The Monad represents the essence of God, the Dyad, his generative and reproductive faculty. The latter brings the world into being, the visible unfolding of God in time and space. Now the real world is triple. For just as man is composed of three elements, which are distinct though blended in one another, body, soul, and spirit; so the universe is divided into three concentric spheres: the natural, the human, and the divine world. The _Triad_ or _ternary law_ is accordingly the constitutive life of things and the real key to life. It is met with at every step on the ladder of life, from the constitution of the organic cell through the physiological constitution of the animal body, the working of the blood and the cerebro-spinal systems, right on to the super-physical constitution of man, to that of the universe and of God. Thus, as by enchantment, it opens up to the amazed spirit the inner structure of the universe, shows the infinite correspondences of the microcosm and the macrocosm. It acts like a light, passing into things to make them transparent, lighting up small and great worlds like so many magic lanterns. Let us explain this law by the essential correspondence of man with the universe. Pythagoras affirmed that the mind of man, or the intellect, takes from God its immortal and invisible, its absolutely active, nature. For the mind is that which moves itself. He defined the body as being its mortal, divisible, and passive part, and thought that what we call _soul_ is closely united to the mind, though formed of a third intermediate element, coming from the _cosmic fluid_. The soul, therefore, resembles an ethereal body which the spirit weaves and builds for itself. Without this ethereal body, the material body could not be purified, it would be only an inert and lifeless mass.[13] The soul possesses a form like that of the body it vivifies, and which it survives after dissolution or death. Then, as Pythagoras expresses it, in terms repeated by Plato, the _subtile chariot_ either carries off the spirit to divine spheres or allows it to fall back into the dusky regions of matter, according as it is more or less good or bad. The constitution and evolution of man is repeated in ever-increasing circles over the whole scale of beings and in every sphere. Just as the human Psyche struggles between the spirit which attracts and the body which holds it back, so also humanity evolves between the natural and animal world into which it plunges by reason of its earthly roots, and the divine world of pure spirits, its heavenly source, towards which it aspires to rise. And what happens in humanity happens in all lands and solar systems in ever differing proportions, ever new modes. Extend the circle to infinity, and, if you can, form one single concept of the limitless worlds. What will you find there? The creative thought, the astral fluid, and worlds in evolution: the spirit, soul, and body of divinity.