A reply to Fransisco Vergara's attack on Halévy's interpretation of Bentham in Philosophy, January, 1998. Vergara had argued that Halévy was mistaken in interpreting Bentham's principle of utility as a psychological law as well as the ethical greatest happiness principle. Mongin and Sigot show that Halévy correctly interpreted Bentham's texts and that the psychological law is necessary to Bentham's legal theory, economics and politics; they also argue that it is incorrect to confuse the principle of utility with a theory of universal selfishness, and that this misunderstanding underlies Vergara's mistaken picture of both Halévy and Bentham.