Schopenhauer uses what he calls empirical metaphysics, to give an explanation of the essence of the world, and of living things. In doing so, he always tries to make interpretations which are grounded in the sciences. But since all sciences use the principle of sufficient reason, and restrict their observations to the phenomenal world, they can never get to what things are in themselves. There would be no way to do so, if Schopenhauer were not, as a philosopher, himself both a knower and a physically embodied person in the world. Introspection shows the will to live as causality seen from inside. From there, he moves by analogy to other living beings, and even to the whole of nature. His precursors in philosophy and science, up to and including his time, are outlined, and also compared to later views, up to the present.

Ortrun Schulz (* 27. Februar 1960 in Hannover) ist eine deutsche Philosophin und freie Schriftstellerin. Von 1992 bis 1994 war sie Vorstandsmitglied der Schopenhauer-Gesellschaft und von 1992 bis 2005 Redakteurin des Schopenhauer-Jahrbuchs. Seit 2005 bietet sie philosophische Lebensberatung an. Seit Juni 1998 ist sie in Zusammenarbeit mit Yasuo Kamata (Kwansei Gakuin Universität, Japan) Kontaktperson der „International Schopenhauer Mailing List“.