In this chapter, 1 I would like to draw attention to two quite distinct aspects of the theory of utility as it appears in Of the Limits of the Penal Branch of Jurisprudence (which, for the sake of brevity, I will refer to from now on as ‘ Of the Limits ’). 2 In the first part, I will attempt to shed some light on the status of the concept of utility in the manuscript. I will approach utility as the solution Bentham comes up with in order to make the legal system sort out some of the difficulties of practical reasoning. In so doing, I will examine questions that belong more directly to the field of practical philosophy than to that of legal theory. However, I will also suggest that this approach is useful in order to shed some light on Bentham’s legal theory. In the second part of this chapter, I will try to show that this role ascribed to utility – as a kind of allpurpose-tool in the field of practical reason – relies on a very specific account of the psychological life of several operators in the legal apparatus: the legislator, the judge and the legal subject. In fact, a remarkable feature of Of the Limits consists in its insistence on psychology rather than institutional analysis. More often than not, and in stark contradistinction with other works of the Benthamite corpus, the book depicts the legislator, the judge or the legal subject as individuals , endowed with psychological faculties and likely to fall into certain cognitive traps, rather than as institutions.