Epistemic	Modality,	Eavesdroppers	and	the	Objectivity	Problem Wylie	Breckenridge There is an account of	modal operators that is both elegant and powerful and that deserves	to	be	called	the	standard	account.	There	are,	however,	some	epistemic	uses of	modal operators	which seem to be counterexamples to the account – they pose what	I	call	the	objectivity	problem.	It	is	often	thought	that	the	objectivity	problem	can be	fixed	by	a	certain	kind	of	modification	to	the	standard	account.	I	argue	that	this	kind of	modification cannot	work. Then I argue that the problem	posed for the standard account	by	recently	discussed	eavesdropper	cases	is	really	just	the	objectivity	problem in	a	different	guise,	thereby	emphasizing	the	need	for	a	new	solution	to	the	objectivity problem.	Finally,	I	propose	a	new	solution	to	the	objectivity	problem. 1.	The	standard	account According to what I shall call the standard account of possibility operators, an utterance	of 'Possibly	S'	(and	its	variants 'It is	possible	that	S', 'It	might	be	that	S', 'It can	be	that	S',	etc.) in	a	context	C	is	true	if	and	only	if	the	prejacent	(the	proposition expressed by S in C) is compatible with the conversational background (a set of propositions	determined	by	C).1	If	we	analyze	compatibility	in	terms	of	worlds	then	we can	put	it	this	way:	the	utterance	is	true	iff	there	is	a	world	in	which	the	prejacent	and the propositions in the conversational background are all true. Different kinds of possibility correspond to different kinds of conversational background: if the conversational	background	is	a	body	of	knowledge	then	the	utterance	is	an	epistemic use	of	'Possibly	S';	if	it	is	a	set	of	laws	or	regulations	then	it	is	a	deontic	use;	if	it	is	a	set of	desires	then	it	is	a	bouletic	use;	and	so	on.	As	stated,	the	account	allows	that	when 'Possibly S' is used epistemically there is flexibility in whose knowledge forms the conversational	background	–	it	could	be	the	knowledge	of	the	speaker,	the	knowledge of	someone	other	than	the	speaker,	or	the	knowledge	of	some	group	of	people	which may	or	may	not	include	the	speaker. 2.	The	objectivity	problem There	is	a	problem	for	the	standard	account	that	has	been	recognized	for	some	time. Here	is	an	old	and	well-known	example	due	to	Hacking	(1967,	p.	148): Salvage	ship Imagine	a	salvage	crew	searching	for	a	ship	that	sank	a	long	time	ago.	The	mate of the salvage ship works from an old log, makes some mistakes in his calculations,	and	concludes	that	the	wreck	may	be	in	a	certain	bay.	It	is	possible, he	says,	that	the	hulk	is	in	these	waters.	No	one	knows	anything	to	the	contrary. But	in	fact,	as	it	turns	out	later,	it	simply	was	not	possible	for	the	vessel	to	be	in that	bay;	more	careful	examination	of the log shows that the	boat	must	have gone down at least thirty	miles further south. The	mate said something false 1 See	Kratzer	(1977,	1981,	1991),	and	von	Fintel	(2006). 2 when he said, 'It is possible that we shall find the treasure here,' but the falsehood	did	not	arise	from	what	anyone	actually	knew	at	the	time. The	problem	is	that	the	mate's	utterance	of	'It	is	possible	that	the	wreck	is	in	that	bay' is	false,	even	though	the	prejacent	(the	proposition	expressed	by	'the	wreck	is	in	that bay')	is	compatible	with	what	anyone	knows	at	the	time.	So	no	matter	which	body	of knowledge	we	take,	the	prejacent	is	compatible	with	that	body	of	knowledge,	and	the standard	account	wrongly	predicts	that	the	mate's	utterance	is	true.	The	case	suggests that the truth	of	an	epistemic	utterance	of 'Possibly	S'	can	depend	upon facts	about the	world that	are	not	known to	anyone	at the time, contrary to	what the standard account	predicts.	Call	this	the	objectivity	problem. Not everyone agrees that the mate's utterance is false. They ask: "Why is it not epistemically possible that the	wreck is in that bay, given that it is compatible	with what anyone knows at the time that it is? Perhaps it is not possible in some other sense,	but	in	an	epistemic	sense	it	is."	