πᾶν μὲν τὸ δυσέφικτον παρὰ τοῖς πολλοῖς εὐδιάβλητον ἔχει φύσιν - Ptolemy

I know that I am mortal by nature and ephemeral, but when I trace at my pleasure the windings to and fro of the heavenly bodies, I no longer touch earth with my feet. I stand in the presence of Zeus himself and take my fill of ambrosia.

There are three classes of friendship and enmity, since men are so disposed to one another either by preference or by need or through pleasure and pain.

We consider it a good principle to explain the phenomena by the simplest hypothesis possible.