A Philosophical Argument for the Existence of the Soul

Richard Swinburne is an emeritus professor of philosophy at Oxford University and one the most prominent of contemporary philosophers. In his book, Are We Bodies Or Souls? he takes up Descartes' argument for the existence of the soul and amends it slightly to remove one of the classical objections philosophers have made to it.

The result is a succinct argument for the existence of the soul in human persons. His argument goes like this:

1. I am a substance which is thinking.
2. It is conceivable (i.e. logically possible) that while I am thinking my body is destroyed.
3. It is not conceivable (i.e. not logically possible) that 'I am thinking and yet I do not exist.'
4. I am therefore a substance which, it is conceivable, can continue to exist while my body is destroyed.
5. It is not conceivable (i.e. not logically possible) that a substance can lose all its parts simultaneously and yet continue to exist.
6. Therefore, I am a soul, a substance, whose only essential property is the capacity for thought.

A philosophical rule of thumb is that if a state of affairs contains a contradiction then it's said to be logically impossible. A square circle, for example, is inherently contradictory and cannot be imagined. It's therefore said to be logically impossible. If, however, a state of affairs contains no contradiction and can be imagined or conceived then it's said to be logically possible.* So, how does Swinburne's conclusion follow from the rest of his argument? According to 4. it's logically possible that I exist when my body ceases to exist, but according to 5. it's logically impossible that anything can continue to exist when every part of it is destroyed.

Therefore, there must be more to me than just my body. There must be something about me that can continue to exist even though every part of my body is destroyed.

That other part of me must be, from 1. and 2., that part of me which thinks, i.e. a soul (or mind), and which I identify as myself.

Swinburne gives a cogent defense of this argument in the book, which, though he claims it to be written for a broad audience, would be rather hard going for someone with little background in philosophy.

Nevertheless, in an age in which the reigning view on these matters is a philosophical materialism which denies the existence of a soul or mind, Swinburne's book is refreshing. * Not to go too far into the weeds on the notion of logical impossibility, there are two types of this. Strict logical impossibility occurs when a supposed state of affairs contains or entails a contradiction, e.g. a square triangle, a married bachelor, or living corpse. You cannot imagine or conceive of these. Broad logical impossibility, often called metaphysical impossibility, may not contain a contradiction and may be conceivable, but is nevertheless not capable of existing in the real world. Examples might include bringing about one's own existance, having color but not size, flying like Superman, or running a mile in zero seconds.