It is quite needless to add that if Malthus thus made short work of conjugal frauds he all the more strongly condemned that other preventive method, namely, the institution of a special class of professional prostitutes.[298] He would similarly have condemned the practice of abortion, of which scarcely anything was heard in his day, but which now appears like a scourge, taking the place of infanticide and the other barbarous practices of antiquity. Criminal law seems powerless to suppress it, and it has already received the sanction of a new morality. But apart from the question of immoral practices, did Malthus really believe that moral restraint as he conceived of it would constitute an effective check upon population? He doubtless was anxious that it should be so, and he tried to rouse men to a holy crusade against this worst of all social evils. “To the Christian I would say that the Scriptures most clearly and precisely point it out to us as our duty to restrain our passions within the bounds of reason.… The Christian cannot consider the difficulty of moral restraint as any argument against its being his duty.” (P. 452.) And to those who wish to follow the dictates of reason rather than the observances of religion he remarks: “This virtue [chastity] appears to be absolutely necessary in order to avoid certain evils which would otherwise result from the general laws of nature.” (P. 452.)[299] At bottom he was never quite certain as to the efficacy of moral restraint. The threatening hydra always peered over the fragile shield of pure crystal with which he had hoped to do battle.[300] He also felt that celibacy might not merely be ineffective, but would actually prove dangerous by provoking the vices it was intended to check. Its prolongation, or worse still its perpetuation, could never be favourable to good morals. Malthus was faced with a terrible dilemma, and the uncompromising ascetic is forced to declare himself a utilitarian philosopher of the Benthamite persuasion. He has now to condone those practices which satisfy the sexual instinct without involving maternity, although at an earlier stage he characterised them as vices. It seemed to him to be the lesser of two evils, for over-population[301] is itself the cause of much immorality, with its misery, its promiscuous living and licence. All of which is very true.[302] At the same time the rule of conduct now prescribed is no longer that of “perfect purity.” It is, as he himself says, the grand rule of utility. “It is clearly our duty gradually to acquire a habit of gratifying our passion, only in that way which is unattended with evil.” (P. 500.) These concessions only served to prepare the way for the Neo-Malthusians.