Russel

“One swallow does not make a summer, neither does one fine day; similarly one day or brief time of happiness does not make a person entirely happy.”
― Aristotle, The Nicomachean Ethics

“To teach how to live without certainty, and yet without being paralyzed by hesitation, is perhaps the chief thing that philosophy, in our age, can still do for those who study it.”
― Bertrand Russell, A History of Western Philosophy