These digressions are one source of the charm of Diderot's criticism. They impart ease and naturalness to it, because they evidently reproduce the free movement of his mind as it really was, and not as the supposed dignity of authorship might require him to pretend. There is no stiffness nor sense, as we have said, of literary strain, and yet there is no disturbing excess of what is random, broken, _decousu_. The digression flows with lively continuity from the main stream and back again into it, leaving some cheerful impression or curious suggestion behind it. Something, we cannot tell what, draws him off to wonder whether there is not as much verve in the first scene of Terence and in the Antinoues as in any scene of Moliere or any work of Michael Angelo? "I once answered this question, but rather too lightly. Every moment I am apt to make a mistake, because language does not furnish me with the right expression for the truth at the moment. I abandon a thesis for lack of words that shall supply my reasons. I have one thing in the bottom of my heart, and I find myself saying another. There is the advantage of living in retirement and solitude. There a man speaks, asks himself questions, listens to himself, and listens in silence. His secret sensation develops itself little by little." Then when he is about to speak of one of Greuze's pictures, he bethinks himself of Greuze's vanity, and this leads him to a vein of reflection which it is good for all critics, whether public or private, to hold fast in their minds. "If you take away Greuze's vanity, you will take away his verve, you will extinguish his fire, his genius will undergo an eclipse. _Nos qualites tiennent de pres a nos defauts._" And of this important truth, the base of wise tolerance, there follow a dozen graphic examples.[47] [47] x. 342. He says elsewhere of Greuze (xviii. 247) that he is _un excellent artiste, mais une bien mauvaise tete_.