There is a psychedelic revolution happening. An increasing number of studies are promising a transformation of mental health through their controlled use. What is still unclear is what exactly the nature of that psychedelic experience is, and what makes it so powerful. Sceptics are too quick to dismiss the whole thing as a hallucination, merely a disturbance of the brain’s chemistry. But a closer look at the philosophy of consciousness seems to suggest otherwise, writes Ricky Williamson.

I am currently sitting in an airport on an 8-hour lay-over. The next plane was just cancelled, adding an extra 4-hour delay. A pretty good metaphor for base reality. Is it possible to experience another world? Something transcendent? Is it possible to experience something outside normal human experience? Will I ever get on the plane?