determinable	relation	yield	archetypical	cases	of	subsumption:	if	being F	(e.g.	being	red)	is	a	determinate	of	being	G	(e.g.	being	colored),	then	we	take	F	to be	subsumed	by	G,	and	(thus)	take	being	F	to	be	a	way	for	a	thing	to	be	G.	Nonetheless,	what	holds	for	the	determinate-determinable	relation	need	not	hold	for subsumption	more generally. First, a determinable property is always distinct from	each	determinate	(by	"distinct",	we	mean	non-identical	in	the	sense	of	generalized	identity):	being	colored,	e.g.,	is	distinct	from	being	red.	Yet	one	should	not take	this	as	evidence	that	subsumption	is	irreflexive,	since	being	F	(trivially)	subsumes	being	F.	Second,	the	determinates	of	a	determinable	property	are	typically many	in	number,	and	some	of	them	may	well	be	mutually	incompatible:	thus	being red	and	being	blue	are	both	subsumed	by	being	colored,	and	no	single	thing	could be	both.	Yet,	again,	one	should	not	take	this	as	evidence	that	there	will	always	be several	incompatible	ways	subsumed	by	being	so-and-so,	provided	that	there	is	at least	one.	For	instance,	we	take	it	that	being	Socrates	is	subsumed	by	being	a	member	of	{Socrates},	yet	presumably	there	is	no	further,	incompatible	way	of	being	a member	of	{Socrates}	than	being	Socrates. We	also	don't identify	subsumption	with	being-a-way-of itself, as the former is 24 systematically	connected	to	grounding	in	ways	that	the	latter	isn't.	It	is	natural, and	standard,	to	assume	that	what	serves	as	a	ground	must	be	wholly	relevant	(or contain	no	part	that	is	irrelevant)	to	what	it	grounds	(cf.	Dasgupta	2014,	pp.	4-5; Litland	2016,	p.	534).	This	is	not	always	the	case	for	beinga-way-of: it is	clear enough	that	being	red	and	round	is	not	wholly	relevant	to	being	red.	Yet	determinate-determinable	connections	satisfy	this	constraint:	a	thing's	being	red	is	not only	a	way	of	being	colored,	but	also	wholly	relevant	to	being	colored.	As	we	understand	it,	"subsumption"	stands	for	links	of	being-a-way-of	that	meet	this	relevance	constraint. What	we	said	about	generic	subsumption	we	also	want	to	say,	mutatis	mutandis, about	the	factual	variety.	Examples	of	link	of	factual	subsumption	are	easily	seen on	a	case-by-case	basis	(e.g.	via	the	plausible	thought	that	the	ball's	being	either red	or	blue	subsumes	its	being	red),	and	thanks	to	the	plausible	principle	that	if being	G	subsumes	being	F,	then	for	any	x,	x's	being	G	subsumes	x's	being	F. For	reasons	that	will	soon	become	clear,	we	regiment	statements	of	subsumption with	Fine's	(2012)	"≤"	notation	for	weak	full	grounding,	and	embellish	it	with	a subscript	when	the	statement	is	generic.	Thus	we	write	the	generic	subsumption statement	"Being	red	is	subsumed	by	being	colored"	as	"x	is	red	≤x	x	is	colored" (and	similarly	for	non-monadic	cases),	and	write	statements	of	factual	subsumption	of	the	form Its	being	the	case	that	p is	subsumed	by	its	being	the	case	that	q as p	≤	q. 3.2 Grounding	in	terms	of	generalized	identity	via	subsumption So	what,	exactly,	is	subsumption?	And	what	bearing	does	it	have	on	our	account of	what	grounding	is?	To	the	first	question,	we	will	argue	that	subsumption	is	the converse	of	disjunctive	parthood:	such-and-such's	being	a	wholly	relevant	way	of being	thus-and-so	is	nothing	more	than	the	former	being	a	disjunctive	part	of	the 25 latter.	And	to	the	second	question,	we	will	argue	that	grounding	can	be	analyzed in	terms	of	subsumption	in	a	manner	exactly	analogous	to	how	we	proposed	to analyze	grounding	in	terms	of	disjunctive	parthood.	Let's	take	these	claims	in	reverse	order,	and	as	before	focus	on	factual	grounding	(we	will	introduce	and	analyze	the	generic	notion	in	due	course). We	spoke	earlier	of conjunctive	parts	of	a	disjunctive	part of such-and-such. In analogous	way,	it	is	natural	to	speak	of	conjunctive	parts	of	what's	subsumed	by such-and-such.	For	example:	given	that	being	an	animal	is	a	conjunctive	part	of being	a	human,	which	is	subsumed	by	being	a	living	organism,	being	an	animal bears	this	relation	to	being	a	living	organism.	Say	that	p	is	quasi-subsumed	by	q	(in symbols:	p	≲	q)	iff	there	is	some	r	such	that	p	∧	r	≤	q.	Replacing	⊑∨	with	≤	in	our original	account	of	grounding,	and	⊑∧∨	with	≲,	delivers	the	following	subsumption-theoretic	analogue: (18) p1,	p2,	...	<	q	iff: (i) p1	Ù	p	2	Ù	...	≤	q;	and (ii)	neither	q	≲	p1,	nor	q	≲	p2,	nor	... We are	not the first to offer something akin to (i) as a requirement on factual grounding:	Litland (2013,	pp.	23-25) similarly takes	p1,	p2,	... to	ground	q only when	p1,	p2,	...	