Discretion is the better part of valor

Caution is preferable to rash bravery. Said by Falstaff in King Henry the Fourth, Part One, by William Shakespeare.

It is better to be prudent than merely courageous, as in I'm signing up for the easy course first; discretion is the better part of valor. This proverb, a synonym of look before you leap, was first recorded in 1477. Charles Churchill put it in poetic form: “Even in a hero's heart, Discretion is the better part” (The Ghost, 1762). Shakespeare also used a form of it: “The better part of valor is discretion” (1 Henry IV, 5:4).