...now a king, and now is clay

Thou art not holy to belie me so;
I am not mad: this hair I tear is mine;
My name is Constance; I was Geffrey's wife;
Young Arthur is my son, and he is lost:
I am not mad: I would to heaven I were!
For then, 'tis like I should forget myself:
O, if I could, what grief should I forget!
Preach some philosophy to make me mad,
And thou shalt be canonized, cardinal;
For being not mad but sensible of grief,
My reasonable part produces reason
How I may be deliver'd of these woes,
And teaches me to kill or hang myself:
If I were mad, I should forget my son,
Or madly think a babe of clouts were he:
I am not mad; too well, too well I feel
The different plague of each calamity.

This is "Catch 22"

Quote from RSC King John.
Constance- mother of Prince Arthur. 
PS - best value seat in the house (The Swan) Standing on top row far right - £5:00. Great view and the ability to walk around during the show!