"collectively	constitute	a	way for [q] to	be the	case",	and in that sense	"[make]	a	difference	to	how	[q]	obtains",	and	uses	this	condition	to	address putative	counterexamples	to	the	transitivity	of	grounding	due	to	Schaffer	(2012). The	idea	that	(ii)	is	a	further	requirement	can	be	supported	as	follows.	Suppose for	reductio	that	p	<	q,	and	yet	q	≲	p	(cases	with	several	grounds	can	be	treated in	the	same	way).	Then	q	∧	r	≤	p	for	some	given	r,	and	therefore	q	∧	r	<	q	(we	here appeal	to	a	plausible	principle:	if	s1	≤	s2	and	s2	<	s3,	then	s1	<	s3).	Which-we	take it-could	never	be:	conjunctions	don't	ground	any	of	their	conjuncts. Moreover,	there	are	striking	similarities	between	(18)	and	principles	defended	in the	literature	that link	grounding	to	notions	in	the	vicinity	of	subsumption.	For instance,	when	Fine	(2012,	pp.	51-54)	introduces	the	weak	full	grounds	of	a	fact, he	characterizes	them	with	a	"For	... is	for	__"	idiom	that	allows	"__"	to	be	plural, and	that	differ	from	the	fact's	strict	full	grounds	as	they	"may	also	move	us	sideways	in	the	explanatory	hierarchy".	With	this	notion,	Fine	tentatively	proposes	a 26 definition	of	strict	full	grounding	that	is	analogous	to	our	(18): (19) p1,	p2,	... <KF	q	iff (i)	p1	Ù	p2	Ù	...	≤KF	q;	and (ii)	neither	q	≲KF	p1,	nor	q	≲KF	p2,	nor	..., where	<KF	is	used	for	strict	full	grounding,	≤KF	for	weak	full	grounding,	and	≲KF	for weak	partial	grounding	(where	p	≲KF	q	iff	there	is	some	p1,	p2,	...,	r	such	that	p,	p1, p2,	...,	r	≲KF	q).	The	analogy	is	inexact,	since	Fine's	ground-theoretic	notions	are representational	(he	accepts	that	p	<KF	p	Ù	p,	and	that	it's	never	the	case	that	p <KF	p),	while	our	subsumption-theoretic	notions	are	meant	to	be	worldly	(from which	one	can	argue	that	that	p	<	p	Ù	p	never	holds).19	Nonetheless,	the	analogy is	apt:	given	difficulties	with	explicating	what,	exactly,	Fine	has	in	mind	by	weak grounding	(cf.	deRosset	2013),	one	could	reasonably	adopt	our	(18)	as	a	way	of explicating	the	worldly	analogue	of	Fine's	(19). Litland	(2013,	pp.	23-25)	also	offers	an	analogue	of	(18),	instead	employing	the notion	of	(metaphysical)	explanation-how	mentioned	above	(which	he	takes	as primitive).	Say	that	p1,	p2,	...	are	downward-subsumed	by	q	iff,	as	Litland	phrases	it, "any	ways	for	p1,	p2,	...	to	obtain	collectively	constitute	a	way	for	q	to	obtain".	Litland's	principle	can	then	be	formulated	thus: (20) p1,	p2,	...	<JL	q	iff (i) p1,	p2,	... are	downward-subsumed	by	q;	and (ii) there	are	no	r1,	r2,	...	such that	r1,	r2,	...,	q are downward-subsumed	by	some	pi	(i	=	1,	2,	...) Though	Litland	has	a	representational	notion	of	grounding	in	mind,	suppose	we treat	(20)	as	concerning	a	worldly	notion.	Then	the	similarity	to	(18)	isn't	merely formal.	For	it's	natural	to	take	"p1,	p2,	... are	downward-subsumed	by	q"	as	equivalent	to	"for	all	r1,	r2,	...	such	that	ri is	subsumed	by	pi	(i	=	1,	2,	...), r1	∧	r2	∧	...	is subsumed	by	q". If so, then (20), together	with	plausible	principles about subsumption,	yields	exactly	the	biconditional	corresponding	to	our	(18). Thus	we	think	this	subsumption-theoretic	account	of	grounding	given	by	(18)	is 19	Take	any	p.	By	GI,	((p	Ù	p)	Ù	p)	o	p.	Given	that	subsumption	is	reflexive	(i.e.	that	for	p	to	hold is always a wholly relevant way for p to hold) and the further principle that subsumption, if worldly,	is	closed	under	factual	identity,	((p	Ù	p)	Ù	p)	≤	p	and	so	(p	Ù	p)	≲	p.	So	then	by	the	'irreversibility'	condition	(ii)	of	(18),	p	<	(p	Ù	p)	doesn't	hold. 27 worth	taking	seriously.	So	return	now	to	the	first	question:	what	is	subsumption? Our	proposal is that it's	simply	the	converse	of	disjunctive	parthood. If	so, then (18)	delivers	exactly	the	account	of	grounding	in	terms	of	disjunctive	parthood that	we	started	with.	Moreover,	one	can	motivate	its	extensional	adequacy	by	reflecting	on	intuitions	about	what	subsumes	what	(and	what	doesn't).	Recall	our example	of	a's	being	red	(p1)	and	a's	being	round	(p2),	which	ground	their	conjunction	(q).	Earlier,	we	simply	asserted	that it is 'eminently	reasonable' to	say that	q	is	a	conjunctive	part	of	a	disjunctive	part	of	neither	p1	nor	p2,	but	now	we can	give	it	intuitively	firmer	backing:	for	q	and	something	else	to	hold	isn't	a	wholly relevant	way	for	p1	to	hold	(since	a	part	of	q,	namely	a's	being	round,	is	intuitively irrelevant	to	a's	being	red),	and	similarly	for	p2. But	why	accept	that	subsumption	is	the	converse	of	disjunctive	parthood?	Since disjunctions	plausibly	subsume	their	disjuncts,	it	seems	safe	to	say	that	if	p	is	a disjunctive	part	of	q,	then	q	subsumes	p.	But	why	accept	the	reverse?	