Full Idea
It behoves the legislator to understand the force of pleasures and pains, which is their value.
Gist of Idea
The value of pleasures and pains is their force
Source
Jeremy Bentham (Intro to Principles of Morals and Legislation [1789], IV.1)
Book Reference
Mill,John Stuart: 'Utilitarianism (including On Liberty etc)', ed/tr. Warnock,Mary [Fontana 1962], p.64