All is flux, nothing is stationary.

You cannot step into the same river twice.

There is exchange of all things for fire and of fire for all things, as there is of wares for gold and of gold for wares.

To God all things are fair and good and right, but men hold some things wrong and some right.

Of all whose words I have heard, no one attains to this, to know that wisdom is apart from all.

I am what libraries and librarians have made me, with little assistance from a professor of Greek and poets

God is day and night, winter and summer, war and peace, surfeit and hunger.