Even though their views differ on what constitutes the proper relationship between morality and the law, Aquinas, J.S. Mill and Brentano all agree that the state is morally justified in inflicting punishment on those who are found guilty of infringing state law and committing crime. Punishment is necessary, they argue, for the purposes of bringing about law compliance and a better society. Punishment, however, steps in after the law has not been complied with and, even when transacted, punishment is no guarantee of any moral betterment in society. Notwithstanding the different moral theories that Aquinas, Mill and Brentano elaborate, this paper argues that each of these authors hold an a priori moral conviction in the state's justification of punishment, but this cherished conviction can be called into question on practical, moral and state grounds.