After spending five years as a young man studying philosophy and theology at the Paris Sorbonne (1730–35), Denis Diderot earned his living in Paris as a tutor, immersed in the French clandestine philosophical literature, soon becoming a subversive philosophe himself. First, he adopted a deist stance in his Pensées philosophiques (1746), but soon rejected deism. Knowing his second foray, the Promenade du sceptique, written in 1747, would be totally unacceptable to the authorities, he left it unpublished. Though printed only long after his death (1830), it remains a key to his early intellectual development, relating an idealized debate between a group of philosophers all disagreeing but all also rejecting revealed religion – a deist, sceptic, spinoziste, and representative of a crudely mechanistic, Epicurean atheism reminiscent of La Mettrie. Finally, it is the spinoziste who triumphs by presenting the most cogent, compelling, and morally most uplifting stance, an important indication of Diderot’s own lasting commitment to a creed he calls that of the “Spinosistes modernes.”