If	they	are	right	that	the	mate's	utterance	is	not false	then	there	is	no	problem	here	for	the	standard	account.	But	many	people	agree that the	mate's	utterance is false,	and	that there is	a	problem	here for the	standard account.	My	question	is:	if	so,	then	what	should	the	standard	account	do	about	it? 3.	A	popular	fix One popular way of dealing with the objectivity problem is to allow that the conversational background	determined	by an	epistemic	utterance	of 'Possibly S' can include	not	just	what	is	known	(by	some	person	or	group	of	persons)	but	also	what	can be known (what is within 'epistemic reach', as Egan (2007) would say). The	mate's utterance	is	false,	not	because	the	prejacent	is	incompatible	with	what	is	known	at	the time,	but	because	it	is	incompatible	with	what	can	be	known	at	the	time	(that	the	log rules	out	the	wreck	being	in	that	bay).	Call	this	the	popular	fix. It is well known that the popular fix needs to place restrictions on what counts as knowable relative to an utterance	of 'Possibly S', or else there are	many	utterances that	it	wrongly	predicts	to	be	false.	Take	any	location	L	for	which	an	utterance	by	the mate	of 'It is	possible that the	wreck is	at L' is true,	but the	wreck is	not	at L. If	we allow	that	it	can	be	known	that	the	wreck	is	not	at	L	(for	example,	by	diving	at	L	and looking),	then	it	is	not	compatible	with	what	can	be	known	that	the	wreck	is	at	L,	and so	the	utterance	is	wrongly	predicted	to	be	false.	So	to	get	the	right	result	the	popular fix	has	to	say	that	relative	to	this	utterance	it	cannot	be	known	that	the	wreck	is	at	L. Hacking (1967) proposes that only things that can be known by some practical investigation count as things that can be known (diving at L and looking is not practical); De Rose (1991) proposes that only things that can be known by some method	in	a	contextually	determined	set	of	relevant	methods	count	as	things	that	can be	known	(diving	at	L	and	looking	is	not	a	relevant	method). There	are	known	problems	for	each	of	these	two	ways	of	putting	restrictions	in	place (see	Egan	(2007),	von	Fintel	and	Gillies	(2008)).	But	I	have	more	serious	concerns	about the	general	approach	of	the	popular	fix. 3 4.	Concerns	about	the	popular	fix I	have	one	objection	and	two	challenges. First,	an	objection.	There	are	cases	in	which	the	unknown	fact	that	makes	an	utterance of	'Possibly	S'	false	is	an	unknowable	fact,	so	appealing	to	what	can	be	known	to	solve the	objectivity	problem	is	bound	to	fail.2	Here	are	three	examples,	each	of	which	aims to	be	structurally	analogous	to	the	salvage	ship	case,	but	in	which	the	falsifying	fact	is unknowable: First	example.	Suppose	that	John	believes	that	Descartes	had	between	200	and 400 books on his bookshelf and is not open to it being otherwise. He is wondering	whether	it	was	between	200	and	300	or	between	300	and	400,	and asserts	'It	might	have	been	between	200	and	300'.	If	in	fact	Descartes	had	only ten books on his bookshelf then John's utterance is false. But the fact that Descartes had only ten books on his bookshelf is not something that John or anyone	else	can	know. Second	example.	Suppose	that	epistemicism	about	vagueness	is	right,	and	there can	be	people	who	are	not	thin	but	unknowably	not	thin.	Suppose	that	Mary	is unknowably	not	thin.	John	believes	that	Mary	is	thin	and	is	not	open	to	it	being otherwise.	He	is	wondering	whether,	of	all	the	thin	girls,	Mary	is	the	prettiest. He thinks that she stands a good chance and asserts 'Mary might be the prettiest thin	girl'.	But	Mary is	not	even thin, so John's	utterance is false,	and the fact that	Mary is not thin is not something that John or anyone else can know. Third example. Suppose that John thinks that it is not an	unknown truth that there is life	on Jupiter	and is	not	open to it	being	otherwise.	He is	wondering whether it is (a) false,	or (b) true	but	not	known.	He	asserts 'It	might	be false that	there	is	life	on	Jupiter'.	If	in	fact	it	is	an	unknown	truth	that	there	is	life	on Jupiter then John's	utterance is false.	