Who said "Real motivation comes from moral conviction."?

This quote is attributed to Meathead.

Real motivation comes from moral conviction. - Meathead

"Real motivation comes from moral conviction."

Meathead Motivation

"You gotta understand the dialectical materialism of the situation, Archie"

"Love is a beautiful thing, man, it's like the revolution of the heart"

"Education is the key to enlightenment and social change"

"Peace will come when we stop perpetuating the military-industrial complex"

"I believe in working hard for what you want."

"Never underestimate the power of determination."

"I don't need a reason to fight."

"The most important thing is the mission. Nothing else matters."