Few ideas are as unsupported, ridiculous and even downright harmful as that of the ‘human soul’. And yet, few ideas are as widespread and as deeply held. What gives? Why has such a bad idea had such a tenacious hold on so many people? Although there is a large literature on the costs and benefits – psychological and economic – of traditional religion, there is a dearth of comparable research on religion’s near-universal handmaiden, the soul. As with Justice Potter Stewart’s non-definition of pornography – ‘I may not be able to define it, but I know it when I see it’ – the soul is slippery and, even though it cannot be seen (or smelled, touched, heard or tasted), soul-certain people seem to agree that they know it when they imagine it. And they imagine it in everyone.
Viewed historically and cross-culturally, there is immense variation regarding the soul, although some patterns can be discerned and are nearly universal. Souls are said to reside inside their associated bodies and are pretty much defined as immaterial, thereby contrasted with their fleshy habitations. Immortality is another close, but not quite universal, characteristic. Also widespread, but not invariant, is the soul’s ability to travel independent of its body, sometimes after death but often during sleep. Dreams are widely seen as demonstrating not only that the soul is ‘real’, but that it occupies its own unique plane of reality.
Jewish doctrine says almost nothing about the soul. ‘[T]here is no way on earth,’ wrote the influential Jewish philosopher Moses Maimonides, ‘that we can comprehend or know it.’ This agnostic attitude is consistent with Judaism’s lack of specificity regarding the afterlife generally and of heaven and hell in particular. By contrast, Christianity and Islam are clear when it comes to the soul, conceiving it as immaterial as well as immortal, the two perspectives being, as it were, soulmates. Although Islam has a variety of views when it comes to the soul, there is greater diversity within Christianity – between Protestant, Catholic, and Orthodox conceptions – and also within Protestantism, ranging from evangelical fundamentalism to the more relaxed and philosophical approaches of modern-day Quakers and Unitarians.
The Hindu soul resembles its Abrahamic counterpart with regard to immateriality and immortality, but with two major differences. For one, the soul (atman, or ‘self’) is conceived as a personalised part of a greater world-soul (brahman, closer to the Western ‘God’). Second, the Hindu soul is subject to regular reincarnations following the death of its body, including excursions into different kinds of animals, depending on its accumulated karma. The final desired destination of this process of repetitive birth and rebirth – oversimplified as nirvana – somewhat resembles the Western concept of heaven, although it is conceived more as a respite from the cycle of birth and rebirth than as an abode of ongoing bliss.
When trekking in the Himalayas, I often followed the sherpa advice that one should pause every third day, ‘to let your soul catch up with your body.’ It made a kind of intuitive sense. One needn’t be a Buddhist or travelling at extreme elevation to appreciate this wisdom. As a metaphor for mind, consciousness, one’s deeper beliefs and desires, the soul is serviceable. But its appeal goes beyond linguistic or conceptual utility.

Whatever else the soul is supposed to be, it is immaterial: ie, lacking physical substance. That doesn’t necessarily mean it doesn’t exist, because other ‘things’ without structural reality are real as immaterial concepts: love, fear, hope, and so forth. Some things exist only as genuine objects, rather than in the realm of the ideal or the conceptual: chairs, fire hydrants, trombones. There is no reason to discount the soul simply because there is no universally accepted sense of what it is. Just as one person’s terrorist is another’s freedom fighter, one person’s conception of the soul as possessing a spark of the divinely supernatural may be another’s mind, free will, conscience, and so forth.
But no one claims that personal memories or the Pythagorean theorem are imbued with a God-given spark, or that they exist in the sense that they can be bartered and commodified like the soul, which can by some accounts be sold to the devil (suggesting that it is at least somewhat concrete). Nor are immaterial concepts supposed to reside within each person, to disappear – and then re-emerge elsewhere – after the death of the body. Soul-zealots do not accept that it exists only in a hazy, ectoplasmic plane: our unique dose of fairy dust. It is purportedly real, albeit not quite like the body in which it resides.
Immateriality – especially when blindly accepted but not seriously interrogated – is useful to the soul’s mythology, because failure to see, hear, smell, touch or taste that which is immaterial isn’t a dispositive argument against it. For believers, the fact that the soul cannot be perceived by the senses becomes an argument for its superiority, because it doesn’t partake of the messiness and dross of our everyday, fallen world. That is one of the soul’s great attractions.
Modern science hasn’t yet come up with an alternative answer to what, precisely, makes something alive
It is also deeply flattering to be told that part of oneself is a chip off the old divine block, all the more so given that the devil is desperate to get it from you, while religion – acting as God’s representative – is equally eager to save it for you. How empowering to be told that we possess something uniquely our own and, moreover, that it is of inestimable value, no matter one’s station in life. Like the Colt-45 in the Wild West, souls are great equalisers. At the same time, souls are paradoxically delicate and must be guarded like a Victorian maiden’s virginity, lest it be lost and you ruined – not merely excluded from a secular marriage market, but consigned to ruination that is potentially eternal, deprived of union with God and, in the worst case, consigned to eternal torment.
The soul’s alleged immateriality offers yet more psychological appeal. For one thing, the difference between alive and dead is profound. The eyes are bright and busy, then dull and unresponsive. Movement occurs, then ceases. No wonder life itself has long been associated with a kind of magic substance: now you’ve got it, now you don’t. And, when you don’t, it’s because your life-force, yo