It	turns	out that	a	compelling	proof	for	this	biconditional	can	be	given-one	strikingly	similar to	the	proof	provided	in	section	2	that	partial	essence	is	coextensive	with	conjunctive	parthood.	It	relies	on	general	principles	about	factual	identity,	subsumption, and	their	interaction	which	are	structurally	analogous	to	those	used	in	the	earlier proof	and	just	as	plausible: (i) o	is	symmetric (ii) p	o	p	∨	p idempotence	of	∨ (iii) p	≤	q	∨	p ∨-intro	I (iv) p	≤ p	∨	q ∨-intro	II (v) If	p	≤	q,	then	p	∨	r	≤	q	∨	r ∨-adjunction	for	≤ (vi) If	p	≤	q	and	q	o	r,	then	p	≤	r substitution (vii) If	p	≤	q	and	q	≤	p,	then	p	o	q antisymmetry And	here's	the	proof: 28 Left-to-right.	Suppose	p	≤	q.	Then	by	(v),	p	∨	q	≤	q	∨	q.	By	(i),	(ii),	and (vi),	it	follows	that	p	∨	q	≤	q.	From	this,	plus	(iii)	and	(vii),	it	follows	that q	o	p	∨	q.	Hence,	there	is	some	r	such	that	q	o	p	∨	r. Right-to-left.	Suppose	that	q	o	p	∨	r for	some	r.	Then	by	(i), it	follows that	p	∨	r	o	q.	Hence	by	(iv)	and	(vi),	it	follows	that	p	≤	q. Along	with	proving	that	p	is	a	disjunctive	part	of	q	iff	q	subsumes	p	(which	is	good, albeit	defeasible,	reason	to	believe	the	one	is	the	other),	as	with	the	earlier	proof, the	left-to-right	direction	of	the	present	one	helps	dispel	worries	with	the	account of	grounding	we	gave	directly	in	terms	of	generalized	identity	earlier. Correia's	(2010)	worry	that	his	Reduction	Axiom-which	records	the	first	necessary	condition	imposed	upon	grounding	by	FACTUAL-GROUNDING-entails	that	if	a fact	p	grounds	a	fact	q,	then	q	is	the	disjunction	of	p	and	another	fact	r,	while,	on the	face	of	it,	many	grounded	facts	aren't	disjunctive	in	that	way.	Yet	the	left-toright	direction	of	the	proof	above	provides	us	with	such	a	fact:	the	improper	disjunctive	part	of	q,	namely	q	itself.	Thus,	the	worry	turns	out	to	be	unfounded. Similar	comments	apply	to	an	objection	about	how	we	handle	what	Fine	(2015) calls	generic	grounding.	We	have	in	mind	the	notion	expressed	when	one	says	that some	things	being	such-and-such	a	way	makes	them	be	such-and-such	other	way, understood	non-factively	(e.g.	when	it's	said	that	a	thing's	being	red	makes	it	be colored,	without	implying	that	anything	is	in	fact	red).	Adding	subscripts	to	Fine's "<"	notation,	we	formalize	monadic	statements	of	this	type	as	follows: F1x,	F2x,	...	<x	Gx Defining	generic	analogues	of	⊑∨	and	⊑∧∨,	generic	grounding	is	accounted	for	in	a manner	exactly	analogous	to	FACTUAL-GROUNDING: GENERIC-GROUNDING F1x,	F2x,	...	<x	Gx	iff:	(i)	F1x	Ù	F2x	Ù	... ⊑x∨	Gx;	and (ii)	neither	Gx	⊑x∧∨F1x,	nor	Gx	⊑x∧∨F2x,	... Disjunctive	properties	have	a	bad	reputation	in	metaphysical	circles.	And	though we	deny	that	GENERIC-GROUNDING	requires	the	existence	of	properties,	one	might 29 worry	that	it	renders	what's	generically	grounded	disjunctive	in	some	extended, equally	problematic	sense.	Suppose,	for	instance,	that	a	thing's	being	in	a	certain neurophysiological state	makes it be conscious.	Given GENERIC-GROUNDING, to	be conscious	is	to	be	either	in	that	neurophysiological	state	or	conscious.	So	then,	one might	worry,	as	with	the	notoriously	disjunctive	property	being	grue, things	no longer	genuinely	resemble	as	a	matter	of	their	being	conscious-from	which	one might	infer	that	being	conscious	cannot	be	causally	efficacious,	figure	into	lawful generalizations	or	inductively	confirmable	hypotheses,	and	so	on. Set	aside	whether	disjunctivity	deserves	this	bad	metaphysical	reputation,	which some	have	challenged	(cf.	Antony	2003,	Clapp	2001,	and	Skiles	2016).	Even	so, having a	disjunctive	part alone cannot suffice for	disjunctivity of this allegedly problematic	sort.	For	any	F	you	like,	a	thing's	being	either	F	or	F	is	no	different	than its	being	F	(what	else	could	it	be?);	thus	the	criterion	would	overgeneralize.	And indeed,	if	things	do	genuinely	resemble	as	a	matter	of	their	being	conscious,	then having	a	proper	disjunctive	part	cannot	suffice	for	problematic	disjunctivity	either. Even	if	being	in	the	relevant	neurophysiological	state	is	a	disjunctive	part	of	being conscious-and	even	if	being	in	the	relevant	state	is	itself	problematically	disjunctive-it	remains	the	case	that	conscious	things	in	this	state	(trivially)	genuinely resemble	conscious	things	that	aren't:	namely,	as	a	matter	of	their	all	being	conscious.	The	worry	initially	looks	compelling,	we	think,	due	to	assuming	that	being conscious	must	be	'built	up'	from	being	in	this	state	and	some	further	proper	disjunctive	part	that	bestow	no	genuine	resemblances	between	them.	