William Blackstone, Commentaries on the Laws of England

Book IV, Chapter 1 and Chapter 2

A CRIME, or misdemeanor, is an act committed, or omitted, in violation of a public law, either forbidding or commanding it. This general definition comprehends both crimes and misdemeanors ; which, properly speaking, are mere synonymous terms : though, in common usage, the word, "crimes," is made to denote such offences as are of a deeper and more atrocious dye ; while smaller faults, and omissions of less consequence, are comprised under the gentler name of "misdemeanors" only.

THE distinction of PUBLIC WRONGS from private, of crimes and misdemeanors from civil injuries, seems principally to consist in this: that private, or civil injuries, are an infringement or privation of the civil rights which belong to individuals, considered merely as individuals; public wrongs, or crimes and misdemeanors, are a breach and violation of the public rights and duties, due to the whole community, considered as a community, in its social aggregate capacity. As if I detain a field from another man, to which the law has given him a right, this is a civil injury, and not a crime; for here only the right of an individual is concerned, and it is immaterial to the public, which of us in possession of the land: but treason, murder, and robbery are properly ranked among crimes; since, besides the injury done to individuals, they strike at the very being of society; which cannot possibly subsist, where actions of this sort are suffered to escape with impunity.

IN all cases the crime includes an injury: every public offence is also a private wrong, and somewhat more; it affects the individual, and it likewise affects the community. Thus treason in imagining the king's death involves in it conspiracy against an individual, which is also a civil injury: but as this species of treason in its consequences principally tends to the dissolution of government, and destruction thereby of the order and peace of society, this denominates it a crime of the highest magnitude. Murder is an injury to the life of an individual; but law of society confiders principally the loss which the state sustains by being deprived of a member, and the pernicious example thereby set, for others to do the like. Robbery may be considered in the same view: it is an injury to private property; but, were that all, a civil satisfaction in damages might atone for it : the public mischief is the things, for the prevention of which our laws have made it a capital offence. In these gross and atrocious injuries the private wrong is swallowed up in the public : we seldom hear any mention made of satisfaction to the individual; the satisfaction to the community being so very great. And indeed, as the public crime is not otherwise avenged than by forfeiture of life and property, it is impossible afterwards to make any reparation for the private wrong; which can only be had from the body or goods of the aggressor. . . .

HAVING . . . considered in general the nature of crimes, and punishments, we are next led, in the order of our distribution, to inquire what persons are, or are not, capable of committing crimes; or, which is all one, who are exempted from the censures of the law upon the commission of those acts, which in other persons would be severely punished. In the process of which inquiry, we must have recourse to particular and special exceptions: for the general rule is, that no person shall be excused from punishment for disobedience to the laws of his country, excepting such as are expressly defined and exempted by the laws themselves.

ALL the several pleas and excuses, which protect the committer of a forbidden act from the punishment which is otherwise annexed thereto, may be reduced to this single consideration, the want or defect of will. An involuntary act, as it has no claim to merit, so neither can it induce any guilt: the concurrence of the will, when it has its choice either to do or to avoid the fact in question, being the only thing that renders human actions either praiseworthy or culpable. Indeed, to make a complete crime, cognizable by human laws, there must be both a will and an act. For though, in foro conscientiae [in the court of conscience], a fixed design or will to do an unlawful act is almost as heinous as the commission of it, yet, as no temporal tribunal can search the heart, or fathom the intentions of the mind, otherwise than as they are demonstrated by outward action, it therefore cannot punish for what it cannot know. For which reason in all temporal jurisdictions an overt act, or some open evidence of an intended crime, is necessary, in order to demonstrate the depravity of the will, before the man is liable to punishment. And, as a vicious will without a vicious act is no civil crime, so on the other hand, an unwarrantable act without a vicious will is no crime at all. So that to constitute a crime against human laws, there must be, first, a vicious will; and, secondly, an unlawful act consequent upon such vicious will.