2 quotes for yesterday and today from the founder of the Stoic school of philosophy:

One conquers the world by conquering oneself.

All things are parts of one single system, which is called nature; the individual life is good when it is in harmony with nature.  

Zeno of Citium (334 BCE-262 BCE), Zeno of Citium; was a Hellenistic philosopher of Phoenician origin from Citium (Κίτιον, Kition), Cyprus. Zeno was the founder of the Stoic school of philosophy, which he taught in Athens from about 300 BC.