I was reflecting on the Interaction Problem today and had a few thoughts about it.  The problem is an objection against Cartesian Mind/Body Dualism, and goes roughly something like this: we can think of no possible mechanism for how an immaterial soul can interact with a material body.  If we can't come up with a mechanism, then it is likely that no such mechanism exists.  If no such mechanism exists, then an immaterial mind could not interact with a material body.  But the mind does interact with the body.  Therefore the mind must not be immaterial, and Cartesian Dualism is false.

Ignoring the potential issue with the Noseeum inference made in the argument (I don't see X, therefore X probably does not exist), another issue came to mind.  The whole argument revolves around the idea that it seems counter-intuitive that an immaterial substance (such as the Cartesian mind) could interact with a material substance (such as the body).  Perhaps even worse than counter-intuitive, it just seems strange. [1]

Let's also disregard the fact that counter-intuitiveness, and strangeness, are not good defeaters for an argument unrelated to those concepts (there are arguments from the Cartesian Dualist for why an immaterial soul must exist).  I still don't think the problem is as cutting as those who advance it would like to think.  Why? Well, when you think about it, it's really just as strange that material substances can interact with other material substances.  What is the mechanism for that type of interaction? Why think that such an interaction can take place?

But wait, you might say. We know that material substances interact with each other because we observe such interactions all the times in science (Or, you know, by just being aware of the world that we live in. But it's obviously more effective to shout "science" when objecting to something)!

Well, I might respond by saying that if Cartesian Dualism is true, then we regularly observe material and immaterial substances interacting together all the time, too.  Perhaps I'm just begging the question here, because we would have to assume that those type of interactions can take place in order to posit that Cartesian Dualism is true.  But if I am, then so are those who believe in material/material interactions.

This is because if we accept a broadly Humean metaphysics (a type of empiricism which most opponents of Cartesian Dualism seem to accept, implicitly or explicitly), then when we do science, we are not observing causal interactions at all.  Hume argued that we are really just observing the constant conjunction of events.  Humans have, Hume argued, a psychological tendency to infer from such constant conjunctions that a causal interaction has indeed taken place.  But let's be clear: if Hume is right, then we do not in fact observe the interaction of material substances.  Rather we infer such an interaction. So we have not directly observed such mechanisms for material/material interactions.  Given this lack of observation, these types of interactions appear just as strange as those being objected to!

Let's wind this up by summarizing what I am intending to show.  No, actually let's start by summarizing what I am not trying to show. I am not trying to show that Hume was right about causation, nor that Cartesian Dualism is true. I happen to dispute both of those theses personally (though I dispute the former much more strongly than the latter, and my view on the latter is closer to Cartesian Dualism than it is to modern Physicalism). What this post does show is that most people who put forth this objection prove too much and therefore have reason to discard it.

Objection

A possible objection to this post (brought to my attention by Steve) is that we do know the mechanisms for material/material interaction. These mechanisms are the fundamental forces, or the physical laws.  But I don't think this solves the problem. First, there is widespread disagreement over the actual nature of these concepts.  Are they prescriptive, or are they simply descriptive?  Do these laws or forces actually compel materials to interact with each other in certain ways (which seems, again, very strange), or are they simply names and descriptions we have given to certain behavior that we perceive. And that leads me to my second point: regardless of whether these fundamental laws or forces are descriptive or prescriptive, have we actually observed them? Or are we inferring them from the constant conjunction of events that we do observe? I submit that we have not observed them, and these concepts (though they sound more eloquent) fall to the same argument that Hume put forth from the start.

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Notes:
1.  The term I have most often seen in philosophical literature in this context is "queer."  Due to the charged nature with which this word has come to be perceived, I have chosen to use the word "strange" instead.

Some time ago I finished reading "Mind and Cosmos" by Thomas Nagel, philosopher at New York University.  I am not going to do a series on the book.  If you would like to check out a series on the book far superior to anything I could do (and from a much more scholastic perspective than our blog) check out Edward Feser's series here.

Thomas Nagel is one of the more influential philosophers right now. And though he is a committed atheist, he doesn't do a very good job of towing the line when it comes to secular orthodoxy that holds so much sway in universities today.

At any rate, I came across some vexing quotes I thought worth sharing.  Here is one that very much goes against the grain of scientific orthodoxy.

As I have said, doubts about the reductionist account of life go against the dominant scientific consensus, but that consensus faces problems of probability that I believe are not taken seriously enough, both with respect to the evolution of life forms through accidental mutation and natural selection and with respect to the formation from dead matter of physical systems capable of such evolution.  The more we learn about the intricacy of the genetic code and its control of the chemical processes of life, the harder those problems seem.[1]

Nagel certainly isn't the first to voice these ideas, but he is unique in that while serious Christian thinkers have voiced similar ideas, he is one of very few atheists who is willing to do so. One thing you shouldn't do, though, while reading quotes of his like this is to think that he is edging towards some sort of deism of theism. Rather, he merely suggests that the materialist reductionist oligarchy today is off-base. His contention is that non-material things also exist, and that there is some non-material explanation at the root of many of our vexing questions. He sketches some ideas in the book, but you'll have to read it to learn more. Another quote:

If we continue to assume that we are parts of the physical world and that the evolutionary process that brought us into existence is part of its history, then something must be added to the physical conception of the natural order that allows us to explain how it can give rise to organisms that are more than physical.  The resources of physical science are not adequate for this purpose, because those resources were developed to account for data of a completely different kind.[2]

He really drives the point home here:

The existence of consciousness is both one of the most familiar and one of the most astounding things about the world.  No conception of the natural order that does not reveal it as something to be expected can aspire even to the outline of completeness.  And if physical science, whatever it may have to say about the origin of life, leaves us necessarily in the dark about consciousness, that shows that it cannot provide the basic form of intelligibility for this world.  There must be a very different way in which things as they are make sense, and that includes the way the physical world is, since the problem cannot be quarantined in the mind.[3]

In noting the difference between basic "animal" consciousness and reason, he states:

Reason can take us beyond the appearances because it has completely general validity, rather than merely local utility.  If we have it, we recognize that it can be neither confirmed nor undermined by a theory of its evolutionary origins, nor by any other external view of itself.  We cannot distance ourselves from it.  That was Descartes' insight.[4]

And finally, in criticizing the Anthropic Principle as an explanation for our existence, Nagel makes this beautiful remark.  I actually laughed out loud when I read it.

If I ask for an explanation of the fact that the air pressure in the transcontinental jet is close to that at sea level, it is no answer to point out that if it weren't, I'd be dead.[5]

Notes:
1.  Nagel, Mind and Cosmos, p. 9
2.  Ibid., p. 46
3.  Ibid., p. 53
4.  Ibid., p. 82
5.  Ibid., p. 95