David Lewis-Williams has been at the forefront of rock art research for decades now. His ideas about the origins and meanings of such art, developed in the Southern African context, have revolutionised the field, and now he has extended those insights to an examination of European prehistoric rock art as well.It’s bizarre to realise, reading the historical-overview sections of The Mind in the Cave, that rock art was once viewed as simply the interior decor of cave-people — and that for a long time there was no sense at all that this extraordinarily complex, accomplished and beautiful work was produced thousands and thousands of years ago. As bizarre, in fact, as the notion that San artists were simply illustrating their environment or behaviour and had no meaningful religion or cosmology.Drawing on anthropological accounts of San religious beliefs and practices, Lewis-Williams showed how their art is suffused with the visual phenomena experienced by shamans and others in the trance states that are a key part of their rites. In this new book, he strengthens the argument, using contemporary neuroscience and evolutionary psychology to demonstrate how such visions arise in the mind, and how a recollection of them in the waking or quotidian world gives rise to the sense of a sacred space beyond, behind or immanent in the material universe. He argues that the ability to recollect and order such visions was possessed by our ancestors the Cro-Magnons, but not by Neanderthals, who lived alongside Cro-Magnons for 10 000 years without producing such images. I could have done with a bit more palaeoanthropological and anatomical data here, but Lewis-Williams is nonetheless able to provide a convincing explanation for the sudden surge of creativity that took place in European rock art between 35 000 and 25 000 years ago.This is fascinating stuff, especially for what it says about the birth of human spirituality. Basically, as I understand it, Lewis-Williams is positing that dream and trance states, and their later recollection and ordering, produce in humans both a sense of the numinous and the beginnings of social hierarchies. In a way, the ability to negotiate between dream or trance states and the more rational mind, allowing them to give significance to each other, is one that is (in the Lacanian phrase) humanity’s “accession to the symbolic”. It was a huge conceptual leap that made new forms of consciousness possible: it increased immeasurably our capacity for meaning-creation. It gave us gods.There is much more in The Mind in the Cave, more than I can give an account of here. If the book is intended for an academic market as well as a general audience, which it appears to be, Lewis-Williams manages very ably to straddle the divide. For this general reader, with no academic background in the area (still, indeed, processing this intriguing information), it was unfailingly readable. Once past the rather dense summaries of previous theories of rock art, it was practically unputdownable.In particular, Lewis-Williams’s detailed readings of specific cave “cathedrals” are riveting. His notion of the cave wall as a kind of membrane between the material and spirit worlds almost gives one goosebumps to read. And yet a lot is still mysterious, and one wishes at moments that Lewis-Williams were prepared to go further, even if it means dropping the guard of academic propriety and entering the realm of rank speculation. His speculations are bound to be stimulating.Why, for instance, in a cave complex filled to bursting with images of herbivores, is there one “diverticule”, a concealed cul-de-sac, featuring only felines? In general, Lewis-Williams is rather sniffy about the old “sympathetic magic” interpretation of rock art — the idea that it represented the creatures prehistoric humans hunted and thus wanted in some way to attract or, having hunted them, to replenish. Maybe it also represented creatures they were trying to avoid or propitiate (or maybe different clans felt differently about different animals, as in totemistic animism). Perhaps the “magic” theory could, in a more subtly articulated form, find some points of convergence with the shamanistic idea; post-modern discourse theory might have something to offer. Even Lewis-Williams has not, I think, exhausted the possible significances of these amazing images.