Demosthenes, the Athenian orator and politician, was almost an exact contemporary of Aristotle, who is thought to have been born in 384 B.C., whereas the probable birth date given for Demosthenes is 382 B.C. Both died in 322 B.C.
The image is that of a Roman bust held by the Getty museum, and I gather the likeness (if it is a likeness) is based on an alleged Greek statue of Demosthenes.
Here are some quotations from Demosthenes. Almost all the quotation-sites on the Web have the same ones, although the translations sometimes differ slightly.
A man is his own easiest dupe, for what he wishes to be true he generally believes to be true.
(This may apply to a woman as well; not sure).
To remind a man of the good turns you have done him is very much like a reproach.
(This seems like very good advice, if hard to follow; just do what you imagine to be the good turn, but don’t remind the beneficiary of how allegedly well you behaved.)
What we wish, that we readily believe.
(Politicians seem to capitalize on this characteristic constantly, telling people what they wish to be so even when it is not so.)