“Long ago this simple truth was clearly pointed out by Herbert Spencer, who arrived at it through a somewhat different process of reasoning.  It is borne out in everything we perceive—in the movement of a planet, in the surging and ebbing of the tide, in the reverberations of the air, the swinging of a pendulum, the oscillations of an electric current, and in the infinitely varied phenomena of organic life.  Does not the whole of human life attest to it?  Birth, growth, old age, and death of an individual, family, race, or nation, what is it all but a rhythm?  All life-manifestation, then, even in its most intricate form, as exemplified in man, however involved and inscrutable, is only a movement, to which the same general laws of movement which govern throughout the physical universe must be applicable.”

–Nikola Tesla

“The Problem of Increasing Human Energy (With Special References to the Harnessing of the Sun’s Energy.” Century Illustrated Magazine, June 1900.