Who said “Discontent is the first necessity of progress.”?

“Our greatest weariness comes from work not done.”

“Discontent is the first step in the progress of a man or a nation.”

“Who with a little cannot be content, endures an everlasting punishment.”

“Let thy discontents be thy secrets.”

“Discontent is something that follows ambition like a shadow.”

“Show me a thoroughly satisfied man and I will show you a failure.”

“Genius is one percent inspiration, ninety-nine percent perspiration.”

“Restlessness is discontent and discontent is the first necessity of progress. Show me a thoroughly satisfied man and I will show you a failure.”

“I start where the last man left off.”

“Great ideas originate in the muscles.”

“There is no substitute for hard work.”