'Jacques le Fataliste et son maître' is hardly a novel. In fact, it's a very clever parody on the clichés of narration, blind faith and many other things. One should always keep in mind that this is a conceptual novel, written to challenge the standards and thoughts of 18th century France.
Jacques is marked by a form of extreme fatalism - everything that happens to him happens because it was 'meant to be so'; everything is 'written in the stars'. There is, however, no mention of a God who determines this course of events, which points towards an atheism of Diderot's part. Ironically, the figure of Jacques dominates that of his Master, who is much more passive and lacks the talktative nature of Jacques. Whereas the conversations between Jacques and his Master challenge the philosophical and social climate of the time, the narrator exposes the problems of the novel form. Diderot often underlines the fact that this book is in fact not a novel, but a truthful representation of events. Again, this is very ironic, since the narrator intrudes often and violently. The main problems are verisimilitude (how true is a story?) and the boundaries of the author (what is and isn't possible in a novel?).
The whole makes for a very fragmented book, with lots of unfinished stories and puzzling events. This does not, however, mean that the structure of the book is completely random. The chaos of events and stories hides a very clever attempt to challenge the central themes of 18th century literature, and makes this book a very unique document.