Thanks go to Matt Dillahunty of the Atheist Community of Austin for many of these observations.
Matt Slick is a christian apologist and founder of CARM(Christian Apologetics & Research Ministry). The Transcendental Argument for the Existence of God (or TAG for short) is Slick's attempt at proving god's existence through logic and philosophy.
You can read his full argument here:
To summarize:
Mr. Slick proposes that logical absolutes are conceptual.
Since they are Absolute they require an Absolute mind.
This Absolute mind is god.
TAG can easily get very messy. I've decided not to question any of the philosophy in TAG, even though in my experience many people do find it questionable. Going the philosophy route gets very messy very fast and I think simple analyses of his logic is enough to draw a meaningful conclusion.
I've found this is the simplest way of going about it:
One fatal problem arises when Mr. Slick fails to show that Logical Absolutes are conceptual.
Premise 6. A. states:
"Logic is a process of the mind. Logical absolutes provide the framework for logical thought processes. Therefore, Logical Absolutes are conceptual by nature."
"Logic is a process of the mind." I agree.
"Logical absolutes provide the framework for logical thought processes." I agree.
"Therefore, Logical Absolutes are conceptual by nature." Does not follow.
This is a logical fallacy on Mr. Slick's part.
Logical Absolutes <----- Logic
This simple diagram shows how logic is based on logical absolutes.
If logic is conceptual there is no requirement for logical absolutes to be conceptual. We create conceptions of non-conceptual things all the time.
Chair <----- Concept of Chair
Our concept of a chair is based on the chair.
Does this make the original physical chair necessarily conceptual? Of course not.
Mr. Slick continues with
Premise 6. B:
"Logical absolutes are either conceptual by nature or they are not."
I agree. They are either conceptual or non-conceptual.
B. i "If they are conceptual by nature then they are not dependent upon the physical universe for their existence."
I disagree. Mr. Slick has failed to show how concepts are not tied to the physical universe, he simply states it as true.
In reality concepts require a mind to conceive of them and everything we know of minds suggests they are physical (i.e. show me a mind without a brain). This is however irrelevant to the main point of showing that Logical Absolutes are conceptual. So I will move on.
B. ii "If they are non-conceptual by nature then
a. What is their nature?"
This is an odd way of suddenly trying to turn the burden of proof onto the reader. No one has claimed they are non-conceptual by nature.
In pointing out Mr. Slick's error in Premise 6. A. I am merely showing that his reasoning is flawed and thus he hasn't proven anything. I am not making a claim about the nature of logical absolutes myself. They still could be conceptual as far as I know. But it still needs to be proven.
b. "If it is denied that Logical Absolutes are either conceptual or physical, then there must be a 3rd (or 4th...) option. What would that option be?"
It is not denied that Logical Absolutes are either physical or conceptual. At this point their nature is simply unknown.
c. "If another option cannot be logically offered, then the only options available to us are conceptual and physical."
See response to d.
d. "Since logic is not a property of physical nature, see point 5 above, then we must conclude that they are conceptual by nature."
With c and d Mr. Slick continues his bizarre game of spinning the burden of proof. "Conceptual and Physical are the only options, can you think of any other ones? No? Then it must be true!" Meanwhile Mr. Slick has failed to actually prove that physical and conceptual ARE the only options. The burden is on HIM to prove this. He is the one presenting the argument and he must prove his own premises.
Mr. Slick is using physical vs conceptual as an absolute dichotomy here. While he has no justification to do this. "If something isn't physical it MUST be conceptual."
Firstly he has failed to prove these are the only two options.
Secondly the second option (conceptual) is possibly contingent on the first (physical). As I've already covered, concepts requires minds which require physical biology. If the conceptual depends on the physical they cannot be an absolute dichotomy.
Now we can argue about dualism back and forth. However the plain and simple philosophical controversy about it should shake anyone's faith in physical vs conceptual being a proven absolute dichotomy even if you ignore my first point.
We have to be very careful when dealing with absolute dichotomies. We don't know everything and these broad categorizations and generalizations are frequently and easily fallacious.
Most of the time they are structured in a more logically "strong" way.
For example:
Physical vs Non-Physical
or
Conceptual vs Non-Conceptual
rather than
Physical vs Conceptual
e. "Simply "denying" that Logical Absolutes are either conceptual or physical nature isn't sufficient."
It is not denied that Logical Absolutes could be either physical or conceptual. At this point their nature is simply unknown and the absolute dichotomy Mr. Slick draws his conclusion from has not been properly established.