October 04, 2006

The Most General Factive Mental State Operator

Last week I re-read the first chapter of Timothy Williamson's Knowledge and Its Limits. TW argues that 'knows' is the most general factive mental state operator. To be a factive mental state operator (FMSO) is to be a factive semantically unanalyzable expression that attributes a propositional attitude to a subject. The semantic unanalyzability claim is that, by definition, an FMSO is never synonymous with a complex expression whose meaning is composed of the meanings of its parts. So, for instance, 'could hear' is a FMSO. There is a reading of it such that the presumption of truth is not cancelable, as is revealed by the deviance of


(1) She could hear that the volcano was erupting, but it was not erupting.


Moreover, the meaning of 'could hear' is not composed of the meanings of 'could' and 'hear', for that would assimilate 'could hear' to something like 'it is merely possible that s heard that p', which is not factive.

Additionally, 'could hear' is further evidence that 'knows' is the most general FMSO, since 's could hear that p' implies 's knows that p'.

Let's explore the properties of other FMSOs. I want to argue that there is a more general FMSO than 'knows'.

Consider the ambiguity in each of the following expressions:

'could see that'

'could hear that'

'could feel that',


'can't believe that'

'is not happy that'

'is not surprised that'

'failed to realize that'

'is not impressed that'

'is not able to taste that'

Each of these has a factive and a non-factive reading. For instance, 'cannot believe' is factive in

(2) I cannot believe that you are smoking again,

but is not factive in

(3) I cannot believe that I don't have any beliefs.


Now the non-factive readings of the above list items are semantically decomposable. They may be paraphrased roughly as


'it is false that s believes/is happy/is surprised/realizes/is impressed/is able to taste that'

or

'it is (merely) possible that the subject s sees/hears/feels that'.



Exactly analogous remarks may be made about knowability- and ignorance-attributions. More carefully, 'could have known that' and 'does not know that' both have a factive and a non-factive reading. Let's discuss 'could have known that'. The non-factive reading, perhaps not common in ordinary English, is that it is merely possible that s knows that p. The other reading carries a presumption of truth as in 's was in a position to know that p'. Notice that the presumption of truth is not cancelable. This is demonstrated by the deviance of the following claims:


(4) Andy could have known that grandmother was ill, even though she was not ill.

and

(5) Sally was in a position to know that Andy was cheating, but he was not cheating.

The deviance of the claims suggests that the presumption of truth is semantic and not cancelable.

As with the factive readings of the items on the above list, we should expect that the factive readings of 'could have known that' and 'is not known that' are not analyzable. My hypothesis is that they are not analyzable. And I suggest that the burden is on one who thinks otherwise to show that 'could have known' is different from all of our other factive operators of the form 'could have ___ed'.

Incidentally, the non-factive readings of all of the aforementioned expressions fail to attribute a propositional attitude to a subject. They either outright deny the presence of the attitude or affirm merely its possibility of obtaining. The factive readings of the above operators, on the other hand, all attribute a propositional attitude to a subject (with the exception of 'does not know that').

According to Williamson, when a propositional attitude that p is attributed, so is a grasp of the concepts in p. Since the factive reading of 'does not know' fails to attribute grasp of meaning, we may conclude that it is not a mental state operator. A fortiori it is not an FMSO. Importantly, 'could have known' does attribute grasp of meaning. Consider,

(6) Andy doesn't understand high-energy physics, yet he could have known that there are top quarks in pp collisions.

Or

(7) Andy doesn't grasp any of the rules of Chess. He was nevertheless in a position to know that his King was about to be mated.

The oddities of (6) and (7) suggest that knowability is a mental state---that 'to s it is knowable that p' implies 's has an attitude that p'---minimally, it implies 's grasps the meaning that p'. Similar things can be said about 's failed to realize that p'. It wouldn't be a failure to realize that p, if the subject didn't have a grasp of the concepts in p.

It would seem then that 'knowable' or 'could have known' is an FMSO. The problem for Williamson's account is that 's could have known that p' does not entail 's knows that p'. Hence, 'knows' is not the most general FMSO. Instead, the entailment goes the other way. Are we to conclude that 'could have known' is the most general FMSO?

10 comments:

Julien Murzi said...

This is thoughtful and provoking. For now, just a question of clarification, if I may.

