New 5-minute Philosopher video: What about metaphysics?

Simplicio: Hello, Hypatia. I would like to talk to you about something we left unexamined last time

Hypatia: Hi Simplicio. You mean when we were talking about how philosophy makes progress?

S: Exactly. You said that perhaps even metaphysics makes progress. But you did not sound very sure.

H: Yes, you picked up on something interesting there, Simplicio. You know, I think metaphysics is a difficult field of philosophy, and even philosophers themselves have strong opinions about its worth.

S: But isn't metaphysics one of the classic areas of inquiry in philosophy? Perhaps one of the most fundamental, from which much else philosophy stems?

H: Yes, historically that is certainly the case. The word itself comes from the fact that Aristotle wrote the books on what today we call metaphysics after he wrote those on physics. And as you know, "meta" simply means beyond. This is somewhat appropriate, because much of the discussion in modern times hinges on what exactly science has to say about metaphysics, and if the latter can be reduced to physics.

S: Okay, but before we get into that, can you remind me of some of the typical issues studied by metaphysicians?

H: Well, metaphysicians are concerned of course with the existence of god, and indeed with the very concept of existence. They are also interested in the difference between universals and particulars, in the idea of causation, and in the concept of time. They discuss free will, personal identity, and the difference between realism and anti-realism.

S: Wow, that is quite a lot. I seriously doubt we will be able into all of that today

H: Indeed, but perhaps we can pick on a few examples that show how metaphysics has interesting things to say, and where it can't do without a strong input from science.

S: Yes, that sounds like a reasonable approach. What do you think is the question in metaphysics where scientists have the most to contribute?

H: That would be the concept of time. It seems that these days one simply cannot seriously talk about time without getting into deep discussions of general relativity and perhaps even of quantum mechanics. Clearly, that is an area where physicists have a lot to say.

S: True, but don't you think that philosophers can also contribute? For instance, we can ask whether time travel is physically possible, which is again a question for physicists. But we can also investigate the logical puzzles that arise from time traveling, and perhaps even think about the coherence of the very idea of traveling in time.

H: That's right, Simplicio. For example, philosopher David Lewis published some interesting discussions about backward causation and causal loops.

S: Ah, yes, I remember! Backward causation happens for instance if I should punch a time traveler before he gets into his time machine and goes backward in time. The bruise from my punch would form before I actually punched him!

H: Yes, while an example of causal loop would be a situation where someone goes back in time to tell his younger self how to build a time machine, so that he can go back in time to tell his younger self how to build a time machine, and so on.

S: Wow, my head spins!

H: Exactly. Anyway, these are interesting discussions about the logic of time travel, and physicists and philosophers can get together for a better understanding of the underlying concept of time itself.

S: Okay, what about an example of metaphysics where science has relatively little to say?

H: Well, there are several, actually. My favorite candidates are the concept of causation, that of free will, and that of personal identity. Causation, for instance, is something that science takes for granted, but philosophers have come up with different theories of what it means.

S: Right, beginning with David Hume's analysis, we have the regularity theory as well as the counterfactual theory. My understanding is that these are accounts of causation, not theories in the scientific sense, right?

H: Yes, they are meant to investigate what we mean and how we think when we talk about causality. The same goes for theories of personal identity or free will.

S: This is interesting, because it gets to the root of the difference in the use of theory in science and philosophy, right?

H: Good point, Simplicio. In science a theory is an empirically verifiable set of statements about how the world works. In philosophy perhaps we should use the word "account" instead, to indicate that we are interested in how to think about certain concepts, as well as in the implications of certain ways of thinking about those concepts.

S: Well, it would be interesting to hang around and discuss free will or personal identity, but it's getting late. Until next time, Hypatia.

H: Always glad to see you, Simplicio.