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.

    Two years later, his predictions were borne out by the rise to power of a series of political outsiders whose economic nationalism and authoritarian tendencies threatened to destabilize the entire international order. These populist nationalists seek direct charismatic connection to "the people," who are usually defined in narrow identity terms that offer an irresistible call to an in-group and exclude large parts of the population as a whole.Demand for recognition of one's identity is a master concept that unifies much of what is going on in world politics today. The universal recognition on which liberal democracy is based has been increasingly challenged by narrower forms of recognition based on nation, religion, sect, race, ethnicity, or gender, which have resulted in anti-immigrant populism, the upsurge of politicized Islam, the fractious "identity liberalism" of college campuses, and the emergence of white nationalism. Populist nationalism, said to be rooted in economic motivation, actually springs from the demand for recognition and therefore cannot simply be satisfied by economic means. The demand for identity cannot be transcended; we must begin to shape identity in a way that supports rather than undermines democracy.Identity is an urgent and necessary book--a sharp warning that unless we forge a universal understanding of human dignity, we will doom ourselves to continuing conflict.