Please permit me a few introductory personal remarks. Your expectations will be fulfilled. True to stereotype I shall of course talk about positivism. But let me reassure you immediately. Had it not been for the attractive title (which I owe to a suggestion by my friend Calvin Rollins), I might have chosen an alternative such as "The Pernicious Proclivities of Positivistic Perversion and Prohibitionism"! The power of positivistic thinking is, as I see it, severely limited: I shall be emphatic on the need for incisive revisions and ample liberalizations. As the older members of our association may well remember, I was an ardent propagandist for the outlook of logical positivism in the early thirties. Somewhat like Alfred Ayer in England, I was an enfant terrible (and consequently a bête noire) on the American philosophical scene. I had arrived, in the autumn of 1930, deeply imbued with the spirit of the Vienna Circle. Along with my father figures, Schlick, Carnap, and the early Wittgenstein, I had come to think of ours as a "philosophy to end all philosophies". In other words, I behaved myself like a philosophical prohibitionist. However, this iconoclastic phase soon gave way to a more moderate, widely appreciative, and constructive outlook. To my dismay I had come to realize that Occam's razor mobilizes the castration complex of the metaphysicians. Yet, having stereotyped myself (in the notorious fanfare article written in colloboration with A. E. Blumberg and published in the Journal of Philosophy in the spring of 1931), as a "logical positivist", the label has stuck to me ever since. As early as 1935, however, I abandoned the label (at least as far as I was concerned) and availed myself of the alias "logical empiricist".