But the fact that it is	an	unknown	truth that	there	is	life	on	Jupiter	is	not	something	than	John	or	anyone	else	can	know. Each	of	these	cases	has	the	same	structure	as	the	salvage	ship	case:	Someone	asserts 'Possibly	S';	there	is	some	true	proposition	q	which	is	incompatible	with	the	prejacent p,	and	because	of	which	the	utterance	is	false;	but	q	is	not	something	that	anyone	at the time knows. According to the standard fix, the utterance is false because q is something that can be known (within certain restrictions). But the three examples above	show	that there	are	cases in	which	q	cannot	be	known,	so	that	no	amount	of tinkering	with	restrictions	will	get	the	standard	fix	to	work. That	is	my	objection	to	the	standard	account.	In	addition,	I	have	two	challenges. 2 Thanks	to	Stephen	Kearns. 4 First,	we	have	what	I	call	the	openness	observation.	When	the	truth	of	an	utterance	of 'Possibly	S'	depends	upon	facts	about	the	world	that	are	not	known	to	anyone	at	the time,	it	can	do	so	in	a	way	that	depends	upon	what	the	speaker	is	open	to	during	the utterance.	This is	a feature	of	all the	above	cases that I	haven't	yet	emphasized,	but one	that	is	important.	On	the	most	natural	way	of	understanding	the	salvage	ship	case, the	mate	is	not	open	to	the	log's	ruling	out	that	the	wreck	is	in	that	bay.	But	if	we	add to the story that he is (that he has some	doubts about his calculations), then	many now	judge	that	the	mate's	utterance is true,	and	that	upon	re-examining	the log	the mate	would be right to stand	by his original claim and say, 'It still	might have been there'.	Similarly,	in	the	examples	above,	if	John	were	open	to	Descartes	having	had	ten books	on	his	bookshelf	then	his	utterance	would	not	be	false,	if	he	were	open	to	Mary not	being	tall	then	his	utterance	would	not	be	false,	and	if	he	were	open	to	it	being	an unknown	truth	that	there	is	life	on	Jupiter	then	his	utterance	would	not	be	false. It seems	difficult for the	popular fix to	account for the	openness	observation. In the salvage	ship	case,	let	p	be	the	proposition	that	the	log	rules	out	the	wreck	being	in	that bay.	If	the	popular	fix	is	right	then	we	have	the	following	correlation:	if	the	mate	is	not open	to	p	then	p	can	be	known	(so	that	his	utterance	of	'It	is	possible	that	the	wreck	is in that bay' is false); if the	mate is open to p then p cannot be known (so that his utterance of 'It is possible that the wreck is in that bay' is true). Prima facie these correlations	are	the	wrong	way	around,	and	there	is	a	challenge	here	for	the	popular fix	to	explain	them. My second	challenge is this. The standard	account faces the	objectivity	problem	not just	with	epistemic	uses	of 'Possibly	S'	but	with	non-epistemic	uses	as	well.	Here	are two	examples: Metaphysical	use John rolls a die and it comes up '3'. He asserts, 'I might have rolled a '2'' (intending a metaphysical reading). There are worlds in which the prejacent (that John rolled	a '2') and the	propositions in the conversational	background (the metaphysical laws) are all true, so on the standard account John's utterance	is	true.	But	if	the	die	that	John	is	using	has	a	'3'	on	all	sides	then	his utterance is false (assuming that John is not open to swapping his die for a regular	one	before	rolling	it	–	if	he	is	then	his	utterance	is	true). Deontic	use John is looking for a parking space in downtown Ithaca. The Ithaca council provides	special	parking	spaces	for fuel	efficient	cars.	Pointing	to	one	of	these spaces	John	asserts, 'I	can	park	there' (intending	a	deontic	reading).	There	are worlds in	which the	prejacent (that John	parks there) and the	propositions in the	conversational	background	(the	parking	regulations)	are	all	true,	so	on	the standard	account	John's	utterance	is	true.	But	if	John	is	driving	a	Hummer	then John's	utterance	is	false	(assuming	that	John	is	not	open	to	swapping	his	car	for a	fuel	efficient	one	before	parking	–	if	he	is	then	his	utterance	is	true). 5 It is	not	clear	how	the	popular	fix	might	be	extended	to	these	cases.	