Losing the Soul, Finding Ourselves

For most of Western history, the soul was the master key to human nature, the invisible essence that thinkers from Plato to Descartes believed set us apart from animals, grounded morality, and housed the mind itself. Psychology, in its earliest form, was literally the “study of the soul.” Mental illness was treated as a disturbance of this fragile inner essence. Even as modern science began to peel the mind away from metaphysics, the soul proved stubborn, clinging to public imagination long after psychology turned decisively toward neurons, behavior, and cognition.

But is the soul—and all its promised magic—actually real? One particularly memorable attempt to prove it came in 1907, when a Massachusetts physician, Duncan MacDougall, built an oversized industrial scale and placed dying patients atop it to see whether a soul might leave a trace on the balance sheet of physics. When the scale dipped a mere 21 grams for one patient, MacDougall declared victory. The fact that other patients showed no such drop, or that the equipment may simply have shifted, did little to dampen the myth. The “21-gram soul” survives today as one of history’s more whimsical reminders that flimsy data can enjoy a remarkably vigorous afterlife.

Into this rich, strange, and often sentimental territory steps evolutionary biologist and psychologist David P. Barash with The Soul Delusion (Bloomsbury Academic 2025), a brisk, incisive, and often exhilarating demolition of the soul as an explanatory concept. Barash writes with an elegance and clarity that make even his most devastating arguments feel almost tender. This is a book that does not merely critique the idea of the soul—it disassembles it, examines the parts, and shows how little is left when the metaphysics are stripped away and held up to empirical light.

Source: David P. Barash / Bloomsbury, 2025

Barash surveys the bewildering array of soul-concepts—immortal essence, seat of consciousness, divine spark—and argues that all of them clash with everything we know about how brains, bodies, and evolution actually work. The soul, in his telling, is precisely what the historian and best-selling author of Sapiens Yuval Noah Harari would call “inter-subjective”: a compelling story we tell one another, powerful because it is widely shared, not because it is objectively true.

What elevates The Soul Delusion above a simple debunking is Barash’s insistence that belief in the soul is not merely delusive—it can be harmful. He shows how the conviction that embryos possess immortal souls undergirds political movements that endanger women’s health; how soul-belief has justified grotesque cruelty toward animals on the grounds that only humans have this inner essence; and how the promise of an afterlife has, historically, made people more willing to sacrifice this one. The soul, in short, is not a harmless metaphor. It has consequences.

But Barash is equally passionate about what a soul-free worldview might offer. Drawing on poetry, psychology, and evolutionary biology, he argues that letting go of the soul frees us from the fear of hell, from magical thinking about near-death experiences, and from the illusion that morality requires cosmic surveillance. In one of the book’s most compelling threads, he suggests that recognizing our full biological reality—finite, embodied, precious—opens us to the kind of gratitude Mary Oliver captured when she asked what we would do with our “one wild and precious life.”

By the final pages, Barash has achieved something rare: a rigorous scientific argument delivered with philosophical warmth. The Soul Delusion is not a cold erasure of mystery but an invitation to see wonder in what is real and material, not what is imagined and fictional. In an age still haunted by old metaphysics, this book is a bracing, necessary reminder that life without souls may, in fact, be richer, kinder, and more deeply human: a soul-free society is a better, more mind-ful world.