But	no	such understanding	of	disjunctive	parthood	is	intended.20 Now	there	is	a	sense	in	which,	given	the	account	of	essence	developed	in	section 2,	what	is	grounded	has	a	'disjunctive	nature':	if	p1,	p2,	...	grounds	q,	then	it's	essential	to	q's	holding	that	(p1	Ù	p2	Ù	...)	Ú	q	holds.	Yet	many	find	it	objectionable for	a fact's	grounds	to figure into its	essence in	general.	As	Fine	puts it,	even if Socrates's	being	a	philosopher	grounds	that	there	are	philosophers,	the	grounded 20 What	we	say	here	is	compatible	with	the	view	that	disjunctive	parthood	obeys	weak	supplementation. The question	whether the view should be countenanced is, like the corresponding question about conjunctive	parthood (see fn. 16), substantive, and	we	hope to address it elsewhere. 30 fact's	essence	still	"knows	nothing	of	Socrates";	and	if	the	ball's	being	red	grounds its	being	colored,	the	grounded	fact's	essence	still	"knows	nothing	of	the	specific colors"	(2012,	pp.	74-75;	cf.	Rosen	2010,	pp.	130-133).	But	we	see	no	way	to	make this	worry	precise	that	we	find	troublesome.	One	can	represent	that	there	are	philosophers	in	thought	or	talk	without	reference	to	Socrates,	since	(as	we	stressed before)	generalized	identity	is	compatible	with	representational	non-equivalence. And	indeed,	we	find	it	at	least	as	intuitive	to	say	that	p1,	p2,	...	do	figure	into	the essence	of	q,	if	their	conjunction	is	subsumed	by	q	as	we've	claimed.	If	such-andsuch	are	all	wholly	relevant	ways	for	the	ball	to	be	colored,	that	hardly	seems	incidental	to	this	particular	fact. Another,	related	objection	goes	as	follows.21	Call	"C"	the	claim	that	Socrates's	being	a	philosopher	grounds	that	there	are	philosophers.	Our	account	and	C,	the	objection	starts,	together	entail	that	the	fact	f	that	there	are	philosophers	is	identical to	the	fact	g	that	Socrates	is	a	philosopher	or	there	are	philosophers.	Yet	this	is incompatible	with	the	view-call	it	"V"-that	the	existence	of	f	does	not,	while	the existence	of	g	does,	necessitate	the	existence	of	Socrates.	Therefore,	our	account, together	with	C,	precludes	V.	But	surely,	an	account	of	grounding	should	remain neutral	with	respect to	V,	even in the	presence	of	C. Hence, the	objection	concludes,	our	account	should	be	rejected.	We	deny	that	our	account	and	C	together entail	that	there	are	facts,	and	accordingly	we	would	reject	the	very	first	step	of the	objection.	But	let	us	charitably	assume	that	facts	f	and	g	do	exist.	Then	we	favor different	responses.	We	have	all	along	remained	neutral	on	the	question	whether generalized	identities	yield	objectual	identities	when	the	corresponding	entities (facts,	properties)	are	available	(see	fn.	3).	One	of	us	denies	that	they	do,	and	rejects	the	first	step	of	the	objection.	The	other	believes	that	they	do,	and	rejects	the neutrality	requirement formulated	at the	end	of the	objection.22	We	believe	the neutrality	requirement	is	not	at	all	obvious	once	we	remember	that	the	issue	here 21 Thanks	to	a	referee	for	raising	this	concern. 22 Note	that,	interestingly,	rejecting	V	doesn't	require	holding	the	view	that	everything	(f,	g	and Socrates,	in	particular)	exists	necessarily:	one	may	adopt	the	view	that	(i)	Socrates	is	a	contingent existent,	(ii)	the	fact	h	that	Socrates	is	a	philosopher	exists	at	a	world	iff	Socrates	exists	(and	perhaps:	is	a	philosopher)	at	that	world,	and	(iii)	g	has	disjunctive	existence	conditions,	existing	at	a world	iff	either	f	or	h	exists	at	that	world. 31 is the existence conditions of facts conceived of as	worldly 'chunks of reality' (whatever	those	might	be;	we're	playing	along	for	the	sake	of	argument),	not	facts conceived	of	as	propositions.	Nothing	(as far	as	we	can	see)	prevents	one from saying that the	proposition	that Socrates is a	philosopher	or there are	philosophers requires the existence of Socrates, whereas the	worldly 'chunk of reality'	this	proposition	reports	upon	doesn't.	Blurring	the	two	issues	together	might be	why	the	objection	sounds	compelling	at	first.23 Having	now	motivated	our	accounts	of	grounding	and	essence	individually,	what can	reasoning	with	their	common	ideological	core-generalized	identity-tell	us about	how	they	interact?	We	consider	this	question	in	the	remainder. 4. Fine	on	unifying	grounding	and	essence Fine	(2015)	intends,	like	us,	to	unify	essence	with	grounding.	Our	two	accounts aren't	in	direct	competition,	as	his	target	notions	aren't	the	same	as	ours:	ours	are worldly,	while	his	are	representational.24	Yet	comparing	the	two	allows	us	to	highlight	several	attractive	features	of	our	own	account	vis-à-vis	Fine's. Fine's	account	presents	a	significant	departure	from	his	older	views	on	essence and	grounding:	while	he	used	to	focus	on	the	former	in	the	objectual	sense	(as	in e.g.	his	1994)	and	on	the	latter	in	the	factual	sense	(as	in	e.g.	his	2012),	he	now acknowledges-like	Correia	(2006)-the	generic	dimension	of	essence,	and-like us-that	essence	and	grounding	can	be	either	generic	or	factual.	