A legal inquisition into the minds of men, considered by itself, all rational enquirers have agreed to condemn. What we want to ascertain is not the intention of the offender, but the chance of his offending again. For this purpose we reasonably enquire first into his intention. But, when we have found this, our task is but begun. This is one of our materials, to enable us to calculate the probability of his repeating his offence, or being imitated by others. Was this an habitual state of his mind, or was it a crisis in his history likely to remain an unique? What effect has experience produced on him; or what likelihood is there that the uneasiness and suffering that attend the perpetration of eminent wrong may have worked a salutary change in his mind? Will he hereafter be placed in circumstances that shall impel him to the same enormity? Precaution is, in its own nature, a step in a high degree precarious. Precaution that consists in inflicting injury on another will at all times be odious to an equitable mind. Meanwhile, be it observed that all which has been said upon the uncertainty of crime tends to aggravate the injustice of punishment for the sake of example.
Since the crime upon which I animadvert in one man can never be the same as the crime of another, it is as if I should award a grievous penalty against persons with one eye, to prevent any man in future from putting out his eyes by design.
One more argument, calculated to prove the absurdity of the attempt to proportion delinquency and suffering to each other, may be derived from the imperfection of evidence. The veracity of witnesses will, to an impartial spectator, be a subject of continual doubt. Their competence, so far as relates to just observation and accuracy of understanding, will be still more doubtful. Absolute impartiality it would be absurd to expect from them. How much will every word and every action come distorted by the medium through which it is transmitted? The guilt of a man, to speak in the phraseology of law, may be proved either by direct or circumstantial evidence. I am found near to the body of a man newly murdered. I come out of his apartment with a bloody knife in my hand, or with blood upon my clothes. If under these circumstances, and unexpectedly charged with murder, I falter in my speech, or betray perturbation in my countenance, this is in additional proof. Who does not know that there is not a man in England, however blameless a life he may lead, who is secure that he shall not end it at the gallows?