As You Like It Foolishness and Folly Quotes Page 1

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. 

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.

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.