The	natural	first try	is	as	follows:	in	the	metaphysical	case,	the	conversational	background	can	include not just things that are	metaphysical laws but also things that can be	metaphysical laws,	and	it	can	be	a	metaphysical	law	that	John	uses	a	die	with	a	'3'	on	all	sides;	in	the deontic case, the conversational background can include not just things that are parking regulations but also things that can be parking regulations, and it can be a parking regulation that John drives a Hummer. This does not seem like a promising approach, so there is a challenge here for the present approach to come	up	with a more	promising	way	of	extending	to	other	kinds	of	possibility. Note	that	in	the	metaphysical	and	deontic	cases	just	given	we	also	have	the	openness observation	– that the truth	of an	utterance	of 'Possibly S' can	depend	on	what the speaker	is	open	to	at	the	time	of	the	utterance.	What	we	would	like	is	a	solution	to	the objectivity	problem	and	an	explanation	of	the	openness	observation	that	extends	to	all kinds	of	possibility. I think	that	with	a	simple	and	well-motivated	modification	of the standard	account	we	can	get	just	that	(see	Section	6). But	before	that,	some	remarks	about	eavesdropper	cases. 5.	Eavesdropper	cases There	has	recently	been	some	discussion	of	epistemic	uses	of	'Possibly	S'	in	cases	that involve	eavesdroppers.	Here	is	simple	case	as	it	might	typically	be	described: Two	cups John is trying to	work	out	which	of two	cups	a	ball is	under.	He	asserts (with warrant),	'The	ball	might	be	under	cup	1'.	In	fact	the	ball is	under	neither	cup. An	eavesdropper	who	knows	that	the	ball	is	under	neither	cup	judges	'false'	of John's	utterance.	Her	judgment	is	correct. Not	everyone	agrees	that	the	eavesdropper	is	correct	to	judge	'false',	but	assume	for the	moment that she is (I	will offer an explanation	of this below). The case	poses a problem for the standard account. According to the standard account, John's utterance	is	false	just	in	case	it	is	not	compatible	with	the	conversational	background (a	body	of	knowledge)	that	the	ball	is	under	cup	1.	So	if	the	eavesdropper	is	correct	to judge 'false', then the conversational background cannot be merely John's body of knowledge,	because	it	is	compatible	with	what	John	knows	that	the	ball	is	under	cup	1. If	the	conversational	background	includes	the	eavesdropper's	body	of	knowledge	then we	get the	result that the	eavesdropper is	correct to judge 'false',	but then	we	have trouble	explaining	why	John	is	warranted	in	making	the	assertion	in	the	first	place	–	he has	no	idea	(we	can	add)	whether	or	not	he	has	an	eavesdropper,	or	how	much	such an eavesdropper might know, so if the truth of his utterance is sensitive to the knowledge	of	any	eavesdropper,	then	he	is	not	warranted	in	making	the	assertion.	Call this	the	eavesdropper	problem. In	response	to	the	eavesdropper	problem,	Egan	et.	al.	(2005),	Egan	(2007),	MacFarlane (2008),	and	others	have	defended	a	relativist	account	of	epistemic	uses	of	'Possibly	S'. 6 According	to	this	account,	the	truth	of	an	epistemic	utterance	of	'Possibly	S'	is	not	true or false simpliciter but only relative to an assessor and a time. In particular, an epistemic	utterance	of 'Possibly S' in a context	C is true relative to an	assessor	A at time	t	iff	the	prejacent	is	compatible	with	everything	that	A	knows	at	t.	In	the	two	cups case,	John's	utterance	is	true	relative	to	John	at	the	time	of	the	utterance	(since it is compatible	with	everything	that	John	knows	at	the	time	of	the	utterance	that	the	ball is	under	cup	1)	and	that is	why	John is justified in	making	the	assertion (perhaps	we need	to	add	that	John	knows	that	his	utterance	is	true	relative	to	him	at	the	time).	