Psychotherapists are rediscovering concepts previously stated by poets, philosophers, and theologians, and elevating them to the status of science sometimes surprisingly little altered from their traditional form (11). The notion of man's sinfulness is such a concept, though it remains latent in modern psychological theory. What were the factors in the disappearance of the concept of sin? Perhaps punishments became too severe, and we “threw out the baby along with the bathwater.” Perhaps we grew wiser, and stopped imputing a variety of evils to man's sinfulness in a way that reflected mainly guilt. Partly, however, we elevated many sins to the status of crimes and deluded ourselves that unwieldy bureaucracies could achieve what the individual conscience could not. Finally, the emergence of so-called rational psychology and of so-called scientific medicine dealt a death-blow to sin by enabling us to believe that human behaviour was there to be described, categorized and labelled, rather than morally evaluated and judged for its effect on fellow-man. Freud helps us understand sinful behaviour. He shows how it is often the result, rather than the cause, of feelings of guilt. He traces man's sinfulness to ambivalence in his relationship to a worldly father. Melanie Klein, in her mother-centred psychology, connects ambivalence to ego splitting, attendant on the death instinct, and implies that man's aggression is biologically innate and his sinfulness inevitable. Winnicott pays special attention to a therapist's hatred of his patient, implying that knowing and understanding one's hatred defuses it in part, and frees up an individual to a more positive and creative life style, There is a parallel here with the theological notion of confession of sins with atonement and restitution. Narcissism is the psychological word for human egocentricity and we, as psychotherapists, are beginning to discover its importance, as did the philosophers and theologians in centuries past. Winnicott's discussion of social concern is a useful polarity to human narcissism, and mindful of his analysis of its etiology we can add social concern to the list of objectives for intensive psychotherapy practice. Is aggression innate and instinctual, or attendant on frustration in the infant-mother relationship? To view it as attendant on frustration is more acceptable, but tends to get us off the hook of moral culpability. Balint's concept of a basic fault is helpful here in that it has a bedrock quality analogous to the older concept of original sin, but somehow seems more scientific and more subject to rational inquiry and study. The basic fault is a pervasive and recurring sense of having been failed by someone sometime, in a way that is only partially reversible in its damaging effects. Psychotherapists should bring a concept of sin back into their work and emphasize personal moral culpability and accountability as vital to mental health. Technical modifications in line with this theoretical revision would be a more active, warm and empathic therapeutic manner, more attention to personal growth as a therapeutic aim, and relaxed criteria for determining who may benefit from psychotherapy. Perhaps in time we can bring ourselves to say with Menninger, “If the concept of personal responsibility and answerability of ourselves and for others were to return to common acceptance, hope would return to the world with it.”