But one of the main reasons of this tendency is an error of psychological perspective, whereby men have forgotten the profound differences of the ideas, habits, and sentiments of the various social strata, concerning which I have spoken above. Through this forgetfulness the honest and instructed classes confound their own idea of the penal law, and the impression it makes upon them, with the idea and the impression of the social classes from which the majority of criminals are recruited. This has been remarked upon by Beccaria, Carmignani, and Holtzendorff amongst the classical criminalists, and by Lombroso and others of the new school who have studied the slang and literature of criminals, which are their psychological mirror. Again, it is forgotten that for the higher classes, apart from their physical and moral repugnance against crime, which is the most powerful repelling force, there is the fear of public opinion, almost unknown amongst the classes which <p 101>have stopped short at a lower stage of human evolution. For the higher classes one example may suffice. It is the fact observed upon by Mr. Spencer, that gambling debts and Stock Exchange bargains are scrupulously discharged, though for them there is neither penal obligation nor evidence in writing. And it may be added that imprisonment for debt never promoted the fulfilment of contracts, nor has its abolition discouraged it. As for the lower classes, one visit to a prison suffices. There, if you ask a prisoner why the punishment did not deter him from the crime, you generally get no answer, because he has never thought about it. Or else he replies, as I have often found, that ``if you were afraid of hurting yourself when you went to work, you would give up working.'' These indeed are what one would expect to be the feelings prevailing amongst the lower social strata, to whom honest sentiments and ideas, which for us are traditional and organic, come very late--just as Mr. Stanley observed that the people in Central Africa are only now beginning to employ stone guns, which in past ages were used in Europe. Another fallacy which helps to strengthen confidence in punishments is that the effect of exceptional and summary laws is treated on the same basis as that of the ordinary codes, slow and uncertain in their procedure, which saps all their force by the chance of immunity, and the interval between the unlawful act and its legal consequence.