 Church brought both the general outlook and the specific distinctions of formal logic to bear on philosophy in a distinctive way by applying his “logistic method” to the philosophical topics he discussed. Conversely, he also wove certain aspects of his philosophy into the fabric of formal, mathematical logic as he presented it. The result was a formidable combination of philosophical vision and focused argumentation. For Church, the logistic method (or formalization) was not only necessary to obtain additional clarification beyond informal discussion and to make meta-mathematical investigations possible; it was also the ideal method for dealing with philosophical problems in epistemology, metaphysics and philosophy of language. It was Church’s view that one who does not aspire to this ideal falls short. However, he also recognized that formalization is not always appropriate. He did not demand that the natural sciences be formalized and even provided an informal philosophical discussion of semantics in the introductory chapter of his Introduction to Mathematical Logic (1956a). The theories and arguments discussed in this article describe and illustrate Church’s logistic method.