Alexander wept when he heard ...

Alexander wept when he heard from Anaxarchus that there was an infinite number of worlds; and his friends asking him if any accident had befallen him, he returns this answer: \
Alexander wept when he heard from Anaxarchus that there was an infinite number of worlds; and his friends asking him if any accident had befallen him, he returns this answer: "Do you not think it a matter worthy of lamentation that when there is such a vast multitude of them, we have not yet conquered one?

Quotes from the same author

Silence at the proper season is wisdom, and better than any speech.
Know how to listen, and you will profit even from those who talk badly.
To make no mistakes is not in the power of man; but from their errors and mistakes the wise and good learn wisdom for the future.
I don't need a friend who changes when I change and who nods when I nod; my shadow does that much better.
What we achieve inwardly will change outer reality.