Gluttony. Greed. Sloth. Pride. Envy. Lust. Anger. These are The Seven Deadly Sins, the vices of humankind that define immorality. But do these sins really represent moral failings, or are they simply important and useful biological functions that humans need to survive? Instead of being acts of immorality, are they really just a result of how our bodies, our psyches, and our brains in particular, are wired? In Guy Leschziner, a professor of neurology, dares to turn much of what society thinks of as morality on its head and to ask these controversial questions. Leschziner takes readers on an exploration of the Seven Deadly Sins as he looks at their neuroscientific and psychological bases, their origin in our genes, and, crucially, how certain medical disorders may give rise to them. He introduces us to patients whose physical and psychological conditions have given rise to behaviours that have for centuries been labelled as “sin” and how these behaviours might actually be evolutionary imperatives that preserve the tribe and ensure the wellbeing of our societies. In , a book certain to cause debate and raise controversy, Guy Leschziner, a writer who has explored the mysteries of our sleeping brains and the odd crossed wires of our five senses, asks whether these traits truly represent sin, or simply reflect our intrinsic drive to survive and thrive.