On Liberty · ¶134

One of these examples, that of the sale of poisons, opens a new question; the proper limits of what may be called the functions of police; how far liberty may legitimately be invaded for the prevention of crime, or of accident. It is one of the undisputed functions of government to take precautions against crime before it has been committed, as well as to detect and punish it afterwards. The preventive function of government, however, is far more liable to be abused, to the prejudice of liberty, than the punitory function; for there is hardly any part of the legitimate freedom of action of a human being which would not admit of being represented, and fairly too, as increasing the facilities for some form or other of delinquency. Nevertheless, if a public authority, or even a private person, sees any one evidently preparing to commit a crime, they are not bound to look on inactive until…

John Stuart Mill · Walter Scott Publishing edition, with W. L. Courtney’s introduction · Gutenberg #34901
John Stuart Mill · Walter Scott Publishing edition, with W. L. Courtney’s introduction · Gutenberg #34901
Passage preview. Read in context for the complete text, notes and references.