But relative to the eavesdropper at the time of her judgment John's utterance is false (since	it	is	not	compatible	with	everything	that	the	eavesdropper	knows	at	the	time	of the	judgment	that	the	ball	is	under	cup	1),	and	that	is	why	the	eavesdropper	is	correct to judge 'false' (i.e. false relative to her at the time of the judgment). The relativist account	thus	allows	that	John	is justified in	asserting	'The	ball	might	be	under	cup	1' and	that	the	eavesdropper	is	correct	to	judge	'false'. Rejecting the relativist account, von Fintel and	Gillies's (2008) propose that coupled with a sufficiently enriched pragmatic theory the standard account can handle eavesdropper	cases.3	According	to	the	standard	account,	an	epistemic	use	of	'Possibly S' determines a certain body	of knowledge as the conversational background, but it does	not	make	explicit	exactly	which	body	of	knowledge	this	is,	and	this	can	give	rise	to an	interpretational	ambiguity.	von	Fintel	and	Gillies	propose	that	sometimes	speakers exploit this	ambiguity,	and	would	say that this is	what John is	doing in the two	cups case. By uttering 'The ball might be under cup 1', John puts into play at least two propositions, one being a solipsistic reading of 'The ball might be under cup 1' (on which	the	conversational	background	is	everything	that	John	knows),	the	other	being	a group reading (on	which the conversational background is everything that John and the	eavesdropper	together	know).	John	is	warranted	in	making	the	utterance	because he	is	warranted	in	asserting	at	least	one	of	these	two	propositions	(the	solipsistic	one). The eavesdropper is pragmatically obliged to react to the strongest proposition she reasonably	has	an	opinion	about,	which	is	the	group	reading.	Since	the	group	reading is	false,	the	eavesdropper	is	correct	to	judge	'false'.	This	ambiguity	by	design	account thus	allows	that	John	is	justified	in	asserting	'The	ball	might	be	under	cup	1'	and	that the	eavesdropper	is	correct	to	judge	'false'. The	relativist	and	ambiguity	by	design	accounts	both	assume	a	certain	explanation	for why	the	eavesdropper	is	correct	to	judge	'false':	she	is	correct	to	judge	'false',	because when she assesses John's utterance her body of knowledge is to be included in the conversational background of the utterance, and her body of knowledge is incompatible with the prejacent of the utterance (had it been compatible with the prejacent	then	her	judgment	would	not	have	been	correct). But	is	this	the	right	explanation?	Here	is	an	alternative:	the	eavesdropper	is	correct	to judge 'false' because John's utterance is false, and John's utterance is false because the ball is under neither cup, something that John	was not open at the time	of the utterance.	In	short,	this	is	just	another	instance	of	the	objectivity	problem.	Whether	or not	the	eavesdropper	is	correct	to	judge	'false'	does	not	depend	on	what	she	knows. 3 Against	the	relativist	account	also	see	Hawthorne	(2007)	and	Wright	(2007). 7 Whether	or	not she is	warranted to judge 'false'	might	depend	on	what she knows, and	perhaps	she	judges	'false'	because	of	what	she	knows,	but	whether	or	not	she	is correct	to	judge	'false'	does	not	depend	on	what	she	knows. Which	is	the	better	of	these	two	explanations?	Here	are	some	reasons	to	think	that	it is	the	latter. First,	consider	a	modified	case	in	which	the	eavesdropper	is	ignorant	of	where	the	ball is,	and	judges	'false'	just	as	a	guess.	In	this	case	her	judgment	is	still	correct: Two	cups	(ignorant	eavesdropper) John	is	trying	to	work	out	which	of	two	cups	the	ball	is	under.	He	asserts,	'The ball might be under cup 1'. In fact the ball is under neither. An ignorant eavesdropper	guesses	'false'	of	John's	utterance.	Her	guess	is	correct. According to the first explanation the eavesdropper's judgment is not correct – her body	of	knowledge	is	compatible	with	the	ball	being	under	cup	1,	so	she	is	not	correct to	judge	'false'.	According	to	the	second	explanation	her	judgment	is	correct	–	it	is	still the	case	that	the	ball	in	under	neither	cup,	something	that	John	is	not	open	to.	So	the second	explanation	fares	better. Second, consider a modified case in which the ball is under cup 2, and the eavesdropper knows that the ball is under cup 2. In this case her judgment is not correct: Two	cups	(cup	2) John	is	trying	to	work	out	which	of	two	cups	the	ball	is	under.	He	asserts,	'The ball	might	be	under	cup	1'.	