O sir, we quarrel in print, by the book, as you have books for good manners. I will name you the degrees. The first, the Retort Courteous; the second, the Quip Modest; the third, the Reply Churlish; the fourth, the Reproof Valiant; the fifth, the Countercheck Quarrelsome; the sixth, the Lie with Circumstance; the seventh, the Lie Direct. All these you may avoid but the Lie Direct; and you may avoid that, too, with an ‘if’. I knew when seven justices could not take up a quarrel, but when the parties were met themselves, one of them thought but of an ‘if’, as ‘If you said so, then I said so’, and they shook hands and swore brothers. Your ‘if’ is the only peacemaker; much virtue in ‘if’.
(V.iv.8192)

In Act V, scene iv, Touchstone delivers an account of a recent argument he has had. His anatomy of the quarrel, as this speech might be called, is a deftly comic moment that skewers all behavior that is “by the book,” whether it be rules for engaging an enemy or a lover (V.iv.81). The end of the speech, in which Touchstone turns his attentions to the powers of the word “if,” is particularly fine and fitting. “If” points to the potential of events in possible worlds. “If” allows slights to be forgiven, wounds to be salved, and promising opportunities to be taken. Notably, within a dozen lines of this speech, Duke Senior, Orlando, and Phoebe each usher in a new stage of life with a simple sentence that begins with that simple word.