"If a man knows not to which port he sails, no wind is favorable." —Seneca

"Mortal as I am, I know that I am born for a day. But when I follow at my pleasure the serried multitude of the stars in their circular course, my feet no longer touch the earth." —Ptolemy

"All the gold which is under or upon the earth is not enough to give in exchange for virtue." —Plato