On Drugs: Psychedelics, Philosophy, and the Nature of Reality

by Justin Smith-Ruiu

A renowned philosopher takes a clear-eyed look at the mind-expanding potential and mind-blowing implications of psychedelic experiences.


In the wake of a personal loss and the global upheaval of the pandemic, philosopher Justin Smith-Ruiu found himself at a California cannabis dispensary, pondering a simple yet profound Who am I, and how did I get here? This moment marked the beginning of a transformative journey for Smith-Ruiu, one that would take him deep into the realm of psychedelics and alter his perception of the world.


On Drugs blends memoir, investigative reporting, and philosophical inquiry as Smith-Ruiu explores the profound impact of psychedelics on the mind and human consciousness. Drawing on a broad range of intellectual history and his personal experiences as “an articulate guinea pig,” he delves into how these substances challenge Western assumptions about reality, the self, and existence. By confronting the essence of our thoughts and perceptions, psychedelics offer a path to a radically new way of thinking and a new philosophical lens that could reshape how we understand ourselves and our place in the universe.


For anyone interested in philosophy, consciousness, or the transformative potential of psychedelics, On Drugs offers an insightful and thought-provoking exploration of mind-altering substances, their impact on modern thought, and the very nature of reality.

Genres: Philosophy, Nonfiction, Science

288 pages, Hardcover

Published September 23, 2025

About the author

Also writes as Justin E. H. Smith.

Reviews

[Mary Holt-Wilson · Rating 3 out of 5]

I'm not sure I learned much more than I already knew about any of the titular items, but I still found this an interesting read.

[Ben Gilbey · Rating 2 out of 5]

I was expecting something else I think.

With the title of this book, I was hoping to find a dense, detailed examination of psychedelic experiences and some of the possible philosophical implications of such experiences. This is on offer, but in a much more superficial form that I had hoped for. For example, Smith-Ruiu touches on psychedelic experiences in relation to Phenmonenology, and just begins to think about such experiences in Phenmenological terms, but then moves on, and it feels very half-baked. This is partly because this book is much more memoir than I had assumed it would be. As such I would suggest it is not really a philosophical work. It does not feel particularly rigorous or though through. Another disappointing example is when Smith-Ruiu mentions Deleuze and Guttari's works. Some of their ideas are glanced over and I would argue misrepresented, and any exploration of their thought in relation to psychdelic experience is pretty much absent.

If you have never read any work on psychdelics before, and are curious about the potential personal implications of psychedelics for yourself, and want to read about someone elses experiences and the implications it had for them, then maybe this would be a worthwhile read. It might spark a deeper curiosity to look further into psychedelics and their philosophical implications for yourself.

However, I would definitely frame this authors conclusions about psychdelics as secondary to his own personal process, which this book is clearly more focused on than on any attempt to be philosophically rigorous, critical, and objective about the complex reality of psychedelics and how they affect our experience of ourselves and reality itself.

Smith-Ruiu tells us how psychedelics ultimately brought him back to church, and reconnected him to memories of his childhood in the church. I love that for him, it's genuinely moving. But in the process, it feels like rigorous and interesting philosophical inquiry went out the window. This could have led to a fascinating reflection on what psychedelics evoke for us, and again, Smith-Ruiu sort of takes us down that road, but its more about his own personal experience than an attempt at rigorous, critical philosophical thought.

So, if you want a memoir thats laced with a smattering of philosophy, history, and some drugs, this is for you. But don't let the title decieve you, its not that interesting philosophically speaking.

[Charles Rizzo · Rating 2 out of 5]

I purchased this book after reading the New York Times review.

Although Justin's personal story is interesting i find it falls short of any real discovery. It seems as though he was in search of a common truth and at least for now has ended where he began. He argues that the inspiration of the "search for truth" that guided many of the past luminaries is supported by some type of chemistry; this seems to be his way of justifying his experimentation with psychedelics. I can understand his reasoning since i personally have experiment with LSD many time in the past and found wonder in those hours but like Justin it soon faded. It can open the doors to some new and transformative perception but it only can open the door, it wont let you in.
In William James's "Varieties of Religious Experience" he writes about his own use of chemistry to find truth and shares its short comings in his search; he understood that the door existed but he could not enter.

The mystery of transcendency has been written about through many voices over the ages and i have never personally read about psychedelics or other chemicals that assisted in these transformations. It is a gift that appears to some for whatever divine intervention and it is not connected to drugs or religion. A very best example of this is Dante's journey in the "Divine Comedy" in which man finds his destiny as he releases all of his vices to find Paradiso.

