At that time, he and his supporters established the Université populaire de Caen, proclaiming its foundation on a free-of-charge basis and on the manifesto written by Onfray in 2004 (La communauté philosophique).

Based on Onfray's book La Communauté philosophique: Manifeste pour l'Université populaire (2004), the original UP now has imitators in Picardy, Arras, Lyon, Narbonne, and Le Mans, with five more in preparation.

Approaching philosophy as a reflection of each individual's personal experience, Onfray inquires into the capabilities of the body and its senses and calls on us to celebrate them through music, painting, and fine cuisine.

"[19] "Onfray's philosophical project is to define an ethical hedonism, a joyous utilitarianism, and a generalized aesthetic of sensual materialism that explores how to use the brain's and the body's capacities to their fullest extent – while restoring philosophy to a useful role in art, politics, and everyday life and decisions.

"[12] Onfray's works "have explored the philosophical resonances and components of (and challenges to) science, painting, gastronomy, sex and sensuality, bioethics, wine, and writing.

Onfray writes: In opposition to the ascetic ideal advocated by the dominant school of thought, hedonism suggests identifying the highest good with your own pleasure and that of others; the one must never be indulged at the expense of sacrificing the other.

"[20] In La puissance d'exister: Manifeste hédoniste, Onfray claims that the political dimension of hedonism runs from Epicurus to John Stuart Mill to Jeremy Bentham and Claude Adrien Helvétius.

He names also the "alcoholic philosophers": Friedrich Nietzsche, Jean-Paul Sartre, Simone de Beauvoir, Gilles Deleuze, Guy Debord and Raoul Vaneigem, in particular, to whom he dedicated his Traité d'athéologie (2005).

[22] In Atheist Manifesto, Onfray states that among the "incalculable number of contradictions and improbabilities in the body of the text of the synoptic Gospels"[23] two claims are made: crucifixion victims were not laid to rest in tombs, and in any case, Jews were not crucified in this period.

The historian John Dickson, of Macquarie University, has said that Philo of Alexandria, who wrote about the time of Jesus, noted that the Romans sometimes handed the bodies of crucifixion victims over to family members for proper burial.

[26] In July 2021, Onfray criticised Pope Francis's apostolic letter Traditionis custodes by arguing that the Tridentine Mass embodies “the heritage of the genealogical time of our civilization".

That is particularly the case of the historians Guillaume Mazeau, Élisabeth Roudinesco, Jean-Marie Salamito with his essay Monsieur Onfray au pays des mythes as well as Ian Birchall.