A couple weeks ago, I went to a lecture at the Paulinerkirche given by Professor Timothy Williamson, a philosopher from Oxford, entitled Armchair Knowledge and the Philosophy of Philosophy. The talk was for a general audience, so I am sure Professor Williamson simplified his arguments and glossed over some of the supporting ideas that have helped spur his own, but I still felt somewhat dissatisfied with overall presentation and thrust of his argument.
Professor Williamson started with a description of the general practice of philosophy as an exercise of cogitation one performs from the comfort of an armchair. He then gave a humorous anecdote about an Irish chemist being surprised that English universities regularly also had philosophy departments (the chemist had assumed that Dublin's Trinity College philosophy department continued to exist as a matter of tradition rather than for any sort of pragmatic utility). Thus, Williamson set up the central conflict on which his talk centered as the question of whether or not the criticism of philosophy as antiquated and made obsolete by experimental science was apt, and what that meant for the motivations and practice of philosophy (the philosophy or philosophy, if you will).
The central thrust of Williamson's argument started with the idea that no one is a pure empiricist, as basing all of one's beliefs on direct empirical evidence is impossible. In this, Williamson is certainly correct. Earning one's education is in many ways an exercise in academic trust, although, as was astutely pointed out in the How To Think About Science series, one of the inherent strengths of science rests not so much with its skeptical roots as with its ability to determine who and what to trust. One of the problems I continually run into in subjects outside of the realm of science (and even within some discourse that claims it is scientific - namely certain branches of psychology) is that the established basis for some discourse is not clearly defined or, in some cases, is clearly defined but erroneous (either in light of later discoveries, in which case it may be excusable, or simply because it was assumed true without empirical evidence, in which case it is less excusable). For example, as those who remember my reviews of a selection of historical treatises on political theory may recall, I was thoroughly disappointed with both Plato and Aristotle. I thought Hobbes did a much better job by specifically and carefully defining his terms and assumptions (some might claim that this was a little overly pedantic on his part, making his text more difficult to digest than one which skips over such dry discourse as careful definitions, but it is important nonetheless). Of course, I think Hobbes' analysis still ends up flawed, but it is much easier to follow his reasoning and in that way determine where I disagree thanks to his methodological approach. I seem to be getting away from myself, however. Getting back to Williamson's talk, I grant that calling for a purely empirical framework for knowledge and belief is not feasible. We do choose to trust knowledge disseminated by other sources, but I think the important point here rests on our determination of the trustworthiness of sources. Basing trust on human charisma, while often the most common method, is unfortunately a highly flawed method as it easily leaves one open to being taken advantage of. The system created around unbiased and rigorous verification of knowledge rooted entirely within the natural world that is modern science is the best that I think we can currently hope for in the department of trust.
Continuing from the fact that everyone accepts knowledge not personally empirically derived, Williamson also brings up the fact that even empirical scientists further process empirical results with a set of mental reasoning tools which Williamson classified as akin to imagination. We are mentally capable of trying out ideas and following avenues of thought which have not explicitly been borne out in the real world. At this point, Williamson went on a slightly odd detour by ruminating on the origins of the human capacity for reasoning given our evolutionary past. He justified its survival advantage by giving an example of a person running from a tiger - the person would be able to gage the appropriate response by running through possible future scenarios in their mind (such as hiding behind a rock, climbing a tree, and so on). Of course, it was a simplistic example, so I won't spend too long quibbling with it, but I do want to point out that any person who stopped to think so carefully while being chased by a tiger was going to be caught and eaten. Our capacity for rational thought serves more to modulate what sorts of behaviours we practice to increase our future survival capacity rather than serving us in speedy split-second survival decisions. Ignoring that nuance for the sake of the argument, however (and it does not particularly change the logic to go from reasoning about what sorts of behaviours are best to practice for future enactment and what sorts of behaviours one should execute in the current moment), it is true that we continually process empirical information (often in ways we are not even immediately aware of - see my series on top-down processing in vision).
Essentially, those two points are what led Williamson to his justification for philosophy. Philosophy is therefore, according to my understanding of Williamson, simply engaging our capacity of hypothetical rational thought as a valid exercise in knowledge derivation. I would contend, however, that Williamson's version of philosophy is continuous with and enveloped by the combined fields of mathematics and science, and the areas of philosophy that remain outside of those fields still have no valid justification as sources of worldly knowledge. As I see it, there are two possible ways in which one can engage the rational faculties that Williamson established to exist. One can ruminate on the purely abstract, such as the field of logic. Philosophy of that sort, however, becomes indistinguishable from the field of mathematics. It can be a valuable avenue of thought, but it does not tell us directly about the world. When philosophy moves beyond the abstract and begins to make statements about reality, then I think it should be held to the same empirical accountability as any theoretical science. Philosophers may not be the ones gathering the empirical data, but that does not excuse them from being aware of the implications of that data. Far too often people entirely ignorant of neurophysiology and even behavioural psychology embark on developing vast treatises of the philosophy of the mind. Of course, philosophers often focus on different questions and aspects of a field, and in that I think they make their most valuable contributions (for example, fields like the philosophy of physics or the philosophy of mathematics, which often draw upon the larger philosophical field of epistemology, are exceedingly important for any scientific field and, in the same way that I think philosophers should make an effort to be aware of at least general trends of empirical results, so too should more scientists be aware of the philosophical underpinnings of their fields). Fundamentally, though, all knowledge of our world is rooted in empirical data, and thus I think the philosophy of philosophy leads us to the same place as the philosophy of science and mathematics.