Science is often distinguished from other human enterprises by its progressive nature. Science, it is said, has "a progressive and public character"¹, and an essential feature of scientific knowledge is its "continued growth"². Just like Kant who complained that metaphysics has not yet found "the sure path of science"³, so many philosophers have thought that science can be effectively demarcated from religion, art, philosophy and politics by reference to its method; this method is thought to be sufficient to guarantee continuous progress for science or at least to give clear criteria for recognizing "progressive" developments within science.⁴