Question: In Act 3, Scene 1, how does Feste sum up for Viola/Cesario his role as a
Fool? What is Viola/Cesario's estimation of Feste's qualities and speech?
Feste's role as a fool in Lady's Olivia's court is to corrupt her words. He specifically says that he's not a fool because Olivia wants a fool as much as she desires a husband, which is not at all. So instead of calling himself a fool, he dubs himself the corrupter of words. Or in today's language, it means turning words into whores. Words turn into whores because they can change so easily. You can use them for different meanings and instances. You can play with them, dress them up, dress them down. Use them as a weapon or way to convince someone. This can be both dangerous and hard for the Fool. He must be wary of what he says and whom he says it to. He cannot take light of words (even if it sounds like he does) because they can turn on him and the Fool recognizes that.
The Fool and Viola discuss this in Act 3, Scene 1 lines 11-15.
FESTE You have said, sir. To see this age! A sentence is but a cheveril glove to a good wit. How quickly the wrong side may be turned outward!
VIOLA Nay, that's certain. They that dally nicely with words may quickly turn them wanton.
They are saying that words can change fast if you play with them often. If you're not careful you can get burned.
At the end of the conversation Viola realizes that the Fool has a much more difficult job than she or any of the others have seen before. They all assume it is an easy life, making jokes out of life. But the opposite is true because due to the words having different meanings to different people finding the answer or truth can be a challenge. She says this in lines 59 to 68.
VIOLAThis fellow is wise enough to play the fool
But wise men folly- fall'n, quite taint their wit.
Viola says that this is a wise man's job because only the wise can successfully be a Fool. Many wise men have tried to be funny or witty but it doesn't work because they don't understand the words. They understand they can change and become new ones. They also don't understand that people can be offended by anything and the Fool must be careful about what he is saying to each of his listeners. The wise men probably try to hard at the Fool's job and mess up because they think about it too much.
This passage is of important significance because it shows that not all things are as they seem. In Act 1 Viola as Cesario tries to gain her trust, while Olivia intrigued by her. Olivia does not see beyond the facade and the reasons, she sees just wants she wants to. All the characters of the play and even the audience assumed that the Fool was just that, a fool. But he isn't. He's tricked everyone into thinking that he's a just a jester, one dressed in bright colors and likes to play instruments. If only they knew that the Fool is watching and listening to them, their conversations and their actions they might be more careful around the Fool because he might use his knowledge of them to his benefit. Viola sees this and I think stores it away and perhaps might use this warning of words a future reference. And also the fact (she knows this very well) that what you see is not always what you get, that truth may be hidden behind a facade and if only you look for it, will it reveal itself.