A religious argument cannot be judged on whether it is logical. Rather, the question is what it inspired. Belief in a God that designed the universe is not necessarily the same thing Intelligent Design means today. The crucial question is whether his philosophy stayed within religion, or whether like today it tried to work its way into science. By the way, belief in a Creator does not in itself constitute Creationism. It depends on whether he was simply thinking outside of science or whether he was denying specific scientific claims. Please see http://www.religioustolerance.org for further information. (I have no involvement with the production of this site. I am merely someone who found it and posted a small message on the forum.)