Michael Martin once wrote an article in which he tried to use the presuppositionalist position to disprove the existence of God (he called his position TANG). Unfortunately, many atheists still think he actually succeeded. Thus, I shall offer a response here.
The first problem with Martin’s position (TANG) against the Transcendental Argument for the Existence of God (TAG) is found in the following:
If TANG is a sound argument, then obviously TAG is not, for it is logically impossible that there be two sound arguments with contradictory conclusions. On the other hand, if TANG is unsound, it does not follow that TAG is sound.
What Martin forgets is that it is also true that if TAG is a sound argument, then obviously TANG is not. But Martin doesn’t even want to begin to think about that possiblity. Instead, he focuses only on debunking TAG.
Martin begins with logic:
Logic presupposes that its principles are necessarily true. However, according to the brand of Christianity assumed by TAG, God created everything, including logic; or at least everything, including logic, is dependent on God.
First, God creating everything would not include logic, as logic is not a thing. But secondly (and more importantly), is the idea of what kind of dependence. If we say that logic is dependent on God, what is meant by that?
Martin thinks:
But if something is created by or is dependent on God, it is not necessary–it is contingent on God. And if principles of logic are contingent on God, they are not logically necessary.
Martin, therefore, seeks to link dependency with contingency. But this is to ignore the fact that there are certain things that are necessarily contingent. The Christian states that logic is dependent upon God insofar as logic is an attribute of God. That is, it is part of the ontology of God. If God exists, logic necessarily exists because God is logical. Logic is one of His attributes. If He exists, logic does too.
Therefore, Martin’s conclusion is erroneous when he says:
Moreover, if principles of logic are contingent on God, God could change them.
God could no more change the principles of logic than He could change the fact that He exists and make Himself non-existent. This does not in any way make logic “higher” than God, it merely points out that God’s existence is all that is required for logic to be valid, and that the instant God exists and does not non-exist, the principles of logic are affirmed. So long as God’s existence never ceases, logic never ceases.
Thus, God could make the law of noncontradiction false; in other words, God could arrange matters so that a proposition and its negation were true at the same time.
Again, this does not follow, for the laws of logic are not something God wills into being–they are something that He is. As soon as God is A and not non-A then we have logic. Logic, therefore, is contingent upon God’s existence only and not upon God’s willing anything. Thus, God cannot will a contradiction unless He could be a contradiction.
So, one must conclude that logic is not dependent on God, and, insofar as the Christian world view assumes that logic so dependent, it is false.
But this is, of course, a strawman, for the manner in which the Christian world view assumes logic is dependent upon God is that it is dependent upon His existence and His attributes, not upon His will. Logic is dependent upon God because if God did not exist, logic would not exist either (God is the source of all existence–no existence exists that is not God or created by God).
Martin then moves on to the subject of science:
[Science] presupposes the uniformity of nature: that natural laws govern the world and that there are no violations of such laws. However, Christianity presupposes that there are miracles in which natural laws are violated. Since to make sense of science one must assume that there are no miracles, one must further assume that Christianity is false.
Science is not the determiner of “true” or “false” and thus cannot make any statement as to whether Christianity is true or false. Science is a method of investigation, not an epistemological philosophy. People who assume a naturalistic science will be like Martin above, but it is not science that holds friction with Christianity, it is Martin’s naturalism. Christians can also use the scientific method and come to conclusions about the nature of reality. These conclusions do not rule out the supernatural by fide, and thus “miracles” are not a violation of science (although they are a violation of naturalism–but when would any Christian care about that?).
Martin then ends with morality:
The type of Christian morality assumed by TAG is some version of the Divine Command Theory, the view that moral obligation is dependent on the will of God. But such a view is incompatible with objective morality. On the one hand, on this view what is moral is a function of the arbitrary will of God; for instance, if God wills that cruelty for its own sake is good, then it is. On the other hand, determining the will of God is impossible since there are different alleged sources of this will (The Bible, the Koran, The Book of Mormon, etc) and different interpretations of what these sources say; moreover; there is no rational way to reconcile these differences. Thus, the existence of an objective morality presupposes the falsehood of the Christian world view assumed by TAG.
Here we see a bunch of non sequitur. First, if something is objectively true it does not matter whether a subject knows it or not. Thus, Martin’s claim that “determining the will of God is impossible” is irrelevant. If morality is based on the will of God, then it is based on the will of God and our knowledge of it has nothing to do with its objectivity. God could easily give us a moral code that we must live by or He will punish us for it despite the fact that we don’t know it and that would not alter the fact that we live under that moral law.
Martin is instead arguing that it is impossible to know what objective morality is, which is quite another thing from arguing that there is no objective morality. The Christian will respond by saying that there is a way to know what God’s morality is–belief in the Bible. The atheist may disagree, but his disagreement is one of epistemological evidence and not one on whether God’s law is objective or not.
As you can see, Martin’s critique of TAG leaves much to be desired. His TANG position does not follow. And while it is true that that does not prove TAG correct, it does mean that TAG is still plausible.