Portia from Shakespeare’s Merchant of Venice (1.2):
If to do were as easy as to know what were good to
do, chapels had been churches and poor men’s
cottages princes’ palaces. It is a good divine that
follows his own instructions: I can easier teach
twenty what were good to be done, than be one of the
twenty to follow mine own teaching. The brain may
devise laws for the blood, but a hot temper leaps
o’er a cold decree – such a hare is madness the
youth, to skip o’er the meshes of good counsel the
cripple.
Related to I see the better … Ovid, Petrarch, and Foscolo and I know what’s right, but I don’t do it.
Extracts 