Adam Gopnik at The New Yorker:
Diderot is known to the casual reader chiefly as an editor of the Encyclopédie—it had no other name, for there was no other encyclopédie. Since the Encyclopédie was a massive compendium of knowledge of all kinds, organizing the entirety of human thought, Diderot persists vaguely in memory as a type of Enlightenment superman, the big bore with a big book. Yet in these two new works of biography he turns out to be not a severe rationalist, overseeing a totalitarianism of thought, but an inspired and lovable amateur, with an opinion on every subject and an appetite for every occasion.
He was and remains, as Zaretsky says simply, a mensch. He is also a very French mensch. He is a touchingly perfect representative—far more than the prickly Voltaire—of a certain French intellectual kind not entirely vanished: ambitious, ironic, obsessed with sex to a hair-raising degree (he wrote a whole novella devoted to the secret testimony of women’s genitalia), while gentle and loving in his many and varied amorous connections; possessed of a taste for sonorous moralizing abstraction on the page and an easy temporizing feel for worldly realism in life; and ferociously aggressive in literary assault while insanely thin-skinned in reaction, littering long stretches of skillful social equivocation with short bursts of astonishing courage.