What is philosophy? Is it largely a grand waste of time, as some scientists (like Peter Atkins and Stephen Hawking) suppose? Here’s an extract from a forthcoming publication of mine…
On my view, philosophical questions are for the most part conceptual rather than scientific or empirical and the methods of philosophy are, broadly speaking, conceptual rather than scientific or empirical.
Here’s a simple conceptual puzzle. At a family get-together the following relations held directly between those present: Son, Daughter, Mother, Father, Aunt, Uncle, Niece, Nephew, and Cousin. Could there have been only four people present at that gathering? At first glance, there might seem to be a conceptual obstacle to there being just four people present – surely, more people are required for all those familial relations to hold between them? But in fact the appearance is deceptive. There could just be four people there. To see that there being just four people present is not conceptually ruled out, we have to unpack, and explore the connections between, the various concepts involved. That is something that can be done from the comfort of your armchair.
Many philosophical puzzles have a similar character. Consider for example this puzzle associated with Heraclitus. If you jump into a river and then jump in again, the river will have changed in the interim: the water will have moved, the mud changed position, and so on. So it won’t be the same. But if it’s not the same river, then the number of rivers that you jump into is two, not one. It seems we’re forced to accept the paradoxical – indeed, absurd – conclusion that you can’t jump into one and the same river twice. Being forced into such a paradox by a seemingly cogent argument is a common philosophical predicament.
This particular puzzle is fairly easily solved: the paradoxical conclusion that the number of rivers jumped into is two not one is generated by a faulty inference. Philosophers distinguish at least two kinds of identity or sameness. Numerical identity holds where the number of objects is one, not two (as when we discover that Hesperus, the evening star, is identical with Phosphorus, the morning star). Qualitative identity holds where two objects share the same qualities (e.g. two billiard balls that are molecule-for molecule duplicates of each other, for example). We use the expression ‘the same’ to refer to both sorts of identity. And each kind of identity can hold without the other (our two billiard balls are numerically identical but not qualitatively identical, and numerically the same ball may later be qualitatively different from how it is now). Having made this conceptual clarification, we can now see that the argument that generates our paradox trades on an ambiguity. It involves a slide from the true premise that the river jumped in the second time isn’t qualitatively ‘the same’ to the conclusion that it is not numerically ‘the same’. We fail to spot the flaw in the reasoning because the words ‘the same’ are used in each case. But now the paradox is resolved: we don’t have to accept that absurd conclusion. Here’s an example of how, by unpacking and clarifying concepts, it is possible to solve a classical philosophical puzzle. Perhaps not all philosophical puzzles can be solved by such means, but at least one can.
So some philosophical puzzles are essentially conceptual in nature, and some (well, one at least) can be solved by armchair, conceptual methods.
Still, I have begun with a simple, some might say trivial, philosophical example. What of the so-called ‘hard problems’ of philosophy, such as the mind-body problem? The mind-body problem, or at least a certain versions of it, also appears to be essentially conceptual character. On the one hand, there appear reasons to think that if mental is to have causal effects on the physical, then it will have to be identical with the physical. On the other hand, there appear to be conceptual obstacles to identifying the mental with the physical. Of course, scientists might establish various correlations between the mental and the physical. Suppose, for the sake of argument, that science establishes that whenever someone is in pain, their C-fibres are firing, and vice versa. Would scientists have then established that these properties are one and the same property – that pain just is C-fibre firing – in the way they have established that, say, heat just is molecular motion or water just is H2O? Not necessarily.
