I will begin by telling some of the history of the book and of its misleading title. In i9601 was invited to open a discussion on “The Logic of the Social Sciences” at a congress of German sociologists in Tubingen. I accepted, and I heard that my opening address would be followed by a reply from Professor Theodor W. Adorno of Frankfurt. It was suggested to me by the organizers that, in order to make a fruitful discussion possible, I should formulate my views in a number of definite theses. This I did: my opening address to that discussion, delivered in 1961, consisted of twenty-seven sharply formulated theses, plus a programmatic formulation of the task of the theoretical social sciences. Of course, I formulated these theses so as to make it difficult for any Hegelian and Marxist (such as Adorno) to accept them; and I supported them as well as I could by arguments. Owing to the limited time available, I confined myself to fundamentals, and I tried to avoid repeating what I had said elsewhere.