In	fact	the	ball	is	under	cup	2.	An	eavesdropper	who knows that the ball is under cup 2 judges 'false' of John's utterance. Her judgment	is	not	correct. According	to	the	first	explanation	the	eavesdropper's	judgment	is	correct	–	her	body	of knowledge	is incompatible	with	the	ball	being	under	cup	1,	so	she	is	correct	to	judge 'false'.	According to the	second	explanation	her judgment is	not	correct	– the	ball is under	cup	2,	something	that	John	is	open	to.	So	the	second	explanation	fares	better. Third,	consider	a	modified	case	in	which	John	is	open	to	the	ball	being	under	neither cup.	In	this	case,	again,	the	eavesdropper's	judgment	of	'false'	is	not	correct: Two	cups	(open-minded) John	is	trying	to	work	out	which,	if	any,	of	two	cups	the	ball	is	under	(he	is	open to it	being	under	neither cup).	He	asserts, 'The	ball	might	be	under cup	1'. In fact	the	ball	is	under	neither.	An	eavesdropper	who	knows	that	the	ball	is	under neither	judges	'false'	of	John's	utterance.	Her	judgment	is	not	correct. According	to	the	first	explanation	the	eavesdropper's	judgment	is	correct	–	her	body	of knowledge is incompatible	with the	ball	being	under	cup	1.	According to the	second 8 explanation	her	judgment	is	not	correct	–	the	ball	is	under	neither	cup,	something	that John	is	open	to.	So	the	second	explanation	fares	better. I	propose,	then,	that	the	second	explanation	is	the	correct	explanation	for	why,	in	the original two	cups case, the	eavesdropper is correct to judge 'false'. She is correct to judge 'false' because John's utterance is false, and John's utterance is false for the same	kind	of	reason	that	the	mate's	utterance	is	false	in	the	two	ships	case.	Explaining why	those	utterances	are	false	is	the	objectivity	problem,	and	this	is	indeed	a	problem for	the	standard	account.	But	the	two	cups	case	poses	no	new	problem	to	do	with	the presence of eavesdroppers. So too, I propose, for all of the other cases involving eavesdroppers	that	have	recently	been	discussed	(although	I	won't	justify	that	here). All	the	more	reason,	then,	to	figure	out	a	way	to	solve	the	objectivity	problem. 6.	A	proposal I	will	now	propose	a	modification	of	the	standard	account	that	promises	to	solve	the objectivity	problem	and	explain	the	openness	observation,	and	extends	to	all	kinds	of possibility. It	will	help	to	consider	the	metaphysical	case	first.	About	this	case	it	seems	natural	to say	this:	if	the	die	that	John	used	had	a	'3'	on	each	side,	then	whether	or	not	it	is	true that	John	might	have	rolled	a	'2'	depends	on	whether	or	not	we	can	consider	worlds	in which	John	first	swaps	the	die	for	one	that	has	a	'2'	on	it:	if	we	can	then	it	is	true;	if	we cannot	then	it	is	false.	Might	John	have	rolled	a	'2'?	Not	if	he	was	stuck	to	using	the	die with	a	'3'	on	all	sides.	But	yes	if	he	was	allowed	to	first	swap	it	for	a	regular	die.	We	can think	of	this	in	terms	of	closeness:	whether	or	not	it	is	true	that	John	might	have	rolled a	'2'	depends	on	how	close	to	the	actual	world	are	the	worlds	that	we	can	consider:	if they	can	be	sufficiently	far	away	then	it	is	true;	otherwise	it	is	false. We	seem	to	have	an	intuitive	notion	of	closeness	between	worlds.	Suppose	John	rolls	a die	with a '3' on all sides, and that he rolls a particular '3'. He	might have rolled a different	'3'	with	the	same	die,	so	there	is	a	counterfactual	world	in	which	John	rolls	a different '3'	with	the	same	die.	He	also	might	have	rolled	a '2',	by	first	swapping	the die	for	a	regular	one	and	then	rolling	a	'2',	so	there	is	a	counterfactual	world	in	which John	rolls	a	'2'	with	a	regular	die.	The	first	of	these	counterfactual	worlds	is	closer	to the actual	world than the second is – the second requires a greater deviation from actuality	than	the	first.	Presumably	it is	this	notion	of	closeness	to	which	David	Lewis (1973,	1986	pp.	20-7)	appeals	when	giving	his	account	of	counterfactual	conditionals: 'If it had snowed today then I would have gone skiing' expresses (in my mouth) a proposition	that is	true iff	every	closest	world in	which it	snowed	today is	a	world in which	I	went	skiing.	