Abstract. This paper examines the impact of two formalizations of evolutionary biology on the antiselectionist critiques of the Intelligent Design (ID) movement. It looks first at attempts to apply the syntactic framework of the physical sciences to biology in the twentieth century, and to their effect upon the ID movement. It then examines the more heuristic account of biological-theory structure, namely, the semantic model. Finally, it concludes by advocating the semantic conception and emphasizing the problems that the semantic model creates for ID's negative and positive theses.