What are, in general, the proper punishments for crimes? Is the punishment of death really useful, or necessary for the safety or good order of society? Are tortures and torments consistent with justice, or do they answer the end proposed by the laws? Which is the best method of preventing crimes? Are the same punishments equally useful at all times? What influence have they on manners? These problems should be solved with that geometrical precision, which the mist of sophistry, the seduction of eloquence, and the timidity of doubt, are unable to resist.
If I have no other merit than that of having first presented to my country, with a greater degree of evidence, what other nations have written, and are beginning to practice, I shall account myself fortunate; but if, by supposing the rights of mankind and of invincible truth, I shall contribute to save from the agonies of death one unfortunate victim of tyranny, or of ignorance, equally fatal; his blessing and tears of transport, will be sufficient consolation to me for the contempt of all mankind.
Chapter 12: Of the Intent of Punishments
From the foregoing considerations it is evident, that the intent of punishments, is not to torment a sensible being, nor to undo a crime already committed. Is it possible that torments and useless cruelty, the instruments of furious fanaticism, or the impotency of tyrants, can be authorized by a political body? which, so far from being influenced by passion, should be the cool moderator of the passions of individuals. Can the groans of a tortured wretch recall the time past, or reverse the crime he has committed?
The end of punishment, therefore, is no other, than to prevent the criminal from doing further injury to society, and to prevent others from committing the like offence. Such punishments, therefore, and such a mode of inflicting them, ought to be chosen, as will make the strongest and most lasting impressions on the minds of others, with the least torment to the body of the criminal.
Chapter 13: Of the Credibility of Witnesses
To determine exactly the credibility of a witness, and the force of evidence, is an important point in every good legislation. Every man of common sense, that is, every one whose ideas have some connection with each other, and whose sensations are conformable to those of other men, may be a witness; but the credibility of his evidence will be in proportion as he is interested in declaring or concealing the truth. Hence it appears, how frivolous is the reasoning of those, who reject the testimony of women on account of their weakness; how puerile it is, not to admit the evidence of those who are under sentence of death, because they are dead in law; and how irrational to exclude persons branded with infamy: for in all these cases they ought to be credited, when they have no interest in giving false testimony.
The credibility of a witness, then, should only diminish in proportion to the hatred, friendship, or connections, subsisting between him and the delinquent. One witness is not sufficient; for whilst the accused denies what the other affirms, truth remains suspended, and the right that every one has to be believed innocent, turns the balance in his favor.
The credibility of a witness is the less, as the atrociousness of the crime is greater, from the improbability of its having been committed; as in cases of witchcraft, and acts of wanton cruelty. The writers on penal laws have adopted a contrary principle, viz. that the credibility of a witness is greater, as the crime is more atrocious. Behold their inhuman maxim, dictated by most cruel of imbecility. In atrocissimis, leviores conjecturae sufficiunt & licet judici jura transgredi. Let us translate this sentence, that mankind may see one of the many unreasonable principles to which they are ignorantly subject. In the most atrocious crimes the slightest conjectures are sufficient, and the judge is allowed to exceed the limits of the law. The absurd practices of legislators, are often the effect of timidity, which is a principal source of the contradictions of mankind. The legislators, (or rather lawyers, whose opinions, when alive, were interested and venal, but which after their death become of decisive authority, and are the sovereign arbiters of the lives and fortunes of men) terrified by the condemnation of some innocent person, have burthened the law with pompous and useless formalities, the scrupulous observance of which will place anarchical impunity on the throne of justice; at other times, perplexed by atrocious crimes of difficult proof, they imagined themselves under a necessity of superseding the very formalities established by themselves; and thus, at one time, with despotic impatience, and at another with feminine timidity, they transform their solemn judgments into a game of hazard.
But to return. In the case of witchcraft, it is much more probable, that a number of men should be deceived, than that any person should exercise a power which God hath refused to every created being. In like manner, in cases of wanton cruelty, the presumption is always against the accuser, for no man is cruel without some interest, without some motive of fear or hate. There are no spontaneous or superfluous sentiments in the heart of man; they are all the result of impressions on the senses.
The credibility of a witness may also be diminished, by his being a member of a private society, whose custom and principles of conduct are either not known, or are different from those of the people. Such a man has not only his own passions, but those of the society of which he is a member.
Finally, the credibility of a witness is null, when the question relates to the words of a criminal; for the tone of voice, the gesture, all that precedes, accompanies and follows, the different ideas which men annex to the same words, may so alter and modify a man's discourse, that it is almost impossible to repeat them precisely in the manner in which they were spoken. Besides, violent and uncommon actions, such as real crimes, leave a trace in the multitude of circumstances that attend them, and in their effects; but words remain only in the memory of the hearers, who are commonly negligent or prejudiced. It is infinitely easier then to found an accusation on the words, than on the actions of a man; for in these, the number of circumstances, urged against the accused, afford him the variety of means of justification.
Chapter 14: Of Evidence and the Proofs of a Crime, and of the Form of Judgment
The following general theorem is of great use in determining the certainty of a fact. When the proofs of a crime are dependent on each other, that is, when the evidence of each witness, taken separately, proves nothing; or when all the proofs are dependent upon one, the number of proofs neither increase nor diminish the probability of the fact; for the force of the whole is no greater than the force of that which they depend; and if this fails, they all fall to the ground. When the proofs are independent on each other, the probability of the fact increases in proportion to the number of proofs; for the falsehood of one does not diminish the veracity of another.
It may seem extraordinary, that I speak of probability with regard to crimes, which, to deserve a punishment, must be certain. But this paradox will vanish, when it is considered, that, strictly speaking, moral certainty is only probability; but which is called a certainty, because every man in his senses assents to it from an habit produced by the necessity of acting, and which is anterior to all speculation. That certainty which is necessary to decide, that the accused is guilty, is the very same which determines every man in the most important transactions of his life.
The proofs of a crime may be divided into two classes, perfect and imperfect. I call those perfect which exclude the possibility of innocence; imperfect, those which do not exclude this possibility. Of the first, one only is sufficient for condemnation; of the second, as many are required as form a perfect proof; that is to say, that though each of these, separately taken, does not exclude the possibility of innocence, it is nevertheless excluded by their union. It should be also observed, that the imperfect proofs, of which the accused, if innocent, might clear himself, and does not, become perfect.
But it is much easier to feel this moral certainty of proofs, than to define it exactly. For this reason, I think it an excellent law which establishes assistants to the principal judge, and those chosen by lot; for that ignorance, which judges by its feelings, is less subject to error, than the knowledge of the laws, which judges by opinion.