Twofold is what I shall say: for at one time they [i.e., the elements] grew to be only one out of many, at another time again they separate to be many out of one.
And double is the birth of mortal things, double their death.
For the one [i.e., birth] is both born and destroyed by the coming together of all things, while the other inversely, when they are separated, is nourished and flies apart?
And these [elements] incessantly exchange their places continually, sometimes by Love all coming together into one, sometimes again each one carried off by the hatred of Strife.
Thus, insofar as they have learned to grow as one out of many, and inversely, the one separating again, they end up being many, to that extent they become, and they do not have a steadfast lifetime; but insofar as they incessantly exchange their places continually, to that extent they always are, immobile in a circle.
~ Empedocles 444 B.C.