His	generic	notions	of	these	are	expressed,	respectively,	as: (21) It's	essential	to	x,	y,	...	being	such	that	q1,	q2,	...	that	they	be	such	that	p (in	symbols:	p	¬x,	y,	...	q1,	q2,	...) (22) Some	things	x,	y,	...	being	such	that	p1,	p2,	...	makes	them	be	such	that that	q	(in	symbols:	p1,	p2,	...	®x,	y,	...	q) His	factual	notions	can	be	expressed	as	follows: 23 See	Mulligan	and	Correia	(2013,	section	2)	for	a	survey	of	views	that	distinguish	facts	from true	propositions	and	that	allow	for	facts	to	have	disjunctive	existence	conditions. 24	Evidence	is	given	by	the	fact	that	Fine	holds	that	the	notion	of	essence	he	is	concentrating	on is	irreflexive	(2015,	pp.	296-297)	and	that	p	is	essential	to	p	Ù	p	(ibid.,	p.	308). 32 (23) It's	essential	to	its	being	the	case	that	q1,	q2,	...	that	it	be	the	case	that	p (in	symbols:	p	¬	q1,	q2,	...) (24) Its	being	the	case	that	p1,	p2,	...	makes	it	be	the	case	that	q	(in	symbols: p1,	p2,	...	®	q) The structure	of Fine's statements	of ground	mirrors that	of the statements	of ground	we're	interested	in:	one	or	more	items	ground	a	given	item.	In	contrast, Fine's	statements	of	essence	may	involve	several	items	said	to	be	(collectively)	essentially such-and-such,	whereas the statements of essence	we focused on are one-one.	Fine's	essentialist	notions	are	also	'strict',	i.e.	irreflexive	or	non-circular: an	item	cannot	be	essential	to	itself,	or	to	a	plurality	of	items	which	comprises	it. Yet	the	appearance	of	a	conflict	here	is	illusory.	For	we	can	express	the	kinds	of essentialist	statements	Fine	puts	forward,	and	account	for	them	in	a	way	perfectly dual	to	our	account	of	grounding. Use	"p	⊂x,	y,	...	q1,	q2,	..."	for	"It's	essential	to	x,	y, ...	being	such	that	q1,	q2,	...	that	p",	and	use	"p	⊂	q1,	q2,	..."	for	"It's	essential	to	its being	the	case	that	q1,	q2,	...	that	it	be	the	case	that	p",	both	understood	as	worldly and	'strict'.	Define	a	notion	of	quasi	partial	essence	⫇	as	follows: (25) p	⫇v	q	iff:	p	Ú	r	⊆v	q	for	some	r. In	other	words,	p	⫇v	q	holds	just	when	p	is	a	disjunctive	part	of	something	that	is essential	to	q.	Then	we	can	account	for	⊂-statements	as	follows: (26) p	⊂v	q1,	q2,	...	iff: (i) p	⊆v	q1	Ù	q2	Ù	...	,	and (ii)	neither	q1	⫇v	p,	nor	q2	⫇v	p,	nor	... (This	is	a	non-factive	notion;	a	factive	notion	can	be	defined	in	the	obvious	way.) Taking	⊂-statements on	board significantly improves our own	account, for	we then	see	a	perfect	parallelism	between	our	accounts	of	grounding	and	essence,	as illustrated	in	the	following	table	(corresponding	factive	notions	are	left	aside): 33 Grounding Essence Weak notion SUBSUMPTION	(≤) p	≤v	q	iff:	p	is	a	disjunctive	partv	of	q PARTIAL	ESSENCE	(⊆) p	⊆v	q	iff:	p	is	a	conjunctive	partv	of	q Quasi	weak notion QUASI	SUBSUMPTION	(≲) p	≲v	q	iff:	p	Ù	r	≤v	q	for	some	r QUASI	PARTIAL	ESSENCE	(⫇) p	⫇v	q	iff:	p	Ú	r	⊆v	q	for	some	r Strict notion STRICT	GROUNDING	(<) q1,	q2,	...	<v	p	iff: (i)	q1	Ù	q2	Ù	...	≤v	p,	and (ii)	no	qi is	such	that	p	≲v	qi STRICT	PARTIAL	ESSENCE	(⊂) p	⊂v	q1,	q2,	...	iff: (i)	p	⊆v	q1	Ù	q2	Ù	...,	and (ii)	no	qi is	such	that	qi	⫇v	p Thus our account of grounding and essence is truly	unified, for both-in their weak,	quasi	weak,	and	strict	variants-are	ultimately	accounted	for	in	terms	of	a single	notion: generalized identity. It is also	uniform, since the	account	of each ground-theoretic	variant	is	dual	to	the	account	of	the	corresponding	essentialist notion.	Substituting	conjunction	for	disjunction	in	the	account	of	p	≤v	q	yields	the account	of	p	⊆v	q;	substituting	conjunction	for	disjunction	and	disjunction	for	conjunction	in	the	account	of	p	≲v	q	yields	the	account	of	p	⫇v	q;	and	substituting	the converse	of	conjunctive	parthood	for	disjunctive	parthood	and	the	converse	of	the relation	being	a	disjunctive	part	of	a	conjunctive	part	for	the	relation	being	a	conjunctive	part	of	a	disjunctive	part	in	the	account	of	q1,	q2,	...	<v	p	yields	the	account of	p	⊂v	q1,	q2,	...	. Fine	(2015,	p.	297)	claims	that	his	own	account is	unified	and	uniform.	But	we have	our	doubts.	For	Fine,	essence	and	grounding	are	constitutive	relations:	p's being	essential	for	q1,	q2,	...	amounts	to	p's	being	what	he	calls	a	constitutively	necessary	condition	for	q1,	q2,	...,	whereas	p1,	p2,	...'s	grounding	q	amounts	to	p1,	p2,	...'s being	a	constitutively	sufficient	condition	for	q	(ibid.,	p.	306).	