As	for	'might'	counterfactuals:	'If	it	had	snowed	today	then	I	might have	gone	skiing'	expresses (in	my	mouth)	a	proposition that is true iff some	closest world	in	which	it	snowed	today	is	a	world	in	which	I	went	skiing.	If	the	truth	or	falsity of our utterances of 'If it were the case that A then it	might be the case that S' is sensitive to the closeness	of	worlds, then it	would	not	be surprising to find that the 9 truth	or	falsity	of	our	utterances	of 'It	might	the	case	that	S' (and	'Possibly	S') is	also sensitive	to	the	closeness	of	worlds. With	this in	mind, I	propose	the	following	modification	of the	standard	account (it is the	original	standard	account	with	an	addition,	shown	in	italics): Modified	standard	account An	utterance	of	'Possibly	S'	in	a	context	C	is	true	if	and	only	if	there	is	a	world within	d	of	the	actual	world	(where	d	is	determined	by	C)	in	which	the	prejacent and	the	propositions	in	the	conversational	background	are	all	true. The	idea	is	that	the	context	of	utterance	determines	some	distance	between	worlds,	d. Exactly	which distance this is depends, in part, upon	what the speaker is open to – roughly,	the	more	the	speaker	is	open	to	the	greater	the	distance	she	is	allowing	that the	actual	world	is	from	the	closest	prejacent	world	and	the	bigger	the	value	of	d;	the less	the	speaker	is	open	to	the	less	the	distance	she	is	allowing	that	the	actual	world	is from	the	closest	prejacent	world	and	the	smaller	the	value	of	d.	With	a	distance	d	thus determined,	whether	or	not	the	utterance	of	'Possibly	S'	is	true	depends	not	simply	on whether there is a world in which the prejacent and the propositions in the conversational	background	are	all	true,	but	on	whether	there	is	such	a	world	within	d of the actual world. Thus apart from the compatibility of the prejacent and the conversational	background,	it	also	depends	upon	which	world	is	actual.	This	is	why	the truth	of	an	utterance	of 'Possibly	S'	can	depend	upon	facts	about	the	world	that	are not	known	to	anyone,	and	in	a	way	that	depends	upon	what	the	speaker	is	open	to. How	does	the	modified	account	handle	the	salvage	ship	case?	When	the	mate	asserts, 'It	is	possible	that	the	wreck	is	in	that	bay',	there	is	some	d	such	that	his	utterance	is true	iff	there	is	a	world	within	d	of	the	actual	world	in	which	the	wreck	is	in	that	bay and	everything	that	he	knows	in	the	actual	world	is	true.	The	mate	thinks	that	the	log does	not	rule	out	the	wreck	being in	that	bay,	and	is	not	open	to it	being	otherwise. Because	of	this	d	is	small	enough	that	if	the	log	does	rule	out	the	wreck	being	in	that bay	then	there	are	no	worlds	within	d	of	the	actual	world	in	which	the	wreck	is	in	that bay. Since the log does rule out the wreck being in that bay (as the mate later discovers), there	are	no	worlds	within	d	of the	actual	world in	which the	wreck is in that	bay,	and	so	the	mate's	utterance	is	false. How does the	modified account handle the two cups case (original version)?	When John	asserts,	'The	ball	might	be	under	cup	1',	there	is	some	d	such	that	his	utterance	is true	iff	there	is	a	world	within	d	of	the	actual	world	in	which	the	ball	is	under	cup	1	and everything that he knows in the actual world is true. If John thinks that the ball is under	one	of	the	two	cups,	and	is	not	open	to	it	being	otherwise,	then	John	thinks	that the	actual	world	is	fairly	close	to	a	world	in	which	the	ball	is	under	cup	1,	and	because of	this	d	is	small	enough	that	if	the	ball	is	actually	under	neither	cup	then	there	are	no worlds	within	d	of	the	actual	world in	which	the	ball is	under	cup	1.	Since	the	ball is actually	under	neither	cup,	there	are	no	worlds	within	d	of	the	actual	world	in	which the	ball is	under	cup	1,	and	John's	utterance	is	false.	If	John	is	open	to	the	ball	being under	neither	cup,	then	d	is	large	enough	that	even	if	the	ball	is	actually	under	neither 10 cup	there	are	worlds	within	d	of	the	actual	world	in	which	the	ball	is	under	cup	1.	