The TAG is a transcendental argument that attempts to prove that God is the precondition for logic, reason, or morality. The argument proceeds as follows:[4]
- God is a necessary precondition for logic and morality (because these are immaterial, yet real universals).
- People depend upon logic and morality, showing that they depend upon the universal, immaterial, and abstract realities which could not exist in a materialist universe but presupposes (presumes) the existence of an immaterial and absolute God.
- Therefore, God exists. If He didn’t, we could not rely upon logic, reason, morality, and other absolute universals (which are required and assumed to live in this universe, let alone to debate), and could not exist in a materialist universe where there are no absolute standards or an absolute Lawgiver.
Cornelius Van Til likewise wrote:
We must point out … that univocal reasoning itself leads to self-contradiction, not only from a theistic point of view, but from a non-theistic point of view as well… It is this that we ought to mean when we say that we reason from the impossibility of the contrary. The contrary is impossible only if it is self-contradictory when operating on the basis of its own assumptions.— (A Survey of Christian Epistemology [Philadelphia: Presbyterian and Reformed, 1969], p. 204).