MORE: When a man takes an oath, Meg, he’s holding his own self in his hands. Like water (cups hands) and if he opens his fingers then, he needn’t hope to find himself again.

Robert Bolt (1924-1995) English dramatist

A Man for All Seasons, play, Act 2 (1960)
    (Source)

Answering to his daughter Margaret, who is trying to convince him to swear to the Act of Succession so that he can be freed from the Tower. In the 1966 screenplay, the same dialogue is used.