"...Intellectually, the dominating figure...was Ernst Mach, the physicist. That was the principle of thinking in which we all grew up, and at first all adopted it. But some of us—My psychological thinking begins directly with Ernst Mach. Mach in his famous book The Analysis of Sensations explains or assumes that while all our individual sensations have an original pure quality, they are constantly modified by experience. There is only an original order and then the experiential change. Which led me to the conclusion that if you can show that experience can change the thing, why need there be an original quality? The original quality may have arisen in the same fashion. So it was only a step beyond Mach, which turns against him with the result that my own psychology developed. In this sense I began from the same thing on which the logical positivist [movement]—Schlick, Neurath, Carnap, and so on—developed from Vienna; but split at the base, led us apart very much. But these two apparently absolutely contrary trends come from a common initial viewpoint."