An erudite, deep-thinking writer with a varied background. As a neuropsychologist who was a monastery initiate turned atheist, Mitchell tries to describe the phenomenon of psychedelic drugs and experience from various viewpoints, including his own as he trips on various substances, including LSD, mushrooms, ayahuasca, dimethyltripamine (DMT), ibogaine, Watchuma and rappe. His descriptions are profound and philosophical, but also vivid, lively and sometimes amusing. Places stress on the use of psychedelics as a way of promoting neuroplasticity and breaking old mental habits, which are seen as “canalisation” ([P.58] “something like ‘overlearning’, referring to the limiting of one’s behavioural repertoire .. [or] as a defence mechanism against uncertainty.” Set in South America (including among the Kogi people), Silicon Valley and London, ranges from a memoir, to academic thesis, to breathless trip reportage, to philosophical musings and valuable insights. Always authentic, though a little stiff at times as the scientist edges out the tripper but always well expressed. Advises against over-exuberance in framing psychedelics as psychiatry’s “new best friend,” advocating their use in this context but cautioning about getting too starry eyed. Draws parallels between tripping and dreaming as mental processes, pointing out that just as many of our dreams are partially unpleasant, perhaps [P.51] “to support our capacity to tolerate or regulate challenging emotions”, tripping almost invariably contains unpleasant moments too. And could hearing voices, (P.217) “the iconic psychotic symptom, be a ‘signal error’, the misattribution of internal thought”? Mitchell is always reaching for new ways of thinking and this may be the greatest strength of the book. Reading it is almost like a trip in itself. There is a little bit of a lot of things in this book. For example, he questions (P.134) “the concept of addiction as an individual disease, rather than a complex social, economic and cultural phenomenon.” And in the context of “set” and “setting” as popularised by Michael Pollan, notes that (P.87) “our setting, contemporary Western society, with its various catastrophes and imagined threats, is increasingly thought of as traumatogenic.” So could, then, the contemporary idea of most of us having mental health issues (I’m not talking DSM here) be a natural response to the disordered world we live in? There are many ideas to digest in this book. Notes that pharmaceutical companies carry out “bioprospecting” (and “biopiracy”) and try to create analogues and tweaked versions of natural psychedelics they can commercialise. Mitchell’s scope is as much medical and neuroscientific as mystical and philosophical.