Modern Physiology and the Soul

I spent a portion of my weekend, a few weekends ago, at a conference on philosophy, and there were more than a few presenters on Plato.

Now, I have a lot of problems with the old Greeks (even Epicurus, who’s by far my favorite), but one of the things that came up in a few of the presentations, two of which were specifically on the topic, was the three part soul, according to Plato, and this is a major sticking point for me.

For those who haven’t read book four of the Republic, the statement of the soul is pretty simple. This soul consists of three parts:

Logos – The rational mind
Thymos – The emotion, spiritedness (generally considered masculine)
Eros – The appetite, desire (generally considered feminine)

Now, of course, all of this makes sense in the context of Plato, who noticed that there are three distinct functions in the individual. That we have the capacity for logic, we have a certain degree of desire and that we sometimes see the need to fight, to stand up for something. These are the three functions that he is trying to showcase.

I have no problem with Plato for presenting these three functions. My problem is with the attribution of these functions to the soul.

I am, by no means, an expert in physiology, but it seems to me that these three functions can be explained physiologically.

We know that the temporal lobe controls our capacity for foresight and reason. We know that the adrenal glands fuel the fight or flight reaction. We know that the limbic system controls most of our visceral emotional reactions, including many of our desires (that which do not come from other physiological components, like the physical hunger felt in a starved stomach).

With this new data present, doesn’t this undermine Plato’s version of the soul?

When I presented this to the young man on stage he responded by saying that it does, which I’m glad he did (because it was very intellectually honest of him, in my opinion). He then went on to explain that in the context of Plato’s time, Plato’s soul is a very powerful device. That’s fair, but it doesn’t explain why were should continue discussing his version of the soul in a time when we know it does not exist.

After posing the question, I had a few issues and a few ideas.

The first is something I’ve known for a while, but thought was worth bringing up, as the debate over the existence of a soul hinges on this:

The existence of something can be verified through its function. Which is to say, if something performs a function, then we can be sure that it exists.

I am fairly comfortable with that criteria for existence. It’s a criteria I have used for some time, and while it generally takes some explanation for people who don’t understand that being the object of a verb (like, say, if something is seen) is performing a function, it’s a solid qualifier once we get around that point.

That said, what is the function of a soul?

We’ve removed Plato’s functions, as they are performed by something else entirely.

The function of creation is not entirely understood, but it largely assumed to be the product of the physical brain and interactions within various structures (Dr. V.S. Ramachandran has some very interesting statements about the root of creativity based on interactions within the brain).

The function of consciousness is no longer explained through the use of the soul (which was the placeholder for some time). The top students of consciousness now recognize it as the product of neurology within the brain.

The capacity for morality can be largely attributed to the consideration of consequences, which is a function performed by the temporal lobe, which gives us that ability to make predictions.

So, what is the function of the soul? What function does it still act as a placeholder for, that we do not already have at least a rudimentary understanding of?

In the age of science, is this conceptualization of a part of ourselves that is inexplicable really necessary? Is it true?

I concede that I lean towards denying the existence of a soul categorically, as I cannot find a function, but it is an open question and, if such a function can be demonstrated, I would be very happy to see it.