Let me recycle the line of response that I gave to a slightly different earlier question, with a few tweaks (and not disagreeing with my co-panelist, but with different emphases). It is a truism that, when I fully act, it is as a result of my desires, my intentions, my goals. After all, if my arm moves independently of my desires, e.g. because you want it to move and push it, or as an automatic reflex, then we'd hardly say that the movement was my action (it was something that happened to my body, perhaps despite my wishes). But note that even if everything I genuinely do (as opposed to undergo) is as a result of my desires etc., it doesn't follow that everything I do has an egoistic motive in the sense of being motivated by the thought that what I do has a payoff for me or that "the choice is best for [me]". The fact that a desire is my desire doesn't entail that the desire is about me or is about some payoff for me, or something like that. And it is just false that all my desires are...

What on earth is irrational about being curious about the current state of play in the foundations of quantum mechanics, about loving your beautiful, clever, affectionate daughter, about being bored by mindless chatter about C-list celebrities, about feeling fear when an errant car suddenly hurtles into your path, about being indifferent when picking one from a shelf of ten identical and equally conveniently placed packets of cereal in the supermarket, about being excited at the prospect of going to New York for the first time, about wanting to return to Venice? None of these strike me as in the slightest bit irrational! Rather they seem entirely rational and reasonable responses in any normal sense of 'rational' (indeed, it would be pretty unreasonable not to have most of them). So the original question seems misplaced in so far as it presupposes that such responses must indeed be "irrational". Perhaps though the point behind the question is this. If you use ...

Jennifer Church points out a couple of types of a case where irrationally formed beliefs (or degrees of belief, in the over-confidence case) can promote our welfare. Sure there are such cases. But that doesn't affect the original point at stake. There being a few cases doesn't undermine the point that in general false beliefs (because of their content!) are unlikely to lead to successful action,* and so irrationally formed beliefs -- being likely to be false -- are not in general likely to lead to actions which get us what we want. And that is enough to explain why we should in general care a lot about forming our beliefs in a rational way. Which in turnis enough to counter the original questioner's worry that philosophy"uses as its main tool a mechanism [rational thought] that is theopposite of what is most important to us": in general ,rational belief-formation matters for getting whatever is important tous. *Indeed, some attractive views about ascribing content to belief...

Just a footnote to Mark Collier's helpful post. I actually said that irrationally formed beliefs are not likely to lead to actions which get us what we want (rather than cannot get us what we want). And that claim is enough to explain why we should in general care a lot about forming our beliefs in a rational way . Which in turn is enough to counter the original questioner's worry that philosophy "uses as its main tool a mechanism [rational thought] that is the opposite of what is most important to us": in general , rational belief-formation matters for getting whatever is important to us. Even if pockets of irrationality, episodes of self-deception, etc. can -- by good fortune -- happen to promote our welfare.

There is a number of issues raised here. Let me make just two points. First, on the specific idea that "perhaps what we think is universally true is not, we’resimply programmed to think it is? ... that’d be a profoundlyeffective evolutionary tool for preservation of the species." But of course, if we were programmed to believe falsehoods , that would not in general promote survival. To get food, for example, we basically need true beliefs about where it is to be found. Of course, this isn't to say that we need always get things right: it might be that evolution has provided us with quick-and-dirty information processing capacities that deliver true beliefs often enough to promote survival. But the point remains that what promotes survival is a sufficient number of true beliefs. So the thought that our beliefs are generated by mechanisms provided by our evolutionary history cannot by itself be a reason for across-the-board distrust. Secondly and more generally, why should we...