He became a creationist around 1976, and gave testimony defending creation science at the "McLean v. Arkansas" and "Edwards v. Aguillard" court cases. During the latter case, he co-authored the creation science supplementary textbook "Of Pandas and People". The case decision went against teaching creation science in public schools, and the authors then altered all references to creationism to refer to intelligent design before the book was published in 1989. He subsequently became a Fellow of the Discovery Institute, and continued to endorse young Earth creationism.