For 10 points, name this school of philosophy that was founded by Zeno of Citium, which stressed the importance of internal gratification rather than material success.
According to proponents of this school of philosophy, truth can be distinguished from even the most fallacious statement, even if only a semantic approximation is available.  This school's central belief of the "certainty of truth" can be seen in the writings of Boethius, Epictetus, Seneca the Younger, and the man who wrote that one must be "free of secular desire" in his Meditations, Marcus Aurelius. For 10 points, name this school of philosophy that was founded by Zeno of Citium, which stressed the importance of internal gratification rather than material success.
According to proponents of this school of philosophy, truth can be distinguished from even the most fallacious statement, even if only a semantic approximation is available.  
Stoicism