Who said "The mind must be trained like an athlete trains the body."?

This quote is attributed to Carl Friedrich Gauss.

The mind must be trained like an athlete trains the body. - Carl Friedrich Gauss

"The mind must be trained like an athlete trains the body."

Carl Friedrich Gauss

Mathematician and Physicist German 1777–1855

"Mathematics is the queen of the sciences."

"I am still learning."

"It is not knowledge, but the act of learning, not possession but the act of getting there, which grants the greatest enjoyment."

"Talent is a flame. Genius is a fire."