Shakespeare would have agreed with the Senate Intelligence Committee's conclusion that torture doesn't produce useful information
. At the end of Othello
, Gratiano says that "torments" will make Iago explain his villainy (5.2.312), but we don't see this, and Ludovico orders Cassio to torture Iago (5.2.377-79) for the same reason that Lucius orders that Aaron be tortured in Titus Andronicus
(5.3.178-82) and Benedick proposes torturing Don John in Much Ado About Nothing
(5.4.121-22)—as a punishment. In the only play in which we see torture used in an attempt at gaining intelligence, it gains nothing. King Lear
's Cornwall, Regan, and Goneril tie Gloucester to a chair and pull his beard to get him to tell them why he sent the king to Dover. But Gloucester doesn't reveal that Cordelia and French army are there, and even if he had, the villains knew this already. Having learned nothing, they blind Gloucester in a frenzy of sadism.
In The Merchant of Venice
, Portia alludes to the main reason torture doesn't result in reliable intelligence: torture victims will say what they think their torturers want to hear. Portia tells Bassanio she doesn't trust his protestations of love because "I fear you speak upon the rack, / Where men enforced do speak anything" (3.2.32-33).