He that strives with his enemy affords him a living sustenan... - Plutarch

"He that strives with his enemy affords him a living sustenance and education."

Plutarch

Historian Biographer Greece (Chaeronea) 46–120

More from Plutarch

"The mind is not a vessel to be filled, but a fire to be kindled."

"What we achieve inwardly will change outer reality."

"Be kind and merciful. Let no one ever come to you without leaving better and happier."

"Know thyself."