It consists of some analysis, some pharmacological background, but largely case reports from a group of patients who received L-DOPA to treat a rare and intense form of Parkinson’s Disease as a result of a mysterious virus that spread through the global population at around the same time as the Great Flu Pandemic.

I’m surely not the first to be surprised, but it is not at all how you would expect a text based in neuro-psychology to unfold. Nor is the deeply philosophical Dr Sacks at all like the hard-nosed devotees of scientism that I met when working for the Psychology department at the University of Melbourne.

In fact, what Sacks details is more like a set of incredibly beautiful, illuminating and sad short stories arranged around a common theme, of disintegrated minds chaotically reintegrated in unpredictable ways.

Together, these intimate portraits coalesce to reveal some outline of the being of the mind – not purely a mechanics, and not simply the dramas of the ego. It’s a moving-picture of the mind that comes out something like an Escher sketch.

It answers any model of human consciousness and behaviour that would arrange us on a bell curve of normality. What he details is much closer to a hive, an ever twisting, changing, growing root system.

The implications of his work span from scientific psychology to metaphysical philosophy and in a most dramatic way collapse the distinctions between the two.