  Schopenhauer held that the character of the will qua thing in itself—blind urge—expresses itself in the perpetual strivings of living creatures and in the forces of inorganic matter.  Grounding his proto-Darwinian philosophy of nature in his metaphysics and the empirical sciences of his day, Schopenhauer viewed nature as an arena where living beings compete to survive and procreate, where species adapt to environmental conditions, and, most emphasized by Schopenhauer, where sentient beings suffer  as virtual slaves to their will to life [Wille zum Leben]. 