Every so often I ride past a primary school on my way to the city. (I say this so you don’t think I’m some kind of perverted child-watcher.) Every time, if there are any children out on the oval, at least one is always walking along the line of the fence. I remember people, including myself, do the same in high school: gravitate to the limit of where we were allowed to be. You often see caged animals – other caged animals, I mean – patrol the edges of where they can go. It doesn’t even have to be an artificial cage. Consider the attraction of cliff-top walks, for instance. Like probing at a loose tooth or scratching at a scab, this appears to be a basic animal instinct.
I wonder if much philosophy isn’t doing exactly the same thing. Hume writes about concepts we biologically cannot hold in our minds for long periods of time – the impossibility of identity, the nonexistence of objects – even though he says we can never act on them in practice. Nietzsche thought all metaphysics is a reflection of personality; that the way we think about reality is conditioned not by a drive towards truth but by countless ‘lower’ drives. Perhaps what drives Hume (and many others, before and after) to think along the limits of thought is the same set of drive that causes children to wander along fences.
This ties into the interminable argument about the ‘use’ or ‘value’ of philosophy. Apart from any other considerations, even if everybody were to suddenly become convinced of the practical uselessness of philosophy, I believe people would still be driven to philosophize.