Your recommended philosophy-guru is ZENO OF CITIUM.
Key fact: He taught in a stoa, the Athenian supermarket, and hence founded the school of philosophy called Stoicism.
Must have: An interest in everyday life, for it is there that you learn life's big lessons.
Key promise: An ability to face anything, no matter how disastrous.
Key peril: To be "stoical" is to turn your back on passion.
Most likely to say: "If you have integrity, no-one can harm you."
Least likely to say: "Forget prudence! It won't help you anyway."
That fits, as I am attracted by Stoicism and Epicureanism.
Find out who your ancient Greek guru is.