Quote 1
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.
Quote 2
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?
Quote 3
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.