It is sometimes mistakenly suggested that scientists deny the existence of such phenomena because they violate currently accepted theories of nature. From our discussion of the scientific process in Chapters 1 and 2, it should be clear that this claim is false. All scientists are in the business of overturning currently accepted theories of nature, for it is only by changing and refining our current views, while maintaining, of course, the connectivity principle, that we can hope to get nearer the truth. When a new phenomenon contradicts currently accepted knowledge, scientists question it and seek alternative explanations for it. But this is not the reason that psychologists do not believe in the existence of ESP. The reason is simpler. There is just no scientific evidence for it. In short, there is no demonstrated phenomenon that needs scientific explanation (Alcock, 1981, 1984, 1990; Hines, 1988; Humphrey, 1996; Hyman, 1992, 1996; Milton & Wiseman, 1999).