The impossibility theorems...show...that no measure of coherence is truth conducive even in a weak ceteris paribus sense, under the favorable conditions of (conditional) independence and individual credibility.
- Erik Olsson, SEP entry on Coherentist Theories of Epistemic Justification
This discussion on moral disagreement got me thinking again about the issue of philosophical progress, and the extent to which we should be confident that philosophy is at all truth-conducive. Most of us, presumably, go about our careers thinking that philosophy bears some relation to truth: that it 'isn't all B.S.', as some of our students cheerfully maintain. Yet some philosophers demur, questioning whether philosophy makes any progress or whether we have any reasons to consider it truth-conducive.
Sometimes it is not hard (for me, at any rate) to fall back into these worries myself. For, what do we have really to go on, as philosophers? Scientists, of course, can point to hard data: to experiments that anyone can verify (that is, which result in the same observations, more or less no matter who runs the experiment). Philosophy, however, is not based on such data--for, as we all well know, philosophical premises "that more or less everyone accepts" are nearly-impossible to come by. Premises that "seem true" to one philosopher often seem "obviously false" to others. And yet, or so it seems, that is all we can fall back on: on how things seem to us, that is, "our intuitions" or "our considered philosophical judgments"...this despite the fact that, again, things "seem" very different to different inquirers.
And no, I do not think we should be very impressed by "how common" an intuition is, or even that something like 100% our students think that killing innocent people is wrong. For again, the mere fact that something "seems" a certain way to lots of people doesn't make it true (or even, I might add, likely to be true). All it shows is that particular belief is common in a given population (and, for what it is worth, there seem to be significant populations of people in this world--now and throughout history--who don't "see the wrongness of killing innocent people"). Finally, while we can of course pursue the philosophical project of "rendering our beliefs" more coherent--in a kind of reflective equilibrium--there are very strong arguments that coherence isn't truth conducive.
Finally, setting all of these particular concerns aside, there is the rather disturbing fact of "dissensus": that fact that when we look at the philosophical landscape--at the incredibly disparate views that different professionals defend, and immense of lasting disagreement over arguments, premises, etc.--we do not anything like a picture of convergence on "known truth" (as we see in most the sciences, where there are basically consensus views, based on firm data, on a lot of stuff). We see persistent disagreement on very basic questions--new arguments based on premises that "seem plausible" to some but not to others--rinse, and repeat.
How do you respond--in your own mind, or to your students--to these kinds of worries? Should we think that philosophy has any truth-conduciveness at all? On what grounds? Or, should we perhaps conceive the proper purpose of philosophy as something else, say "understanding" (though it is a bit hard to--cough--understand what that might amount to without truth-conduciveness!). I'm curious to hear what you all think!