Already at an early stage in his life, when the Urfaust was being conceived, did Goethe sense the dynamic essence of the universe. He was deeply aware of the fact that the whole of existence, both in its physical and spiritual manifestations, is in a constant state of flux, with conflicting forces acting upon each other, eventually weaving themselves into a harmonious whole. This vast dynamic urge extends far beyond the biological into the very essence of the entire physical universe to the point where even matter itself is energy. His conviction became strengthened when he later took up the study of the natural sciences, and it played a most basic rôle in his view of life as an old man. Out of this idea of existence as ceaseless activity, which found varied poetic expression in his works, emerged a second concept equally important to an understanding of his philosophy: the concept of the polarity of conflicting antagonistic forces in nature, the name for which he took from the polarity of magnetism. Having accepted the fact that the nature of matter is force, he advanced to the idea that this force never expresses itself in a single phenomenon, but in two diagrammatically opposed entities or forces. Proceeding from the same point of departure they divide, repulse each other, finally to attract and unite again.