For a long time, "philosophy of nature" (Naturphilosophie) was a derogatory term in the Marxist-Leninist vocabulary.¹ It applied to idealists like Schelling;² whereas Marxist-Leninists were said to do science. By "philosophy of nature" we do not mean simply a philosophic account of nature, which every theoretical system has to contain in one form or another. Aristotelianism has a philosophy of nature (basically inherited by the neo-Thomists, as we will see in Chapter 7) but Aristotelianism is not merely a philosophy of nature. One could call the pre-Socratics, including the Eleatics, philosophers of nature in the strict sense. However, the paradigm of Western philosophy of nature is in the work of John Scotus Eriugena, Paracelsus and the German mystics like Boehme, some Renaissance thinkers, Spinoza, and Schelling. As such, it has been a constitutive part of what we might call "the other way of doing philosophy" and has interacted not only with the mainstream of Western thinking, but also with what we called in Chapter 1 the "underground religiosity" that never quite surfaced in the form of an official theology.