Under and behind all outward appearances or manifestations, there must always be a substantial reality. This is Law.
Man considering the universe, of which he is a unit, sees nothing but change in matter, forces, and mental states. He sees nothing really is, but that everything is becoming or changing.
Nothing stands still, everything is being born, growing, or dying. The very instant a thing reaches its height, it begins to decline - nothing is permanent but change.
All things are evolving from other things and resolving into other things. A constant action and reaction - nothing endures but change - all of these changing things must be outward appearances or manifestations of underlying power.