The transcendental argument for the existence of God (TAG). Wikipedia defines the argument as follows:
- "The Transcendental Argument is an argument for the existence of God that attempts to show that logic, science, ethics (and generally every fact of human experience and knowledge) are not meaningful apart from a preconditioning belief in the existence of God."
That is, knowledge cannot be obtained absolutely unless the source of that knowledge is itself an absolute source (read: being/God). Therefore, either you subconsciously believe in an absolute being that upholds and makes absolute the laws of the universe/morality or you do not—and can not—know anything for certain.
- There are some objective logical absolutes.
- We can have concepts of these logical absolutes.
- These logical absolutes are not physical (you can't find them within the natural world).
- These logical absolutes are therefore conceptual.
- Concepts require a mind.
- Since the logical absolutes are true everywhere they must exist within an infinite mind.
- That mind is God.
- God exists.
Other iterations of the same general theme exist.
- Logic is rational, but atheism presupposes that everything comes from material sources.
- Logic isn't material, so atheism lacks any objective source for logic.
- Without an objective source for logic, atheism cannot employ logic.
- Therefore atheism is self refuting.
- Since atheism is refuted, theism must be true.
- God exists.
The standard requirement to the argument is that there are transcendental things such as science, logic, morality, and mathematics which are not physically in existence which are also part of reality (when you stop believing in them, they don't go away). Since these systems exist, *waves arms*, God exists.
The argument is popular within presuppositionalism and the associated apologetics. Presuppositionalism however tends to reverse the argument and simple begin at the conclusion. Logic depends on God, therefore you can't use logic to argue against God as that would be self-contradictory.
There are transcendental systems which exist and are neither conceptual nor physical. If this suggestion is possible then the argument crumbles due to a false dichotomy suggesting that all non-physical things are conceptual.
Others claim that TAG is a variation of the ontological argument, in that they both blur the line between concepts and reality. Imagining the most perfect being requires that that being exists (existing is more perfect than not exist) the line between conceptual and real is arbitrarily crossed.
"Where is the number 7?" - Those advocating the transcendental argument must contend that 7 exists within reality or within the mind of God. However in all cases 7 must have an actual location (since abstract transcendental mathematics is assumed to not exist). It doesn't go very far, but it is always amusing.
TANG or the Transcendental argument against the existence of God attempts to show that such logical absolutes cannot be absolutes if they are subjective by being God based. God could simply ignore the number 7 or believe that killing children is good and the logical absolutes would change. Therefore, they would not be logical absolutes or objectively true but rather subject to the whims of God.
So what? Many non-theists, when they are backed against the wall, will admit that they know nothing with 100% certainty. Humans generally will prefer some explanation rather than no explanation. However, providing "some explanation" does not make the claims in the explanation true. Absolute certainty is in general meaningless as by definition one would have to be omniscient to acquire it. Atheists do not in general make claims to the absolute truth of things; this is usually the domain of the theist.
An example of what some may call absolutely certain is the idea that the sun will rise tomorrow. To be truly absolute in certainty, you would require precognition; however, that is generally useless. It's much more accurate to state that based on the evidence of many days prior as well as our understanding of chemistry and the composition of stars that the sun will not soon cease to rise.