ROSALIND From henceforth I will, coz, and devise sports. Let me see—what think you of falling in love? CELIA Marry, I prithee, do, to make sport withal; but love no man in good earnest, nor no further in sport neither than with safety of a pure blush thou mayst in honor come off again. (1.2.23-29)
From the play's very beginning, love is associated with foolishness and folly. Here, Rosalind and Celia think of "falling in love" as nothing more than an amusing "sport" that will help pass the time.
TOUCHSTONE Stand you both forth now: stroke your chins, and swear by your beards that I am a knave. CELIA By our beards (if we had them), thou art. TOUCHSTONE By my knavery (if I had it), then I were. But if you swear by that that not, you are not forsworn. No more was this knight, swearing by his honor, for he never had any, or if he had, he had sworn it away before ever he saw those pancakes or that mustard. (1.2.71-79)
Touchstone responds to Celia's accusation that he is a "knave" (foolish idiot). On the surface, Touchstone's response seems like total nonsense that's designed to make us laugh, which it does. (After all, what the heck do mustard and pancakes have to do with anything?) At the same time, Touchstone is the master of witty argumentation. Here, he points out that you can't be accused of lying if you swear on your honor and it turns out that you don't have any honor to begin with. Of course, if you would swear by what you do not have, you are dishonorable to begin with. Sigh.
TOUCHSTONE The more pity, that fools may not speak wisely what wise men do foolishly. (1.2.85-86)
After Rosalind tells Touchstone to stop talking, Touchstone complains that, in the court, fools' words have no merit, but sometimes fools are best able to comment on what is really going on. Although Touchstone ultimately obeys Rosalind, the truth is that Touchstone is a "licensed fool" (a guy who literally has a license to say whatever he wants without getting into trouble). Paid fools were pretty common in the households of royalty and nobility in Elizabethan England and they pop up all over in Shakespearean drama. Even though they clown around a lot, they're typically the smartest characters in the plays. For example, think of the Fool in King Lear and Feste in Twelfth Night.
Act 2, Scene 4
TOUCHSTONE We that are true lovers run into strange capers. But as all is mortal in nature, so is all nature in love mortal in folly. (2.4.53-55)
Usually, Touchstone is the first person to bag on a character who is lovesick. Here, though, his insights about the nature of love seem pretty optimistic. He says that, even though love makes us do silly things, it's also the thing that makes us human. That's pretty right on, don't you think?
Act 2, Scene 7
JAQUES O, that I were a fool! I am ambitious for a motley coat. DUKE SENIOR Thou shalt have one. JAQUES It is my only suit, Provided that you weed your better judgments Of all opinion that grows rank in them That I am wise. (2.7.44-49)
When Jaques says "O that I were a fool," he's mocking Touchstone for being a licensed fool who wears a "motley" coat (a multicolored get-up worn by court fools). Yet it also seems like Jaques really does wish he could be a licensed fool. As we know, Jaques sees himself as a philosopher with deep insight into human nature, but he's often mocked for his moody pretentiousness. So, does Jaques have what it takes to be a "fool"? Or is he just a poseur?
JAQUES A fool, a fool. I met a fool i' the forest, A motley fool. A miserable world! [...] When I did hear The motley fool thus moral on the time, My lungs began to crow like chanticleer That fools should be so deep-contemplative, And I did laugh sans intermission An hour by his dial. O noble fool! A worthy fool! Motley's the only wear. (2.7.12-13; 29-35)
Hmm. It sounds like Jaques bumped into Touchstone in the forest, don't you think? What's interesting is that melancholy Jaques is delighted by his encounter with Touchstone, even though he makes fun of Touchstone's "wisdom" here.
JAQUES Invest me in my motley. Give me leave To speak my mind, and I will through and through Cleanse the foul body of th' infected world, If they will patiently receive my medicine. [...] DUKE SENIOR Most mischievous foul sin, in chiding sin: For thou thyself hast been a libertine, As sensual as the brutish sting itself, And all the embossed sores and headed evils That thou with license of free foot hast caught Wouldst thou disgorge into the general world. (2.7.60-63; 66-71)
Jaques begs Duke Senior to appoint him as his official licensed fool so Jaques can point out everybody's flaws and cure "th' infected world "of all its problems. Duke Senior's not buying any of this nonsense—he points out that Jaques is more likely to infect the entire world with venereal disease ("embossed sores and headed evils") than to cure it of anything.
Act 3, Scene 2
For a taste: If a hart do lack a hind, Let him seek out Rosalind. If the cat will after kind, So be sure will Rosalind. Winter garments must be lined, So must slender Rosalind. They that reap must sheaf and bind; Then to cart with Rosalind. Sweetest nut hath sourest rind, Such a nut is Rosalind. He that sweetest rose will find Must find love's prick and Rosalind. This is the very false gallop of verses. Why do you infect yourself with them? (3.2.100-114)
When Touchstone finds out that Orlando has been littering the forest with bad poetry about Rosalind, he pokes fun at Orlando's rhyming, sing-songy verse by making up a poem of his own. Touchstone also manages to get in a few jabs about Rosalind while he's at it.
JAQUES The worst fault you have is to be in love. ORLANDO 'Tis a fault I will not change for your best virtue. I am weary of you. JAQUES By my troth, I was seeking for a fool when I found you. ORLANDO He is drowned in the brook. Brook but in, and you shall see him. JAQUES There I shall see mine own figure. ORLANDO Which I take to be either a fool or a cipher. (3.2.286-294)
Jaques bags on Orlando for being in love, but Jaques is no match for Orlando's quick wit. Here, Orlando tricks Jaques into admitting that he's a fool.
Act 4, Scene 1
I protest her frown might kill me. (4.1.115)
Say what? Rosalind's frown might "kill" Orlando? Not likely. Orlando has some pretty ridiculous ideas about what it means to be in love with a woman but Rosalind tries to straighten him out when she says "Men have died from time to/ time and worms have eaten them, but not for love."