Persuasion is better than force.

Aesop (620?-560? BC) Legendary Greek storyteller

Fables [Aesopica], “The Wind and the Sun” (6th C BC) [tr. James (1848)]
    (Source)

Alternate translation: "Kindness effects more than Severity." [tr. Jacobs (1894)]

Alternate translation: "Persuasion is often more effectual than force."