In an influential and historical work of literature, titled "On Liberty", John Stuart Mill proposed a general doctrine which can be termed the "harm principle" -The works of Mill were largely influential in the birth of American Constitutional Government. The harm principle is a straightforward philosophy restraining the scope of criminal laws by the following means:
1. Acts may be rightfully criminalized only when they inflict concrete harms on specific individuals.
2. With the exception of protecting children and otherwise incompetent persons, it is unjust to criminalize acts merely on the grounds of preventing potential harm (i.e. harm that is not immenent, meaning preemptive or preventative criminalization is unjust)
3. It is unjust to criminalize a behavior merely because the idea of it is offensive to others (i.e. socially disapproved)
This principle has been one of the main premises underlying my own advocacy for repealing current drug laws.
The Utilitarian Approach:
Mill advocates the harm principle from a utilitarian standpoint, a system of ethics in which rules or laws are made by considering the ultimate results of the given rule (the ultimate proportion of positive to negative consequences), and then contrasting this with the ultimate results of not establishing the rule (again, determined by the aforementioned formula).
The morally justified choice is always that which, in the long term, provides the greatest aggregate margin or sum by which human pleasure exceeds human pain or suffering. Utilitarianism is essentially a means of quantifying the moral or ethical merit of a given course of action.