Abstract
The approach taken in this introductory exposition of the philosophy of Whitehead’s later period is based upon the view that both the basic questions and the procedure of his earlier investigations in the philosophy of science had changed. Whereas before he had been concerned with problems lying essentially within the domain of theoretical physics, Whitehead came to see that an adequate response to his questions about the post-Newtonian concept of nature leads to the still more general kind of question that has been the subject of systematic philosophy since the time of the Greeks. In order to secure a thoroughly consistent and complete explanation of the concepts treated in empirical science, Whitehead turned to the more fundamental approach of metaphysical philosophy, which proceeds according to certain very general criteria in search of a systematic account of the ultimate, non-derivative, or complete fact.