Who said "Strength is not in the muscles but in the will."?

This quote is attributed to Gertrude Stein.

Strength is not in the muscles but in the will. - Gertrude Stein

"Strength is not in the muscles but in the will."

Gertrude Stein Strength

Novelist Poet American 1874–1946

"A rose is a rose is a rose."

"There is no there there."

"Everybody gets so much information all day long that they lose their common sense."

"You are all a lost generation."

"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."