Never trade certainty for hope. [ Proverb ]

To believe with certainty we must begin to doubt. [ Stanislaus ]

The present is the only reality and the only certainty. [ Arthur Schopenhauer ]

The basis of every scandal is an absolutely immoral certainty. [ Oscar Wilde, A Woman of No Importance ]

He is no wise man that will quit a certainty for an uncertainty. [ Johnson ]

In regard to virtue, each one finds certainty by consulting his own heart. [ Renan ]

Fame is a vapor; popularity an accident; riches take wings; the only certainty is oblivion. [ Horace Greeley ]

From principles is derived probability; but truth, or certainty, is obtained only from facts.

Every alphabet now in use may be traced with historical certainty to one original, the Phoenician or Syriac. [ Chatfield ]

Jealousy lives upon doubt, and comes to an end or becomes a fury as soon as it passes from doubt to certainty. [ La Rochefoucauld ]

Our understandings are always liable to error. Nature and certainty is very hard to come at; and infallibility is mere vanity and pretense. [ Marcus Antoninus ]

In all instances where our experience of the past has been extensive and uniform, our judgment concerning the future amounts to moral certainty. [ Beattie ]

Monotony, even under circumstances least favourable to the usual elements of happiness, becomes a happiness in itself, growing, as it were, unseen, out of the undisturbed certainty of peculiar customs. [ Lord Lytton ]

The human mind, in proportion as it is deprived of external resources, sedulously labours to find within itself the means of happiness, learns to rely with confidence on its own exertions, and gains with greater certainty the power of being happy. [ Zimmermann ]