The Myth of Mental Illness: Foundations of a Theory of Personal Conduct is a controversial book by Thomas Szasz. It is highly influential in the anti-psychiatry movement. In it, Szasz argues that mental illness is a social construct created by doctors, and the term can only be used as a metaphor given that an illness must be an objectively demonstrable biological pathology, whereas psychiatric disorders meet none of these criteria. What psychiatrists label mental illness is in fact nothing more than a deviation from the consensus reality or common morality, Szasz says.
He states that mental illness, madness and even many crimes are created or defined by cultural controls, morals and "real world" views of big science, religion and government, similar to heretics, pagans, and sinners before the industrial revolution. In parts he agrees with Wilhelm Reich, Alexander Lowen, R.D. Laing, Arthur Janov and Peter Breggin. All are psychiatrists, except Janov, who is a psychologist. Their views, theories and psychotherapies are opposed to and rejected by most MD and counselors in the 20th century. Szasz asserts that a positive, present and honest relationship is the basis of his therapy.
The book extends the arguments of Szasz's paper "The Myth of Mental Illness", first published in 1960. In it, Szasz argues that beliefs cannot be caused by brain disease, although such artifacts as visual (or hearing) defects can.