Since the	ball	is	actually	under	neither	cup,	there	are	worlds	within	d	of	the	actual	world	in which the ball is under cup 1, and since there are some such worlds in which everything	John	knows	in	the	actual	world	is	true,	John's	utterance	is	true.	We	can	thus see	how	the	truth	of	John's	utterance	depends	(a)	on	facts	about	how	the	world	is	that need not be known to anyone at the time of the utterance, and (b) in a way that depends	on	what	John	is	open	to:	the	latter	effects	the	value	of	d,	and	thus	how	close to the actual	world there needs to be a	world in	which the	ball is under cup 1; the former	effects	whether	or	not	there	is	such	a	world. The	explanation	of	each	case	takes	the	same	general	form:	Someone	asserts	'Possibly S';	there is	some	d	such	that	the	utterance	is	true iff	there is	a	world	within	d	of	the actual world in which the prejacent p and the propositions in the conversational background	B are all true; the speaker believes that q is true, and is not open to it being	false,	and	because	of	this	d	is	small	enough	that	if	q	is	actually	false	then	there are	no	worlds	within	d	of	the	actual	world	in	which	p	is	true;	as	it	turns	out,	q	actually is	false,	so	there	are	no	worlds	within	d	of	the	actual	world	in	which	p	is	true,	so	there are	no	worlds	within	d	of	the	actual	world	in	which	p	and	the	propositions	in	B	are	all true, so the	utterance is false;	had the speaker	been	open to	q	being false then the utterance would have determined some bigger distance d+, big enough that the utterance	would	then	have	been	true.	In	the	salvage	ship	case,	S	is	the	sentence	'The wreck	is	in	that	bay'	and	q	is	the	proposition	that	the	log	does	not	rule	out	the	wreck being	in	that	bay;	in	the	two	cups	case,	S	is	the	sentence	'The	ball	is	under	cup	1'	and	q is the proposition that the ball is under cup 1 or cup 2. Nothing in the explanation assumes that the utterance is an epistemic use of 'Possibly S' – the same form of explanation	can	be	used	for	the	metaphysical	and	deontic	cases	above. Thus	with	a simple	and	well-motivated	modification	of the standard	account	we	can solve the objectivity problem and explain the openness observation in a way that extends	naturally	to	all	kinds	of	possibility.4 References De	Rose,	K.	(1991),	'Epistemic	Possibilities',	Philosophical	Review	100,	pp.	581-605. Egan,	A.,	J.	Hawthorne,	and	B.	Weatherson	(2005),	'Epistemic	Modals	in	Context',	in	G. Preyer	and	G.	Peter	(eds.),	Contextualism	in	Philosophy	(Oxford:	Oxford	University Press),	pp.	131-68. Egan, A. (2007), 'Epistemic	Modals, Relativism, and Assertion', Philosophical Studies 133,	pp.	1-22. von	Fintel,	K.	(2006),	'Modality	and	Language',	in	Donald	M.	Borchert	(ed.), Encyclopedia	of	Philosophy,	Second	Edition	(Detroit:	MacMillan	Reference	USA). von	Fintel,	K.,	and	Gillies,	A.	(2008),	'CIA	Leaks',	Philosophical	Review	117,	pp.	77-98. Hacking,	I.	(1967),	'Possibility',	Philosophical	Review	76,	pp.	143-68. Hawthorne, J. (2007), 'Eavesdroppers	and	Epistemic	Modals',	Philosophical Issues	17, pp.	92-101. 4 Thanks	to	Stephen	Kearns,	the	members	of	my	Epistemic	Modality	seminar	at	Cornell	in	Spring	2009, and	an	audience	at	ANU. 11 Kratzer, A. (1977), 'What 'Must' and 'Can' Must and Can Mean', Linguistics and Philosophy	1,	337-55. Kratzer,	A.	(1981),	'The	Notional	Category	of	Modality',	in	H.	J.	Eikmeyer	and	H.	Reiser (eds.),	Words,	Worlds,	and	Contexts:	New	Approaches in	Word	Semantics (Berlin: de	Gruyter),	pp.	38-74. Kratzer,	A. (1991), 'Modality', in	A.	von	Stechow	and	D.	Wunderlich (eds.),	Semantik: Ein	Internationales	Handbuch	der	Zeitgenössischen	Forschung	(Berlin:	de	Gruyter). Lewis,	D.	(1973),	Counterfactuals	(Oxford:	Blackwell). Lewis,	D.	(1986),	On	the	Plurality	of	Worlds	(Oxford:	Blackwell). MacFarlane,	J.	(2008),	'Epistemic	Modals	are	Assessment-Sensitive',	forthcoming	in	B. Weatherson	and	A.	Egan	(eds.),	Epistemic	Modality	(OUP). Teller,	P.	(1972),	'Epistemic	Possibility',	Philosophia	2,	pp.	303-20. Wright, C. (2007), 'New Age Relativism and Epistemic Possibility: The Question of Evidence',	Philosophical	Issues	17.