Topics Mind

Question Human beings have a certain self awareness that nobody seems to fully comprehend. Is it possible that plants and animals have this same cognition but are simply limited in their ability to communicate with the physical world? It seems scientifically unlikely but science is built on physical evidence, and thoughts are not physical. They’re metaphysical. So, we can’t really comprehend their nature, right? Are there some theologians and philosophers who’ve theorized that plants and animals have thoughts just like people?

Accepted:
April 1, 2009

Comments

Two comments on the central pair of assertions: "[T]houghts are not physical. They're metaphysical" -- one terminological (but not insignificant), the other more substantial.

(1) The terminological comment is this: "Metaphysical" does not mean "non-physical", "supernatural", or anything of that kind. Metaphysics is just the traditional label for a bunch of topics famously discussed -- though not for the first time! -- in Aristotle's Metaphysics.

That book, or rather collection of books, is so called because it was placed meta ta phusika, after the Physics, by ancient editors. Its topics include questions like what makes something an object rather than an event or process? must objects have essential properties and if so what? are numbers a kind of object? what is a cause? Now, those questions (and similar ones that we also nowadays by extension call metaphysical) raise very general issues. And you can see why the ancients might have been at a bit of a loss as to how to classify them, and so just called them -- in effect -- "the sort of questions that were dealt with by Aristotle after some more tractable questions of physics". But do note that they are mostly very general questions about the same world that e.g. science and mathematics addresses: they are not essentially questions about some further, supernatural or non-natural, realm. Indeed, lots of contemporary metaphysicians -- i.e. lots of theorists interested in such very general questions -- are naturalists, and suppose that the natural world that science and mathematics addresses is the only world there is. For more, see this Stanford Encyclopedia article.

(2) Leaving that aside, though: why should we suppose that thoughts are not physical? What does that mean? Is it true? After all, thoughts are states or events that dispose us to suitable actions: and we've every reason to suppose that our actions are non-spookily generated by neural events. So maybe talking about thoughts etc. is just another way of talking about those physical happenings (as it were, a software rather than a hardware level of description of the distributed processing system in our skulls).

And certainly, it isn't obvious that "thoughts are not physical", as the arguments in any introductory book in the philosophy of mind should make clear. (I still quite like this student-friendly book!)

I would like to focus on your last question: Is it possible that plants and animals have thoughts just like people? Let's take animals first. We are animals, so at least some animals have thoughts just like people. Our nearest animal relatives--the primates--probably have thoughts very much like ours, though (perhaps with a few very special exceptions) theirs differ from ours in that none of theirs are expressed in language (while some, if not all, of ours probably are). (The few very special exceptions would be those primates who have been taught various kinds of sign languages or artificial languages.) Going down the evolutionary tree, I'd be willing to say that other mammals have thoughts not unlike ours, etc. In fact, I'd be willing to say that any animal that has a suitably rich nervous system might have thoughts not unlike ours (what counts as "suitably rich" is open for debate, of course). In fact, I'll propose that having a nervous system (either biological or artificial) is a necessary condition for having thoughts.

That probably rules out plants.