First published in 1954, it details his experiences when taking mescaline. The book takes the form of Huxley's recollection of a mescaline trip that took place over the course of an afternoon in May 1953. The book takes its title from a phrase in William Blake's 1793 poem 'The Marriage of Heaven and Hell'. Huxley recalls the insights he experienced, which range from the "purely aesthetic" to "sacramental vision". He also incorporates later reflections on the experience and its meaning for art and religion.

    On his travels he ponders Thoreau's eager seclusion in Walden Woods; the reason Rimbaud walked in a fury, while Nerval rambled to cure his melancholy. He shows us how Rousseau walked in order to think, while Nietzsche wandered the mountainside to write. In contrast, Kant marched through his hometown every day, exactly at the same hour, to escape the compulsion of thought. Brilliant and erudite, A Philosophy of Walking is an entertaining and insightful manifesto for putting one foot in front of the other.