"Die aristotelische "Physik' ist das verborgene Grundbuch der abendländischen Philosophie" (Heidegger). This sentence refers to a work and a time, in which physics was a philosophical discipline and nature an object of philosophy. Accordingly, the philosophers of Greek Antiquity were just as much concerned with metaphysics as with the study of nature. This was also true in the time of the presocratian: Thales, Heraklit, Anaximander, Demokrit, Leukipp or Empedokles; later Platon, Aristoteles, Theophrast and finally Epikur. This is even more true of the enduring influence of this epoch extending until the early modern time. The research of Galilei and Newton, as well as the natural philosophy of Leibniz or Descartes, still represent the indivisible unity of natural science and philosophy, which was broken only when the practical success of empirical science led to a stronger emancipation from the philosophy, and the latter, as a reaction, tried desperately to react to this with highly systematized and organized systems of metaphysics (including metaphysics of nature).