Critics of contemporary metaphysics might have moved on from logical empiricism but the accusation that metaphysics is a waste of time has not gone away. Those like Craig Callender argue that this branch of philosophy asks irrelevant questions and answers them with unreliable intuitions. But this ignores the role of arguments in metaphysics as well as the crucial, real-world applications of its seemingly strange subject matter, writes Alexander Kaiserman.

It’s not easy to say what metaphysics is, much less what it ought to be. Most branches of philosophy are named after their subject matter – philosophy of mind, philosophy of language, and so on. The word ‘metaphysics’, by contrast, is derived from the collective title given to fourteen books by Aristotle 100 years after his death, probably as a warning from the editor that they should be tackled only after having mastered the books contained in what we now call Aristotle’s Physics. Indeed it’s not clear that metaphysics even has a subject matter as such, seeing as for anything that might be said to be its subject matter (essence, structure, etc.), denying the existence of that thing would itself be considered a metaphysical view.  

Perhaps because of this, metaphysics has often been a target for those harbouring suspicions that much of philosophy is ultimately a colossal waste of time. The criticism has taken many forms throughout history. The logical empiricists argued that metaphysical views are meaningless because they cannot be empirically verified. Not many people hold this view anymore, in part because it arguably doesn’t meet its own standards for meaningfulness, but in part too because of the extraordinary progress metaphysicians have made in last 100 years or so in gradually raising the standards of clarity and explicitness in the statement of their views, helping to put to bed at least some of the traditional accusations of incoherence.

Most metaphysicians...aren't really in the business of drawing a line-of-best-fit through their intuitions.

A more common complaint nowadays is that metaphysicians are overly reliant on ‘intuitions’, pre-theoretic hunches that are (the critics allege) products of evolution, culturally variable, and ultimately not reliable guides to what the world is like. Even worse, metaphysicians, insofar as they purport to be interested in the fundamental structure of reality, are in danger of trespassing on land rightfully claimed by physicists, only with tools far less suited to the task (armchair reflection is no match for the Large Hadron Collider).

It’s probably true that metaphysics could benefit from better understanding of science and scientific practice. But the misunderstanding goes both ways. Most metaphysicians (the good ones, at any rate!) aren’t really in the business of drawing a line-of-best-fit through their intuitions. Instead what you’ll typically find if you open up a metaphysics article is arguments of one kind or another. And the best arguments – the ones that get published and discussed – are often ones with counterintuitive conclusions, which reveal some previously unnoticed tension between our pre-theoretic commitments.

Here’s a classic example to illustrate what I mean. Imagine that, using a device he has invented, Professor Farnsworth scans his own brain and manipulates your brain to put it in exactly the state his brain was in when it was scanned, and vice versa. Question: is this a body transplant or a mind transplant? Do you wake up in Farnsworth’s old body after the operation, or do you wake up in your old body just with all of Farnsworth’s old memories, beliefs, hopes, character traits and so on? Most people think it’s the former – you go wherever your psychological states go.