So	whether	a	sufficiently	deep	unity	and	uniformity	between	grounding	and	essence	is	secured	turns crucially	on	how,	exactly,	"constitutively	necessary	condition"	and	"constitutively sufficient	condition"	are	to	be	understood. We	can	see	two	options,	but	neither	seems	up	to	the	task.	One	is	that	"p	is	a	constitutively	necessary	condition	for	q"	is	to	be	understood	as	"p	is	constitutive	of	q, and	a	necessary	condition	for	q",	and	"p	is	a	constitutively	sufficient	condition	for 34 q"	as	"p	is	constitutive	of	q,	and	a	sufficient	condition	for	q".	The	problem,	at	least if	"necessary	condition"	and	"sufficient	condition"	are	understood	in	the	familiar modal	fashion,	is	that	unacceptable	results	follow.	For	instance,	being	a	number (F)	is	essential	to	being	a	number	and	blue-or-not-blue	(G).	So,	being	F	is	constitutive	of	being	G.	But	since	being	F	necessarily	implies	being	G,	the	view,	understood modally,	entails	that	being	F	grounds	being	G	(and	it	doesn't). Now, Fine acknowledges notions of necessary and sufficient conditions which aren't	modal,	and	which	are	not	converse	to	each	other	(ibid.,	pp.	306-7),	and	it may	be	thought	that	the	view	in	question	is	instead	to	be	read	as	invoking	these. But	now	we	are	left	with	one	problem,	which	also	affects	the	modal	view:	how	is this	notion	of	being	constitutive	of	to	be	understood?	Absent	a	fuller	story,	the	account	seems	incomplete. The	second	option	is	to	claim	that	"constitutively"	in	the	phrases	"constitutively necessary/sufficient	condition"	is	intended	to	mark	two	kinds	of	non-modal	condition-the constitutively-necessary kind vs. the constitutively-sufficient kind- which	differ	in	their	modal	import.	But	this	option	seems	at	least	as	problematic as	the	previous	one.	The	previous	option	secured	at	least	some	form	of	unity	in the	account	of	essence	and	grounding,	as	both	are	analyzed	in	terms	of	a	single notion:	being	constitutive	of.	Yet	with	the	present	option,	it	is	not	at	all	clear	what unifies	constitutively-necessary	conditions	with	constitutively-sufficient	ones	in more	than	name	only,	or	why	these	non-modal	conditions	have	the	modal	import they	allegedly	do.	Perhaps	part	of	the	explanation	is	that	both	are	determinates	of the	same	determinable:	being	a	constitutive	condition	of.	But	again:	how	is	this	notion	to	be	understood?	Absent	a	fuller	story,	the	account	seems	incomplete.	Our account,	in	contrast,	analyzes	grounding	and	essence	in	terms	of	the	same	family of	notions,	which	we	backed	up	with	a	theory	about	these	notions	we	take	to	be independently	motivated	by	how	we	intuitively	understand	"For	...	is	for	___"	statements	as	they're	used	in	philosophical	settings. Fine	(ibid,	p.	308)	also	claims	that	both	constitutive	relations	are	to	be	taken	as primitive.	Now	of	course,	we	have	no	basis	for	faulting	Fine	for	this	reason	alone: we've	assumed	(for	the	purposes	of	this	paper,	at	least)	that	generic	and	factual 35 identity	are	not	reductively	analyzable	either.	Even	so,	working	with	this latter class of primitives has significant advantages over	working	with Fine's.	We've mentioned	a	number	of	respects	in	which	our	account	is	appealing	when	applied to	essence	and	grounding	individually.	Given	that	these	depend	crucially	on	the distinctive	features	of	generalized	identity,	it	at	best	is	unclear	how	to	replicate them	within	Fine's	account-that	is,	absent	an	as-yet	untold	story	about	the	nature	and	logic	of	constitutive	relations.	(Not	that	the	nature	and	logic	of	generalized	identity	is	completely	transparent;	but	at	least	there	are	tight	analogies	with another,	more	familiar	'no-difference'	notion	to	guide	us,	i.e.	objectual	identity.) This	becomes	even	more	apparent	when	we	use	generalized	identity	to	evaluate principles	linking	grounding	and	essence.	For	instance,	Fine	claims	that	if	being	F grounds	being	G,	then	being	G	"will	not	in	general	(and	perhaps	will	never	be)" part	of	what	it	is	to	be	F;	for	otherwise,	being	F	would	be	constitutive	of	being	G and	vice	versa	(ibid.,	pp.	306-7).	But	this	explanation	strikes	us	as	incomplete.	If being constitutively-necessary for and	being constitutively-sufficient for	are	both primitive,	why couldn't the two	hold in opposite	directions? In contrast, Fine's claim	follows	immediately	from	our	framework.	For	suppose	Fx	<x	Gx.	Then	by	our account	of	grounding,	it's	not	the	case	that	Gx	≲x	Fx.	Suppose	for	reductio	that	Gx ⊂x	Fx.	Then	by	our	account	of	strict	essence,	Gx	⊆x	Fx.	By	our	account	of	partial essence,	this	means	that	Fx	ox	Gx	Ù	Hx	for	some	H.	