Fortune's fool
Benvolio:
Romeo, away, be gone!
The citizens are up, and Tybalt slain.
Stand not amaz'd, the Prince will doom thee death
If thou art taken. Hence be gone, away!
Romeo:
O, I am fortune's fool!
Lear:
I am even
The natural fool of fortune.
Timon:
You fools of fortune. . . .
Foolishness fascinated the Bard and his audience; the number of contemporary proverbs about fools is stunning. "A fool's bolt [arrow] is soon shot"; "No fool to [like] the old fool"; "Either a fool or a physician"; "A fool and his money be soon at debate"; "The fool doth think he is wise, but the wise man knows himself to be a fool" (that one's inherited from Socrates); "The first chapter of fools is to hold themselves wise"; "As the fool thinks, so the bell clinks"; "A fool's paradise"; "Fat as a fool"; "Two fools in one house are too many"—just to mention a few.
Shakespeare's phrase "fortune's fool" seems to be his invention, although it has proverbial kin: "Fortune favors fools"; "God sends fortune to fools"; and "Fools have fortune," all of which date from the mid-sixteenth century. In Shakespeare's hands, however, the sentiment of all these proverbs is inverted. Fortune is not bestowed on fools; men are the slaves Fortune makes fools of. Romeo, for example, simply by defending himself against Tybalt, a Capulet and therefore a blood enemy, becomes an outlaw. Caught up in a design he is powerless to affect, Romeo feels like fortune's puppet.