useless trivia: What Word Means: A Sharpener?

Questions

"The important thing is not to stop -------------."- Albert Einstein (1875-1955)?

"If you can't say anything --------- about someone, sit right here by me."- Alice Lee Roosevelt Longworth?

"If you can't ----------, then get up and do something instead of lying there worrying. It's the worry that gets you, not the lack of sleep." - Dale Carnegie?

"The interpretation of --------- is the royal road to a knowledge of the unconcious activities of the mind."- Sigmund Freud?

"If you copy from one author it's ------------. If you copy from two it's research."- Wilson Mizner?