By	axiom	A3	of	GI	and	the	transitivity	of	o,	it	follows	that	Fx	ox	(Gx	Ù	Hx)	Ú	(Gx	Ù	Hx).	By	our	account	of	subsumption,	it	follows	that	Gx	Ù	Hx	≤x	Fx,	which,	by	our	definition	of	≲,	implies	that	Gx	≲x Fx.	Contradiction. The	framework	also	affords	us	resources	to	respond	to	a	worry	with	Fine's	claim. It's	plausible	to	think	that	being	red	grounds	being	colored,	and	that	it	is	part	of what	it	is	to	be	red	is	to	be	colored.	Although	we	accept	the	grounding	claim,	we reject the essentialist claim. But	why does the essentialist claim seem correct? Here	are	two	(compatible)	hypotheses.	First,	if	being	red	grounds	being	colored,	a thing's	being	colored	is	in	full	its	either	being	red	or	(otherwise)	colored,	and	so is-unlike,	say,	its	being	either	human	or	not	human-relevantly	necessitated	by its	being	red.	The	idea	that	being	colored	is	part	of	what	it	is	to	be	red	might	simply 36 be	prompted	by	this	separate	fact. Second,	perhaps	a	generic	essentialist	falsehood	about	being	red	is	being	confused for	an	objectual	essentialist	truth	about	the	property	being	red:	i.e.,	that	being	a color	is	part	of	what	it	is	to	be	this	very	property.	Suppose	this	is	so,	and	that	a thing	cannot	be	red	without	having	this	property.	Then	it	follows	that	the	thing has	a	property	which	is	a	color	(or,	to	put	it	more	naturally,	that	it	has	a	color). Presumably,	a	thing's	having	a	color	just	is	its	being	colored;	thus	it	follows	that	a thing	cannot	be	red	unless	it's	also	colored.	Given	how	subtle	these	distinctions between	the	objectual	and	generic	can	be,	perhaps	it	shouldn't	surprise	us	that one	essentialist	claim	is	confused	for	the	other. Here	are	two	further	examples	of	how	generalized	identity	illuminates	the	unity of	grounding	and	essence.	First,	consider	the	claim	that	grounding	holds	only	if there	is	some	'underlying'	truth	about	essence.25	Our	account	predicts	at	least	one sense in	which this is correct. Specifically, our account predicts that if being	F grounds	being	G, the	fact	that	being	F	necessitates	being	G	can	be	derived	from what	it	is	to	be	G.	For	if	being	F	grounds	being	G,	our	account	implies	that	being	G just	is	being	F	or	H	for	some	given	H,	and	which	on	our	account	gives	the	(or	a)	full essence	of	being	G.	It	then	follows	that	necessarily,	a	thing	is	G	iff	it	is	F	or	H,	which entails	by	straightforward	modal	reasoning	that	necessarily,	a	thing	is	F	only	if	it's also	G,	as	desired.26 Second,	consider	the	claim	that	not	every	necessary	entailment	or	equivalent	of such-and-such	is	also	essential	to	it.	This	is	only	true	in	some	cases-but	in	which cases	is	it	false?	Our	account	allows	appeal	to	ground-theoretic	resources	when addressing the	question.	Specifically, since (worldly) ground-theoretic status is preserved	under	generalized	identity,	our	account	entails	that	being	F	is	at	least in	part	of	what	it	is	to	be	G,	only	if	F	is	ground-theoretically	equivalent	to	being 25	For	discussion	of	principles	of	this	type,	see	the	articles	cited	in	fn.	1. 26	Some	argue	that	what's	grounded	needn't	be	necessitated	by	what	grounds	it,	but	see	Skiles (2013,	ch.	4;	2015,	pp.	739-41)	for	an	alternative	identity-based	proposal	of	grounding	designed to	be	compatible	with	'grounding	contingentism'.	Whether	Skiles's	proposal	and	the	one	defended in	this	paper	should	be	viewed	as	competitors-or	instead	as	characterizing	two	kinds	of	grounding	under	one	ideological	umbrella-is	an	interesting	question,	but	for	another	time. 37 both	F	and	G	(in	the	sense	discussed	in	section	2).	Yet	this	needn't	always	be	the case	if	being	F	is	necessarily	entailed	by	or	equivalent	to	being	G.	To	recall	one	of Fine's	(1994)	famous	examples:	being	Socrates	and	such	that	there	are	infinitely many	prime	numbers	is	necessarily	entailed	by	and	equivalent	to	being	Socrates, yet	presumably	the	former	is	ground-theoretically	linked	to	the	arithmetic	realm in	ways	that	the	latter	isn't.	Given	our	account,	this	provides	reason	to	believe	that the	former	isn't	part	of	the	essence	of	the	latter	either,	as	desired. To	be	clear,	we	don't	claim	that	Fine's	account	cannot	be	supplemented	with	an informative	story	of	what	constitutive	relations	are	that	performs	as	well in its intended	domain.	We	do,	however,	think	that	these	comparisons	bring	some	of	the attractive	features	of	our	account	into	stark	relief. 6. Looking	forward We	have	argued	that	grounding	and	essence	can	both	be	accounted	for	in	terms	of identity-generalized	identity-and	explained	why	the	resulting	framework	is	attractive.	But	this	is	hardly	the	last	word	on	the	matter.	