What is meant by And melancholy is the nurse of frenzy in The Taming of the Shrew by William Shakespeare?

Answer 1

The full quotation is:

Your honour's players, hearing your amendment,

Are come to play a pleasant comedy;

For so your doctors hold it very meet,

Seeing too much sadness hath congeal'd your blood,

And melancholy is the nurse of frenzy.

Therefore they thought it good you hear a play

And frame your mind to mirth and merriment,

Which bars a thousand harms and lengthens life.

In other words, watching a funny play is good for your health. To understand the medical theory going on here, you have to know something about the four humours, especially the black bile and blood. These two substances were supposed to regulate a person's temperament and behaviour: lots of blood made a person sanguine, happy, optimistic, but lots of black bile made a person melancholic, depressed and unhappy. The diagnosis is that "too much sadness hath congeal'd [Sly's] blood" which stops the blood from making him happy. His melancholy is taking over.

Psychiatry was easier then.

The messenger here employs a metaphor: he says melancholy is a nurse to frenzy. In the same way as a nurse helps a person grow strong and healthy, melancholy encourages and strengthens frenzied, desperate and erratic behaviour.