Perhaps the most moving statement of the importance of inner honour comes from Hermione, in The Winter's Tale, as she stands accused of adultery, and threatened with death:

But yet hear this--mistake me not: for life,
I prize it not a straw, but for mine honour,
Which I would free--if I should be condemned
Upon surmises, all proofs sleeping else,
But what your jealousies awake, I tell you,
'Tis rigour, and not law.
(3.2.107-12)