Who said "Strength is not measured by physical power alone."?

This quote is attributed to Professor X.

Strength is not measured by physical power alone. - Professor X

"Strength is not measured by physical power alone."

Professor X Strength

"Mutants. Since the discovery of their existence they have been regarded with fear and suspicion by humanity."

"We are the future, Charles, not them. They no longer matter."

"Just because someone stumbles and loses their way doesn't mean they're lost forever."

"What we have to fear is fear itself."

"Strength comes from within."

"A woman should be proud of who she is."

"A strong woman can overcome anything."

"The only thing I'm good at is killing."