Colin Wilson's prolific trek from his debut with The Outsider, through his less academically respectable and increasingly esoteric forays into the occult or his explorations of the criminal mind, seems to lead inexorably towards the application of his patented anecdotal, critical approach to this murkily contentious area.

The sunken continent of Atlantis was teasingly posed by Plato in 350 BC, and has had regular cycles of vogue ever since. Jules Verne's Captain Nemo and Conan Doyle's Professor Challenger both discovered it intact on the floor of the Atlantic Ocean. Pulp sf writer John Russell Fearn even located them on Jupiter's Great Red Spot. Around the same time (the late 1940s), drawing on the cod mysticism of Madame Blavatsky's school of artful Theosophist fakery, Amazing Stories carried a controversial series of 'Shaver Mysteries', which claimed to be based on thought-records emanating from surviving, subterranean Atlantean technology. More factoid commentary shifted the hypothetical locations of the sunken continent from Bermuda to the Canary Islands, then back into the Mediterranean to Santorini.

Wilson has no truck with such trivia. What emerges most strongly, even if you discount his more extreme conclusions, is that the ancient world is very imperfectly understood, less so by far than Academia would have us believe. This neatly ties in with recently televised Egyptological in-fighting about the age of the Sphinx, which appears to bear traces of water erosion and must hence be far older than the textbooks say. Even the exact succession of Pharaohs, cross-referenced from Pyramid inscriptions to supposedly concurrent Hebrew texts throws up puzzling inconsistencies. Wilson is quick to scorn (and by doing, distance himself from) Erich von Daniken's once hugely popular 'Was God an astronaut?' books of the mid seventies. Von Daniken falsified evidence and selectively misrepresented his 'facts'. It's by no means necessary, says Wilson, to impose extraterrestrial interference on human evolution. Early humans were simply smarter than we give them credit for, and if there was a proto-civilisation of which no records or remains exist, a culture that flourished and then vanished before the dawn of conventional history, one that passed fragments of its knowledge to ignite Sumer, Egypt, and the Indus cities of Mohenji-Daro, then we might as well, for the sake of argument, call it Atlantis. Ignatius Donnelly suggested as much in 1882.

The possibilities are obvious. Modern humans emerged during the Pleistocene era, the period of the ice ages. With the end of glaciation came rising sea levels and land inundation; hence, conceivably, the race memory of sunken lands, not only Atlantis but Lemuria and Lyonesse too. Glaciation also created drastic shifts in habitable temperate zones -- the Sahara was once forested. So much is fact, though the exact mechanics of ice age phenomena are poorly understood; there's evidence of partial glaciation more complex than current models allow for. Perhaps there was a tilt in the Earth's axis which had the effect of nudging the Northern polar regions downwards across Europe? The same process would relocate the South Pole somewhere over the Pacific and free Antarctica of ice. Throw in a little continental drift and some plate tectonics, and something very like an 'Atlantis' emerges.

Too fanciful? It's not necessary to impose ET interference on human evolution, but some of the awkward squad of inexplicable artefacts are worth recycling here, the 16th century Piri Re'is maps, for example. Used by Turkish navigators, copied from earlier originals, they appear not only to show the then undiscovered coastline of Antarctica, but to show it in a pre-glacial state. Von Daniken saw this as evidence of ancient spaceship surveys; to Wilson, it just might betray the location of Atlantis. There is, of course, much more, tapping into sources of huge diversity. Among other things, Wilson draws extensively on Egyptology through lenses provided by Graham Hancock's Fingerprints of the Gods and others.

In some ways the Atlantis tag is an intellectual flag of convenience. What unifies Wilson's work is his preoccupation with intelligence; its origins and development, its uniqueness and deviance and, most importantly, its potential. What's important is not what pre-ice age cultures were called, or whether they existed in what is now the Sahara or Antarctica, but how they thought. How they perceived the universe and their role in it, and how that world view differs from our own. At one point in the evolution of consciousness a decisive split occurred, from the 'right brain' intuitive, tribal-collective kind of animalistic perception, to the 'left brain' analytical, individualistic mindset which enables the invention of TV, modern plumbing, and books like this to exist. Atlantis exists in the time before this shift. Wilson conjectures some kind of hierarchical-mystic, social structure based around Shamanic Priest-Kings 'in tune' with their environment in ways it's no longer possible for us to understand, never mind experience. Something like Altered States, only more so; a state far from the Utopian ideal described by Plato or allegorised by Francis Bacon yet, implies Wilson, there's something we can salvage here.

It could be argued that we've spent 10,000 years growing out of that, that sub-atomic quarks, relativistic Big Bang astrophysics, even the computer Wilson's book was no doubt written on are convincing arguments for the superiority of our kind of boringly lateral thinking. Or perhaps not.