One of the problems I have with Intelligent Design Creationists (IDCs) is that if one follows what they say, the universe and what happens within would be incomprehensible. Their argument is that of the God of the gaps. When they show that we do not know how things work, they can offer God as the answer. This, to some extent, would be reasonable, but only if that God they offered was reasonable. He is not.
They must first work against the laws of science, because they lead to a belief in evolution. We are constantly discovering more and more about the world which validates evolution and evolutionary understanding of the age of the universe. This, however, is something many, if not most IDCs are actively rejecting. Indeed, they see themselves as offering an alternative to evolution. Scientifically, they offer nothing — just philosophical questions. They cannot offer data. They cannot offer predictions of what one would expect in a universe created by a creator to use as a way to test their idea. There is no scientific hypothesis being offered. All they can suggest for us is an incomprehensible universe which was put together by an irrational God — their God made a universe whose appearance runs contrary to what they suggest to be fact. God, they argue, can do anything he would like, even making thing appear contrary to what they actually are, and there is nothing wrong with this; his omnipotence and will are explanation enough. This response and line of thought demonstrates their nominalism.
The nominalist God is arbitrary; analogy would have no ability in being used to determine anything about him, because the only thing which is true about God is his will, a will which he is free to change even if it were to contradict his own previous decisions. Michael Allen Gillespie describes this quite well in the thought of Ockham, whose work many consider as the nominalist foundation:
Even though evolution appears to meet the laws of nature as they exist today, IDCs claim this would not be sufficient evidence for evolution, because they cannot accept the assumption that the laws of nature are constant. The universe is arbitrary, how it runs is arbitrary, and if there is anything which is keeping things going, and any current laws of nature to be found, it is because God wills it to be this for now. Such a response, of course, runs contrary to Catholic understanding of God, because we believe him not only to be omnipotent, but rational as well.
 Michael Allen Gillespie, The Theological Origins of Modernity (Chicago: The University of Chicago Press, 2008), 23.