Monday, November 2, 2009

Evidence: Doxastic or Non-Doxastic?

I haven't given much thought to the question as to whether it is the content of experience or belief that should be our focus in describing the evidence a subject has.

The following seems like a decent principle, the sort of thing that we should be able to accept prior to determining whether to go for a doxastic account or non-doxastic account:

BEBT: If you believe p to be part of your evidence, you believe p to be true.

While that strikes me as a plausible principle (about the evidence you have, not necessarily the evidence there is), it seems to cause trouble for the non-doxastic accounts of evidence.

Let p = there's a dagger before me.

Maybe I don't expect p to be true but I have an experience indistinguishable from one in which I perceive that there's a dagger before me. It seems weird to think that I could say/think rationally/correctly that part of my evidence is that there's a dagger before me, but I don't think there's a dagger before me. It doesn't seem weird to say/think rationally/correctly that I'm having the sort of experience that represents things as if there's a dagger before me but wonder whether there's really a dagger before me.

Maybe BEBT isn't true. Seems true to me. Seems to cause trouble for non-doxastic accounts of evidence.

* Maybe those who identify a subject's evidence with contents of experience can say that the evidence is defeated when the subject believes the experience not to be veridical, but that's not the case I'm imagining. Mine is a case of suspension, not denial.

*Maybe those who identify a subject's evidence with the contents of experience can say that the evidence is possessed only when believed. Okay, but then it's not much different than the doxastic view since possession requires belief and experience.

*Maybe those who identify a subject's evidence with the contents of experience can say that the p's that are our evidence are p's you cannot suspend judgment on when you have the right sort of experience. Maybe when I have the experience of the sort I'm imagining, I can suspend judgment wrt the proposition that there's a dagger before me but not that it appears as if there's a dagger before me. I don't like this move. Even if you think that the content of experience is limited to appearance properties and excludes properties like the property of being a dagger, say, this doesn't report the ascription of sensible qualities or properties to some demonstrable object. It describes how things are with me introspectively and I don't think it's plausible to think that our evidence is limited to these sorts of propositions about how things stand with us as revealed by introspection. Sometimes they include propositions like: that is orange, round, etc... where I can clearly doubt that there's an external object that is picked out because I can wonder whether I'm hallucinating.

5 comments:

Andrew Cullison said...

Here's a counter-example to BEBT that seems pretty good to me.

Suppose Bob believes the following principle:

(EP)If I have evidence for P, then P is part of my evidence (whether P is true or not).

Imagine Bob has a strong seeming that there is a knife in front of him, and he believes that seemings are evidence - but he's still not quite sure if the evidence is strong enough to support believing P.

So he believes he has evidence for the proposition that there is a knife, but does not believe that there is a knife. Given his commitment to (EP) he believes that the proposition that there is knife is part of his evidence.

So...he believes that the proposition that there is a knife is part of his evidence, but he does not believe the proposition that there is a knife to be true.

If I had good reasons to believe something that was in tension with BEBT, then I think I'd give up BEBT in light of the above considerations.

Andrew said...

I forgot to check the "email follow up comments" box. This comments is so I can do that.

Andy

Arturs Logins said...

It seems to me, that there is another possibility here in order to maintain non-doxastic evidence and to reject BEPT.

It seems that BEPT cause trouble for non-daxstic account because it presupose that non-doxastic evidence is propositional evidence. It seems that it is possible to not accept that. We can avoid problems that BEPT causes, if we accept that there could be a non-propositional non-doxastic evidence. In order to do so, we have to accept that: (a) expierence can be evidence, and (b) some kind of direct realism where percieved object is constituve part of expierence.

And to avoid problem caused by the exemple of hallucination, we can accept some kind of disjunctivism and say, that even if this expierence is indistinguishable from percieving digger before me, there are nevertheless two different kinds of mental states - one when I am hallucinating, and the second when I am not. (There are of course plenty of problems for this account, but it is at least possible to argue for it (to say for exemple, that there is a phenomenological difference when one is hallucinating).

Clayton said...

Arturs,

I think that's a good point. I had assumed that evidence is propositional, but maybe the thing is to say that _some_ evidence is propositional and then to be open to a sort of pluralism. Maybe evidence can consist of propositions, states of affairs, daggers, photographs, etc...

Andrew,

I'll need to think about your example more. It seems that Bob would know that the hypothesis that there's no knife is inconsistent with his evidence. Can you rationally believe/think/say:

(1) ~h is inconsistent with my evidence, but I don't believe h.

I'm not sure what to think.

Andrew Cullison said...

I don't think it would be a case where Bob would have to believe that the proposition there's not a knife is *inconsistent* with his evidence.

My idea is that this is a case where Bob suspends judgement about whether or not there is a knife (and let's add to this that he suspends judgment about whether or not his *total* evidence supports the proposition that there is knife)