"More carefully, 'could have known that' and 'does not know that' both have a factive and a non-factive reading."

I can't see the factive reading of not-Kp, right now. Am I missing something?

Best,

J

Joe said...

Consider,

"He doesn't know that his wife died in the plane crash."

The presumption of truth here is not cancelable. Evidence for this is the fact that the following is deviant:

"He doesn't know that his wife died in the plane crash. However, his wife is alive and well."

Julien Murzi said...

Thanks much, Joe.

Perhaps "he doesn't know that his wife died in the plane crash" in fact shorthand for "his wife died in the plane crash, but he doesn't know it".

Carrie (Jenkins) made this point to me, in St Andrews. One should perhaps rule out conversational implicature hypotheses before claiming that some instances of the relevant expressions are factive.

As far as 'not-Kp' is concerned, I think I would opt for the implicature option. But I still don't know what to think about knowability itself. Your examples seem compelling.

Best,

J

Jeremy Fantl said...

Hi Julien,

I took Joe's point about uncancellability to be evidence against the implicature option. But I shouldn't speak for Joe, here.

-Jeremy

Joe said...

Thanks Julien and Jeremy. My point about uncancellability was meant to be evidence against the implicature option. But I think there is a worry here nevertheless. I'm claiming that 'does not know' is ambiguous between a factive and a non-factive reading. The other possibility is that there is no ambiguity and that the apparent factivity can be explained by implicature. I believe that there is some worry about how effective an uncancellability argument can be when there is a presumption of ambiguity. However, I think the onus is on who thinks that there is an implicature. Which Gricean principles explain the presumption of truth in 'does not know'? Moreover, notice it is not enough to tell a Gricean story. One must also give reason for thinking the Gricean account is more plausible than the semantic account.

Anonymous said...

Joe,

You say that ‘could have known that’ has two readings: a factive and a non-factive reading. The non-factive reading, you say, “is that it is merely possible that s knows that p.” On the factive reading, you say the presumption of truth is not cancelable because it implies s was ‘in a position’ to know that p.

I suppose I’m not sure why being in a position to know that p implies p. Suppose I observe a man fall off a very high bridge. It is nearly impossible that a man who falls off this bridge will survive the fall. Accordingly, I believe this man is dead. Now, supposing the man survives, it seems that my epistemic position is such that, had he died, my belief that he had died would have qualified as knowledge. Accordingly, it seems I ‘could have known that’ he died in the sense that I was ‘in a position to know’ that he died. The only reason I didn’t know he died was the fact that he didn’t die. In other words, it seems there are two ways to be in a position to know p while not knowing p: (i) p is true, and the only thing s needs in order to know p is the belief that p; or (ii) s (rationally) believes p while p is false; had p been true, s would have known p. In both (i) and (ii), it seems s is in a position to know p, but fails to know p.

Now, you want to say a subject can only be in a position to know p in the sense of (i). I think you need to argue for this. As it stands, it seems equally reasonable for a person to say a subject is in a position to know p in either of the senses I’ve just outlined ((i) or (ii)). Accordingly, it seems that you haven’t offered an account of ‘could have known that’ that is factive.

Regards,
John

Anonymous said...

As for the possibility of a Gricean explanation of the presumption of truth in the 'does not know' case. Maybe something like this is not entirely implausible:

Since 'it is false that p' is stronger than and trivially entails that 'John does not know that p' (how could he? it's false!), uttering the latter sentence while the former is known/believed to be true arguably violates the quantity principle. You're less informative than you could be with respect to conversationally relevant facts.

S.

joe said...

That is a good explanation. It would explain the presumption of truth. But then we should be able to cancel the implicature with a claim like, "Harold doesn't know that his wife is dead, but she isn't dead." The claim sounds deviant. And so, the presumption of truth is not canceled. 'does not know' passes the semantic test.

Anonymous said...

Another try for cancellation:

Suppose Ann and Ben and Carl play a game: One makes a claim, the others have to come up with a claim that is entailed by it. Whoever is first, wins. Carl claims: It is false that p. Ann, having just finished her first lesson in epistemology, wins with the claim: Ben does not know that p. Here, I think, the context cancels the truth-presumption.

S.

joe said...

I'll buy that. I think there are factive and a non-factive readings of 'doesnt know'. If that's right, then the former may be unanalyzable, while the latter is the truth functional denial of 'it is known that'.