This [opinion that the earth rests on water] is the most ancient explanation which has come down to us, and is attributed to Thales of Miletus.
Aristotle, De Caelo 294 a28-30).
He asserted water to be the principle of all things, and that the world had life, and was full of daemons: they say, too, that he was the original definer of the seasons of the year, and that it was he who divided the year into three hundred and sixty-five days.
He said that the reason of the Nile overflowing, was, that its streams were beaten back by the Etesian winds blowing in a contrary direction.
Diogenes Laertius, Thales of Miletus
Alexander also says, in his Successions of Philosophers, that he found the following dogmas also set down in the Commentaries of Pythagoras:
“That the monad was the beginning of everything. From the monad proceeds an indefinite duad, which is subordinate to the monad as to its cause. That from the monad and the indefinite duad proceed numbers. And from numbers signs. And from these last, lines of which plane figures consist. And from plane figures are derived solid bodies. And from solid bodies sensible bodies, of which last there are four elements; fire, water, earth, and air.”
He also taught that light and darkness, and cold and heat, and dryness and moisture, were equally divided in the world; and that, while heat was predominant it was summer; while cold had the mastery it was winter; when dryness prevailed it was spring; and when moisture preponderated, winter. And while all these qualities were on a level, then was the loveliest season of the year.
Diogenes Laertius, Pythagoras
Everything flows and nothing is left (unchanged).
Plato, Cratylus 402a
“This universe, which is the same for all, has not been made by any god or man, but it always has been, is, and will be an ever–living fire, kindling itself by regular measures and going out by regular measures”
“No man ever steps in the same river twice, for it is not the same river and he is not the same man.”
“Nature loves to hide.”
“Democritus says: By convention hot, by convention cold, but in reality atoms and void.”
Fr. 117, Diogenes Laertius IX, 72
“How could what is perish? How could it have come to be? For if it came into being, it is not; nor is it if ever it is going to be.”
“It is necessary to speak and to think what is; for being is, but nothing is not.”