The invalidity of an argument that stems from scientific materialism

Neurological research ha been done in which people's brains are observed while they undergo changes in their subjective internal states. By this I mean that they are told to try to bring about certain thoughts, ideas, emotions, intentions &c. The researchers can then correlate these internal states with the brain states that they observe. This tells them more about the structure of the brain and its relationship to our thoughts, emotions &c. Certainly a noble and interesting area of research, one that might be useful in the diagnosing and treating of certain physical and chemical disorders that might lead to mental and emotional problems.

But scientific materialist do more than recognize the measurable correlation between these subjective internal states and their correlating brain states. They argue that the cause of these subjective internal states are the correlating brain states. The argument goes as follows:

If a person is subject to some internal state, then their brain has a brain state that corresponds to that internal state.

A person's brain has a brain state that corresponds to some internal state.

Therefore the person is subject to that internal state.

This is an invalid argument. While the conditional statement is simply a restatement of the research data, the rest of the argument is an example of the fallacy of affirming the consequent.

It may be true that particular brain states are necessary for certain subjective internal states. But this is certainly not a problem for an Aristotelian or a Thomist, whose philosophical psychology and philosophical anthropology requires the activity of the internal senses for any kind of thought: "The Philosopher says (Metaph. i, 1; Poster. ii, 15) that the principle of knowledge is in the senses" (Summa Theologiae I, q. 84, a. 6 sed contra). It does not follow from the research, however, that particular brains states are a sufficient reason for certain subjective internal states. If scientific materialists are correct, at least insofar as human nature is concerned, they will have to do more than point to these kinds of studies to prove it.

Proof for the immortality of the human soul

The following proof has been derived using St. Thomas Aquinas' Summa Theologiae, I, 75.

Every intellect is that which can know all corporeal things.
Every human soul is an intellect.
Therefore, every human soul is that which can know all corporeal things.

Nothing that can know all corporeal things is corporeal.
Every human soul is that which can know all corporeal things.
Therefore, no human soul is corporeal.
Which is to say that every human soul is non-corporeal.

Every non-corporeal thing is that which has an operation that body does not share.
Every human soul is non-corporeal.
Therefore, every human soul is that which has an operation body does not share.

Everything that has an operation body does not share is that which has an operation in itself.
Every human soul is that which has an operation body does not share.
Therefore, every human soul is that which has an operation in itself.

Everything that has an operation in itself is that which subsists in itself.
Every human soul is that which has an operation in itself.
Therefore, every human soul is that which subsists in itself.

Everything that subsists in itself is a substance.
Every human soul is that which subsists in itself.
Therefore, every human soul is a substance.

No substance is corruptible per accidens.
Every human soul is a substance.
Therefore, no human soul is corruptible per accidens.

Every form is an act.
Every human soul is a form.
Therefore, every human soul is an act.

Every act is that which exists by virtue of itself.
Every human soul is an act.
Therefore, every human soul is that which exists by virtue of itself.

Nothing that exists by virtue of itself is corruptible per se.
Every human soul is that which exists by virtue of itself.
Therefore, no human soul is corruptible per se.

If the human soul is corruptible, then the human soul is corruptible per se or the human soul is corruptible per accidens.
No human soul is corruptible per se and no human soul is corruptible per accidens.
Therefore, no human soul is corruptible.
Which is to say that the human soul is incorruptible

That which is incorruptible is immortal.
The human soul is incorruptible.
Therefore, the human soul is immortal.

Error has no rights

Every evil is a privation.
Every error is an evil (of the intellect).
Therefore, every error is a privation.


Every privation is a lack of being (in a being that should have what it lacks).
Every error is a privation.
Therefore, every error is a lack of being.


No lack of being has rights (because nothing can be truly predicated of that which does not exist).
Every error is a lack of being.
Therefore, no error has rights.

My problem with the so-called "existential fallacy"

If we're not actually talking about things, then it's not philosophy, it's just word games.

If something doesn't exist, then nothing can be truly predicated of it. The problem with the following syllogism:

All rational beings are persons.
All Martians are rational.
Therefore, some Martians are persons.

is not that I have assumed existential import, thus committing a formal fallacy. The problem is that the minor premise is false. It is false because Martians do not exist.* Therefore, nothing can truly be predicated of them.

It is not a good idea to mathematize and abstract logic to the point where we forget the primacy of being

*If we ever discover that there are Martians, I will obviously have to change my example.

A valid argument

1. If you do not have faith, you will not be saved (Eph 2.8)

2. If you do not do works, you do not have faith (Jas 2.17)

3. If you do not do works, you will not be saved (2,1 HS)