At	least	two	classes	of	questions	emerge	for	further	work. One	class	concerns	how	generalized	identity-and	thus,	on	our	view,	grounding and	essence-fit	into	our	cognitive	lives.	Such	questions	include:	can	the	account be	extended	to	representational	notions	of	grounding	and	essence?	How	does	one come to know which statements of generalized identity hold? And why does grasping	some	of	them	bring	at	least	some	degree	of	explanatory	understanding, while	grasping	others	(e.g.	"To	be	human	is	to	be	human")	doesn't? Another	class	of	questions	instead	concerns	how	generalized	identity-and	thus, on	our	view,	grounding	and	essence-fit	into	fundamental	reality.	These	include: are	generic	and	factual	identity	primitive	notions,	as	we've	assumed?	What	(if	anything)	grounds	facts	about	what	is	generically/factually	identical	to	what?	And do	these	notions	fall	under	the	same	ideological	kind	as	objectual	identity? We suspect that existing	work on questions such as these, inside	metaphysics proper	and	out,	would	prove	highly	useful	for	answering	related	questions	about grounding	and	essence.	Grounding,	essence,	and	identity individually	have	been 38 topics	at	the	center	of	metaphysical	inquiry	for	quite	some	time.	A	fuller	understanding	of	how	the	three	behave	collectively	should,	we	think,	be	at	the	center	of metaphysical	inquiry	for	some	time	to	come.27 References Anderson,	Alan	&	Nuel	Belnap	(1962),	"Tautological	Entailments",	Philosophical	Studies, 13,	pp.	9-24. ________	(1963),	"First	Degree	Entailments",	Mathematische	Annalen,	149,	pp.	302-319. Angell,	Richard	(1977), "Three	Systems	of	First	Degree	Entailment, Journal	of	Symbolic Logic,	42,	p.	147. ________	(1989),	"Deducibility,	Entailment,	and	Analytic	Containment",	in	Jean	Norman	& Richard	Sylvan	(eds.),	Directions	in	Relevant	Logic,	Dordrecht:	Kluwer,	pp.	119-143. Antony,	Louise	(2003),	"Who's	Afraid	of	Disjunctive	Properties?",	Philosophical	Issues,	13, pp.	1-21. Audi,	Paul	(2012),	"Grounding:	Toward	a	Theory	of	the	In-Virtue-Of	Relation",	Journal	of Philosophy,	109,	pp.	685-711. ________	(2015),	"Explanation	and	Explication",	in	Chris	Daly	(ed.),	The	Palgrave	Handbook of	Philosophical	Methods,	Basingstoke:	Palgrave	Macmillan,	pp.	208-230. Bliss,	Ricki	&	Kelly	Trogdon	(2014),	"Metaphysical	Grounding",	in	Edward	Zalta	(ed.), The	Stanford	Encyclopedia	of	Philosophy	(spring	2016	edition),	URL	= <http://plato.stanford.edu/archives/spr2016/entries/grounding/> Cameron,	Ross (2014), "On the	Lack	of	Direction in	Rayo's	The	Construction	of	Logical Space",	Inquiry,	57,	pp.	427-441. 27	For	their	comments	on	ancestors	of	this	article,	we	wish	to	thank	Dominik	Aeschbacher,	Andrew	Bailey,	Riccardo	Baratella,	Sam	Baron,	Corrine	Besson,	Philipp	Blum,	Martina	Botti,	Claudio Calosi,	Pablo	Carnino,	Rebecca	Chan,	Michael	J.	Clark,	Christina	Conroy,	Paul	Daniels,	Louis	deRosset, Cian Dorr, Jeremy Goodman, Dana Goswick, Vincent Grandjean, Ghislain Guigon, Miguel Hoeltje,	Kathrin	Koslicki,	Olivier	Massin,	Anna-Sofia	Maurin,	Kris	McDaniel,	Neil	Mehta,	Robert	Michels,	Kevin	Mulligan,	Benjamin	Neeser,	Donnchadh	O'Conaill,	Bryan	Pickel,	Jan	Plate,	Mike	Raven, Agustín	Rayo,	Henrik	Rydéhn,	Pierre	Saint-Germier,	Maria	Scarpati, Jonathan	Schaffer, Jonathan Simon, Robin Stenwall, Tuomas Tahko, Elanor Taylor, Naomi Thompson, Kelly Trogdon, Jan Walker,	Jennifer	Wang,	Nathan	Wildman,	Tobias	Wilsch,	Justin	Zylstra,	several	anonymous	referees,	and	audiences	in	Ascona,	Bergamo,	Bern,	Bucharest,	Dresden,	Geneva,	Gothenburg,	Helsinki, Istanbul	(Koç),	Leeds,	London	(King's	College),	Neuchâtel,	Oslo,	Oxford,	and	Sassari.	This	article was written while F.C. was funded through the Swiss National Science Foundation projects "Grounding	–	Metaphysics,	Science,	and	Logic"	(CRSII1-147685),	"The	Metaphysics	of	Time	and	its Occupants" (BSCGI0_157792),	and	"Essences, Identities	and Individuals" (100012_159472), the University	of	Neuchâtel's	module	of	the	European	Commission's	HORIZON	2020	Marie	Sklodowska-Curie	European	Training	Network	DIAPHORA	(H2020-MSCA-ITN-2015-675415),	while	A.J.S. received	funding	as	a	Swiss	NSF	Advanced	Postdoc.Mobility	researcher	in	the	project	"Metaphysics as	an	Explanatory	Discipline:	Grounding,	Essence,	and	Identity"	(167721),	and	while	both	received funding	through	the	Swiss	NSF	project	"The	Nature	of	Existence:	Neglected	Questions	at	the	Foundations	of	Ontology"	(10012_150289).	We	are	grateful	for	their	generous	support. 39 Carnino,	Pablo	(2015),	"On	the	Reduction	of	Grounding	to	Essence",	Studia	Philosophica Estonica,	7,	pp.	56-71. 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