The Republic - pg. 178

"Well, it was on account of this," I said, "foreseeing it then,
that we were frightened; but, all the same, compelled by
the truth, we said that neither city nor regime will ever
become perfect, nor yet will a man become perfect in the
same way either, before some necessity chances to constrain
those few philosophers who aren't vicious, those now called
useless, to take charge of a city, whether they want to or not,
and the city to obey; or a true erotic passion for true philosophy
flows from some divine inspiration into the sons of those who
hold power or the office of king, or into the fathers themselves.
I deny that there is any reason why either or both of these things
is impossible. If that were the case we would justify by laughed
at for uselessly saying things that are like prayers. Or isn't that so?"