certainly, and almost certainly to his damage. _Le Neveu de Rameau_ is imperative: nay, the much-abused _Jacques le Fataliste_ itself must not be neglected.[162] [Sidenote: _But hardly to be exaggerated. His Impressionism._] Diderot is the first considerable critic—it would hardly be too much to say the first critic—known to history who submits himself to any, to every work of art which attracts his attention, as if he were a “sensitised” plate, animated, conscious, possessing powers of development and variation, but absolutely faithful to the impression produced. To say that he has no theories may seem to those who know him a little, but only a little, the very reverse of the truth: for from some points of view he is certainly a _machine à théories_ as much as Piron was a _machine à saillies_. But then the theory is never a theory _precedent_; it never (or so seldom as to require no correction of these general statements) governs, still less originates, his impression; it follows the impression itself and is based thereon. Not seldom the substructure, if not even the foundation, of the impression itself may seem to us quite disproportionate to the originating work of art—be it book, or play, or picture; but that is not the point. Constantly, the enthusiasm which had made Diderot give himself up to the fascination of his new subject may seem to lead him into all sorts of extravagances. The best known and perhaps the best example of these extravagances, the almost famous _éloge_ of Richardson, has been drawn upon by nearly everybody who has written on Diderot, and by most who have written on Richardson, for examples. [Sidenote: _The Richardson éloge._]