ABSTRACT
§ 1 . From one point of view all sciences are one science, the science of one universe. But from another point of view the sciences are manifold. Between the two hypothetical points, that of a world of objects regarded as containing implicitly a unity and intelligibility of its own and that of the same world transformed by the activity of thought into a system of knowledge, there lies all the process of reconstruction whose recorded steps make up the history of human thought. So long as that reconstruction remains incomplete, the sciences can only be called one science hypothetically and in terms of faith rather than knowledge. For practical purposes the sciences tend to become more distinct rather than more united as knowledge progresses. As each province of inquiry advances in accuracy it demands from the student more specialisation and greater elaboration of detail. The result is what we have called progressive differentiation, which implies increasing discrimination of all that is at first vaguely and crudely conceived as forming the content of any particular science.
