ONE: From political morality, unless founded on the immutable sentiments of mankind, no lasting advantage can be hoped. Whatever law deviates from these sentiments will encounter a resistance which will ultimately prevail over it, just in the same way as a force, however slight, if constantly applied, will prevail over a violent motion applied to any physical body.The credibility, therefore, of a witness must diminish in proportion to the hatred, friendship, or close connection between himself and the accused. More than one witness is necessary, because, so long as one affirms and another denies, nothing is proved, and the right which everyone has of being held innocent prevails.[140] The credibility of a witness becomes appreciably less, the greater the atrocity of the crime imputed,[66] or the improbability of the circumstances, as in charges of magic and gratuitously cruel actions. It is more likely, as regards the former accusation, that many men should lie than that such an accusation should be true, because it is easier for many men to be united in an ignorant mistake or in persecuting hatred than for one man to exercise a power which God either has not conferred or has taken away from every created being. The same reasoning holds good also of the second accusation, for man is only cruel in proportion to his interest to be so, to his hatred or[141] to his fear. Properly speaking, there is no superfluous feeling in human nature, every feeling being always in strict accordance with the impressions made upon the senses. In the same way the credibility of a witness may sometimes be lessened by the fact of his being a member of some secret society, whose purposes and principles are either not well understood or differ from those of general acceptance; for such a man has not only his own passions but those of others besides.
THREE:It is impossible to prevent all the disorders that may arise in the universal conflict of human passions. Their increase depends on that of population and on the crossings of private interests, which cannot be directed with geometrical exactness to the public welfare. In political arithmetic the calculation of probabilities must be substituted for mathematical exactness. Glance at the history of the world, and you will see disorders increase with the increase of the bounds of empire; thus national feeling being to the same extent diminished, the general inducement to crime increases with the greater interest of each individual in such disorders, and on this account the necessity for aggravating penalties ever continues to increase.
THREE:Given the necessity of the aggregation of mankind, and given the covenants which necessarily result from the very opposition of private interests, a scale of offences may be traced, beginning with those which tend directly to the destruction of society, and ending with acts of the smallest possible injustice committed against individual members of it. Between these extremes are comprised all the actions opposed to the public welfare which are called crimes, and which by imperceptible degrees decrease in enormity from the highest to the lowest. If the infinite and obscure combinations of human actions admitted of mathematical treatment, there ought to be a corresponding scale of punishments, varying from the severest to the slightest penalty. If there were an exact and universal scale of crimes and punishments, we should have an approximate and general test by[199] which to gauge the degrees of tyranny and liberty in different governments, the relative state of the humanity or wickedness of different nations. But the wise legislator will rest satisfied with marking out the principal divisions in such a scale, so as not to invert their order, nor to affix to crimes of the first degree punishments due to those of the last.Yet, supposing it were proved to-morrow that punishment fails entirely of the ends imputed to it; that, for example, the greater number of crimes are[80] committed by criminals who have been punished already; that for one chance of a mans reformation during his punishment there are a hundred in favour of his deterioration; and that the deterrent influence of his punishment is altogether removed by his own descriptions of it; shall we suppose for a moment that society would cease to punish, on the ground that punishment attained none of its professed ends? Would it say to the horse-stealer, Keep your horse, for nothing we can do to you can make you any better, nor deter others from trying to get horses in the same way?