I wish Justin well but i know his journey is far from over.

[Sam · Rating 1 out of 5]

I once had a boss that was impressively intelligent but spoke in such a way that everyone else struggled to understand him. He didn't use obscure vocabulary, it was that he strung medium-length words together in unusual, exhausting ways. It reminded me of my mission, when an Armenian guy was using a bunch of slang (imagine a non-native English speaker hearing "that was mid, it’s giving type wild 6–7, bro thought he was him… yeah, we’re cooked, chat") and asked me if I understood, and I said "I understand, but I don't get it (հասկացա, բայց չջոգեցի)". It was mentally exhausting to sift through words I knew without being able to grasp their meaning.

This author and that boss would get along so well. I read a couple sentences to Kelsie – one with 6 commas – and she said it sounded like Joey from Friends running every word in his letter through a thesaurus (this is no time for dinosaurs, Ross!).

I've made it through some challenging books, but on subjects that deserve that density: fossils, quantum physics, and Russian philosophy. I did not expect a book about psychedelic drugs to take the cake! These drugs supposedly open your eyes to the world around you but this book only helped me get some extra shut-eye.

Fascinating topic, insufferable writing. DNF at 25%.

[Kara Froese · Rating 2 out of 5]

As a recently deconverted Christian, and someone curious about different world experiences (including a curiosity about psychedelics) I was excited to read this book. Imagine my disappointment upon finding out 95% of the way through that the author recently became a devout Catholic and that this clearly drastically shapes his conclusions about psychedelics and how people should use them. He even argues that a trip is the same as a religious experience. As an ex-Christian, I have a lot of thoughts on that, but don't care that much to refute his claim.

Dare I say that philosophy in general interests me very little? I'm not convinced that it's anything but a bunch of dudes who have an elevated sense of importance of their own ideas of the world (and think that there can be a right or wrong way of thinking). So I guess maybe this book wasn't written for an audience like me, and much of it probably went over my head.

[Richard Thompson · Rating 4 out of 5]

It's an interesting effort - Looking at psychedelic drugs from a philosophical perspective. What does the psychedelic experience tell us about the mind body problem, the truth or falsity of sense impressions, and our understanding of the world? Does a philosophical perspective on psychedelics give new insights into epistemology and ontology? There's a definite connection that is worth exploring, and the book makes some good initial steps in that direction. You don't need a degree in philosophy (nor do you need to have taken psychedelics yourself) to understand the discussion. Still, I came away from the book feeling that there are further depths to be plumbed both on the drug side and on the philosophy side, though that may be hard to do since most drug people don't care about philosophy, and most philosophers turn up their nose at psychedelic drugs as a vehicle for doing philosophy.

[Kathy · Rating 3 out of 5]

I finished it. That counts for something. This vacillates between philosophical treatise and memoir. The descriptions of what it’s like to be on psychedelic drugs were bizarre and sort of comical. He made some interesting points that I couldn’t regurgitate back. I was disappointed by the conversion to Catholicism.

[Mindaugas Genutis · Rating 1 out of 5]

It’s a rather shallow take on a fascinating topic. Instead of exploring it in depth, the author chose to provide a superficial overview of what’s already known. A book like this could easily have been written by AI, it shows little evidence of genuine investigation or original research.

[Maddy Walock · Rating 3 out of 5]

I feel like there were interesting points and stories but altogether I didn’t find this book teaching me much nor giving deep insight. Still interested in the topic, I want to read more literature like this.

[Rick · Rating 2 out of 5]

Like an Erowid trip report that meanders into a random assortment half-digested history and philosophy works. Despite copious self-revelations, Smith-Ruiu denies that this is a memoir. If it had been, it might have been much better (and more focused) than whatever this is.

[Calvin Baker · Rating 2 out of 5]

Pace the author, this book did not seem to me to raise any interesting, substantive philosophical questions. My main takeaway is that doing psychs can shift your priors around by making certain (wacky, minority) philosophical positions like theism and panpsychism appear more plausible to you.

[AMAO · Rating 5 out of 5]

📚📚📚📚📚

[Jim Parker · Rating 5 out of 5]

Certainly much food for thought. Full of quotable material. I suspect almost no one will agree with everything the author presents and some may even agree with nothing. I think most people will some material with which they agree.