Nature is the mother, father, and child of us all. The whole of forces at world on the earth. The system of life as set forth by God and largely left unmanipulated by man. Nature is whatever you need it to be right now. Man is a participant in Nature, and a very special one, for he is capable of recognizing and comprehending Nature from an objective viewpoint.
Nature is everything.
Or, from Man's foolish perspective, it is everything that is not Man. Either way, Nature Is. I never thought about it until the course description, but the idea of the course as being interdisciplinary struck me. Nature does include science, philosophy and art. Nature is the life we as humans attempt to understand.