Saturday, 12 May 2007

Strongly Believe vs. Weakly Believe

Note: This post was originally composed as a reply to Rachael's insightful comments in response to my post, “Probable But Unjustifiable”, over at the Web of Belief. The proposal I canvas is still rough and needs further ironing out. Any feedback is greatly appreciated.

Occasionally, we use “I believe” to identify something we are certain about. For example, I believe that I am now thinking. Sometimes we use ‘I believe’ to describe something we are intellectually/ rationally/ doxastically committed to. For example, I believe that 1 + 1 = 2. Often we use ‘I believe’ to identify something we take ourselves to know. I believe I'm currently looking at a computer monitor. This is also something that I know! However, we frequently use ‘I believe’ to indicate something we merely hold to be likely. Consider the following exchange:
A: “Is it 2:30pm yet?”
B: “I'm not sure, but I believe it is.”
B seems like a perfectly natural thing to say (though on at least one reading of “believe” it would be self-contradictory). I take B to express something along the following lines:
B*: “I'm not sure, but it seems likely.”
Thus, often when we say that we believe that p, we simply mean that we hold p to be likely or as having a high probability of being true. However, this cannot be the notion of belief that factors into a JTB account of knowledge since to know something we must be sure about it, and not merely think it likely. (Consider, for example, the contrast between merely believing your ticket will lose (read: likely to lose) and actually knowing that your ticket has lost after the results of the drawing have been announced.) If I am right that knowing p requires that one be intellectually/ rationally/ doxastically committed to p (rather than being committed to p being merely likely) the type of belief that factors into a JTB account of knowledge must implicate intellectual commitment to the truth of p.

There is, of course, an alternative way of construing the present debate (inspired by one reading† of McDowell's disjunctivism): To simply dispense with the JTB account altogether and offer a disjunctive analysis of knowledge and belief. On the disjunctive view one either knows that p or merely believes that p. The former is factive while the latter is evidential and probabilistic, and there is no common factor shared between the two. More precisely, knowledge is not to be understood as a special kind of belief or belief plus something else (e.g., justification and truth).

There are at least three objections to the disjunctive approach to knowledge and belief. First, the knowledge/belief disjunction seems out of step with how we normally speak. For example, how are we to reconcile the claim that we either (exclusively) know that p or believe that p, with the datum that we often say we believe things that we also take ourselves to know.

Second, it seems to present a problem for the intuition that known propositions can be justified. It is a necessary condition of a proposition being justified (as opposed to merely being justifiable) that a subject have some justification for believing the proposition. But while it makes sense to talk about someone having justification for believing that p, it does not make sense to talk about someone having justification for knowing that p. (For example, seeing that p may constitute justification for believing that p, but it does not constitute justification for knowing that p.) The latter (i.e., justification for knowing that p) would be a type of category mistake. “Knowing” simply is not the sort of thing one could conceivably have justification for. Now, if we keep believing as a constituent of knowing (à la JTB), then we may continue to hold that known propositions are justified since the believing implicated in the knowing is justified. However, once we chuck believing as a constituent of knowing, there is nothing left to be justified. Thus, we would be forced to conclude that known propositions are not justified.

Third, once we have renounced the idea that believing is a constituent of knowing it becomes unclear how we are to bridge the gap between being in a position to know that p and actually knowing p. This objection is particularly pertinent to McDowell's epistemology-oriented disjunctivism (in contradistinction from, say, Snowdon's perception-oriented disjunctivism). According to McDowell's epistemic disjunctivism, perceptual experiences (i.e., the good case) put a subject, S, in the position to know that p, but it does not actually confer knowledge on S. (See: McDowell's “Criteria, Defeasibility and Knowledge” fn 37.) McDowell stresses that it is important to keep the two separate since there may be situations in which a subject is in a position to know that p, but still fails to know that p. For example, imagine a subject with perfectly reliable vision, who (for some unknown reason) took her vision to be unreliable. (Perhaps she was tricked into believing that her coffee was spiked by a powerful hallucinogen.) In such a case, the de facto reliability of the subject's visual experience would put her in a position to know that p, but her belief that her vision was unreliable would prevent her from having knowledge. Now, the question is, what bridges the gap between a subject merely being in a position to know that p and her actually knowing that p?

I submit that this is where believing (as intellectual commitment to p being true) comes in. It is only when we adopt an attitude of belief towards p that we cross over from merely being in a position to know that p to actually knowing p. Absent the attitude of belief, we may continue to have p among our mental contents (and thus be in a position to know that p) but we would not know that p. In order to know that p, one must take a stand on p; one must be intellecutally/ rationally/ doxastically committed to the truth of p. Thus, believing p is indispensable for knowing p.

My proposal:
As an alternative to the knowing/believing disjunction I propose that a distinction be made within the concept of believing itself, what I will refer to as strongly believe and weakly believe. To strongly believe that p entails that a subject is intellectually/ rationally/ doxastically committed to p being true. To weakly believe that p entails that a subject is intellectually/ rationally/ doxastically committed to p being likely or highly probable. The primary goal of my distinction between strongly believing and weakly believing is to make sense of the different uses of “believe” in our ordinary speech. However, it is also an interesting question whether the proposed distinction may have implications for problems related to the concept of justification as well. This is a possibility I hope to explore in greater detail in the near future. But for the time being, the central contention of this post may be summarised as follows: To the extent that we are concerned with knowledge (i.e., true justified belief), it is belief as intellectual commitment to the truth of p that is at play. Thus, for a subject to know that p she must also strongly believe that p.

†This particular reading of McDowellian disjunctivism is implicit in Charles Travis' paper, “A Sense of Occasion”.


Still confused said...

Loved the blog. I think part of the difficulty with belief is that in the English language there's no way to distinguish between strong and weak belief. I wrote a blog about it, and I tagged you. It's not as intellectual as yours but you might get a laugh.

How's it in the Uk anyway? I miss it so.

Chris said...

I believe this is an excellent post;)

Here via blogexplosion but will definitely be back!

Have a great weekend!
My Blog


Still confused,
I checked out your post. You give a very interesting spin to my weakly believe vs strongly believe idea.


Thanks Chris!