Correlation is not identity. And it strikes many of us as intuitively obvious that pain just couldn’t be a physical property like C-fibre firing – that these properties just couldn’t be identical in that way. Of course, the intuition that certain things are conceptually ruled out can be deceptive. Earlier, we saw that the appearance that the concepts son, daughter, etc. are such that there just had to be more than four people at that family gathering was mistaken: when we unpack those concepts and explore the connections between them it turns out there’s no such conceptual obstacle. Philosophers have attempted to sharpen up the common intuition that there’s a conceptual obstacle to identifying pain with C-fibre firing or some other physical property into a philosophical argument. Consider Kripke’s anti-physicalist argument, for example, which turns on the thought that the conceptual impossibility of fool’s pain (of something that feels like pain but isn’t because the underlying physical essence is absent), combined with the conceptual possibility of pain without C-fibre firing (I can conceive of a situation in which I think I am in pain though my C-fibres are not firing), conceptually rules out pain having C-fibre firing as an underlying physical essence (which it would have if the identity theory were true).  Has Kripke identified a genuine conceptual obstacle? Perhaps. Or perhaps not: perhaps it will turn out, on closer examination, that there is no such obstacle here. The only way to show that, however, will be through
logical and conceptual work. Just as in the case of our puzzle about whether only four people might be at the family gathering and the puzzle about jumping into one and the same river twice, a solution will require we engage, not in an empirical investigation, but in reflective armchair inquiry. Establishing more facts about, and a greater understanding of, what happens in people’s brains when they are in various mental states, etc. will no doubt be scientifically worthwhile, but it won’t, by itself, allow us to answer the question of whether there is such a conceptual obstacle.
So, many philosophical problems – from some of the most trivial to some of the hardest – appear to be essentially conceptual in nature, requiring armchair, conceptual work to solve. Some are solvable, and indeed have even been solved (the puzzle about the river). Others aren’t solved, though perhaps they might be. On the other hand, it might turn out that at least some philosophical problems are necessarily insoluble, perhaps because we have certain fundamental conceptual commitments that are either directly irreconcilable or else generate unavoidable paradoxes when combined with certain empirically discovered facts.
So there are perfectly good questions that demand answers, and that can in at least some cases be answered, though not by empirical means, let alone by the very specific mode of empirical investigation referred to as ‘the scientific method’. In order to solve many classic philosophical problems, we’ll need to retire not to the lab, but to our armchairs.
But is that all there is to philosophy? What of the grander metaphysical vision traditionally associated with academic philosophy? What of plumbing the deep, metaphysical structure of reality? That project is often thought to involve discerning, again by armchair methods, not what is the case (that’s the business of empirical enquiry) but what, metaphysically, must be so. But how are philosophers equipped to reveal such hidden metaphysical depths by sitting in their armchairs with their eyes closed and having a good think?
I suspect this is the main reason why there’s considerable suspicion of philosophy in certain scientific circles. If we want to find out about reality – about how things stand outside our own minds – surely we will need to rely on empirical methods. There is no other sort of window on to reality – no other knowledge-delivery mechanism by which knowledge of the fundamental nature of that reality might be revealed.
This is, of course, a traditional empiricist worry. Empiricists insist it’s by means of our senses (or our senses enhanced by scientific tools and techniques) that the world is ultimately revealed. There is no mysterious extra sense, faculty, or form of intuition we might employ, while sat in our armchairs, to reveal further, deep, metaphysical facts about external reality.
If the above thought is correct, and armchair methods are incapable of revealing anything about the nature of reality outside our own minds, then philosophy, conceived as a grand metaphysical exploration upon which we can embark while never leaving the comfort of our armchairs, is in truth a grand waste of time.
I’m broadly sympathetic to this skeptical view about the value of armchair methods in revealing reality. Indeed, I suspect it’s correct. So I have a fairly modest conception of the capabilities of philosophy. Yes, I believe we can potentially solve philosophical puzzles by armchair methods, and I believe this can be a valuable exercise. However, I’m suspicious of the suggestion that we should construe what we then achieve as our having made progress in revealing the fundamental nature of reality, a task to I which suspect such reflective, armchair methods are hopelessly inadequate.
 Saul Kripke, Naming and Necessity (Oxford: Wiley-Blackwell, 1991), Lecture III.