If speculation tends thus to a terrific unity, in which all things are absorbed, action tends directly back to diversity. The first is the course or gravitation of mind; the second is the power of nature. Nature is manifold. The unity absorbs, and melts or reduces. Nature opens and creates. These two principles reappear and interpenetrate all things, all thought; the one, the many.
Representative Men: Seven Lectures (ed. 1850)