The Abraham Dilemma is a philosophical exploration, proposing a theory of religious or spiritual delusion. It includes several modern case histories, some protagonists deluded and some not. The focus on Abraham is his offering his son, Isaac, as a sacrifice to God. The hostility of some mental health professionals to the very notion of spirituality or religion is decried, as is the claim that spiritual ideas, ipso facto, are delusional.

Graham's central argument is collecting the elements of religious delusion in the ‘Five Factor Conception’: personal over-engagement/over-investment/over-identification (i.e. lack of insight); harmful consequences of unwarranted sorts (serious harm comes from belief); resistance to criticism (overwhelming conviction); faulty belief formation and normative misjudgement (‘even if this empirical belief is not false, the apparent subjective warrant for empirical beliefs is too strongly influenced and faultily biased’ – belief based on delusional evidence); and impairment in reflective self-control (unable to examine critically attitudes and beliefs). The implication is that ‘various mental disorders are often failures of proper moral habits of mind and behavior in people’.

Mental health professionals are specifically addressed. Unfortunately, the discussion on delusion is based on DSM-5, an epidemiological tool not suitable for delineating individual cases. In psychiatry, we identify delusion, a sign, and diagnose mental illness; delusion of itself does not constitute diagnosis. Our definition of delusion must include all delusions, not just religious – delusions are morally neutral; the term delusion should exclude beliefs in people who are not mentally ill. Form and content is an essential consideration for delusion and we need to make a clear distinction between delusion, a false belief, and hallucination, a false perception.

Was Abraham deluded? Graham writes: ‘If truth is told and humility assumed, we are in no position definitively to diagnose Abraham’. Graham decides that Abraham was deluded because his belief would have resulted in unwarranted harm – the ‘moral odiousness’ that he should sacrifice Isaac. From a psychiatric standpoint, that is not sufficient reason to identify delusion, and there is no supporting evidence for mental illness. Descriptive phenomenology, the bedrock of psychiatric diagnosis, depends on finding the personal meaning of thought or behaviour for the individual, and that, for Abraham, we can never do.

The features of the ‘Five Factor Conception’ are a refreshing restatement of the features of delusion and are applicable for spiritual or religious delusion. From the perspective of psychiatry, which must also consider delusions other than religious and must make diagnosis leading to treatment strategy, we need to retain our existing definition or the detailed features of delusion listed by Munro (Delusional Disorder: Paranoia and Related Illnesses; CUP, 1999).