There was a decent column on NYT's The Stone blog today. Yeah, I was surprised too. Robert Burton, a neurologist, neuroscientist and popular science author was discussing the problem that Philosophy has letting go of Reason:
Going forward, the greatest challenge for philosophy will be to remain relevant while conceding that, like the rest of the animal kingdom, we are decision-making organisms rather than rational agents, and that our most logical conclusions about moral and ethical values can’t be scientifically verified nor guaranteed to pass the test of time.
Burton makes some good points in the piece, but he doesn't offer a lot in the way of solutions. It might be fun to think about what a solution would look like.
Like so many of the misconceptions that Philosophy can't seem to get past, I'm inclined to lay this one at the feet of Immanuel Kant, who probably did as much to send Philosophy veering off in the wrong direction as Freud did for Psychology.
Without getting long-winded about it, Kant was keen to refute Hume's conclusion that inductive reasoning from experience was the only way we really acquired knowledge. To attack the problem, Kant separated judgements along two axes: the a priori/a posteriori axis and the analytic/synthetic axis. The distinction between a priori and a posteriori is that the former takes place "prior to experience" and the latter are grounded in experience. The difference between analytic and synthetic judgements is that the former work only with information present in the propositions being reasoned about and thus don't create "new" knowledge, while the latter bring new information in. Kant combined these axes to produce four kinds of judgements: a posteriori analytic, a posteriori synthetic, a priori analytic, and a priori synthetic. The kind of judgement which Kant felt would refute Hume, if it existed, was the a priori synthetic judgement. If we could reason, without reference to experience, in a way that would produce new knowledge, Hume's depressing thesis would be wrong.
The fact that of his four categories, one – a posteriori analytic judgements – couldn't exist, and another – a priori synthetic – didn't obviously exist should have been a red flag that he was thinking about it wrong. But maybe we should cut him a break. My sense, after reading a lot of philosophy from this time period, is that the concept of "experience" was not particularly clear or well-formed. The ghost of Avicenna's Floating Man was still pretty regularly rattling windows and knocking things off Philosophy's bookshelves in Kant's time (hell, he's still kicking around today).
A modern, physicalist view would reject the a priori/a posteriori distinction altogether. Avicenna's Floating Man would have a brain with zero input, and we know that such a brain would probably not operate at all, let alone do any predicate logic. Thought itself – including reason – is driven by stimulus, and there is no real way to separate perception from reasoning, except with respect to a rough taxonomy of mental activity. Both reason and perception depend upon the patterned activity of a brain impinged upon over long periods of time by a consistent physical universe that enables it to transcode, record and model its consistencies.
When Burton talks about the "void" that would be left in Philosophy if reason were abandoned, I'm reminded of the fear of nihilism that lurks behind arguments for moral realism. If there is no real foundation for moral truths, it whispers, then the whole ediface falls and we are left with a morality in which "anything goes". It's the same fear that Camus walked right up to and flipped the bird at in his discussion of absurdity. And it was a bird that needed flipping.
It's not really Reason that's losing its footing in Philosophy. It's not just a perception problem. It's realism.
The fact is that the nihilism of "anything goes" is a false fear. Anything doesn't go. Anything hardly even gets started going. Our physical universe constrains us to a knife's edge of possibilities, and our biological structures constrain us even further. We can't escape the survival instinct or our range of tastes any more than we can escape gravity or the temperature range our bodies can withstand.
So the solution to Philosophy's problem is a weaker, less absolute concept of reason, and a weaker, less absolute realism that recognizes that what we wanted to be a foundation is really just a strong, consistent, persistent set of constraints.