Who said "Progress requires us to question vhat ve think ve know."?

This quote is attributed to Chekov.

Progress requires us to question vhat ve think ve know. - Chekov

"Progress requires us to question vhat ve think ve know."

Chekov Education

"In Russia, ve have a saying: 'The best time to plant a tree vas twenty years ago. The second best time is now.'"

"Vhat is science vithout the courage to explore the unknown?"

"I have alvays found that friendship requires vork, but it is vork vorth doing."

"The human spirit is remarkably resilient - ve survive vhat ve must endure."

"Education opens doors."

"Education opens doors to endless possibilities."

"I ain't got the education you got, bub."

"You can't put a price on history."