Here’s a typical passage from the ancient Greek philosopher Parmenides.
“The thing that can be thought and that for the sake of which the thought exists is the same; for you cannot find thought without something that is, as to which it is uttered. And there is not, and never shall be, anything besides what is . . .”
If anyone can enlighten me as to the precise meaning of the above, I would be eternally grateful – and extremely impressed.