stage with all the nobility and simplicity of adjustment that her characters demand; nay, in the disorder into which she would be thrown by an event so terrible as the death of a husband, the loss of a son, and the other catastrophes of the tragic stage, what would become, round her dishevelled figure, of all those powdered, curled, frizzled, tricked-out creatures?  Sooner or later they must put themselves in unison.  O nature, nature!  We can never resist her."[285]

From all this we turn, for a few moments only, and not too cheerfully, to the Serbonian bog of dramatic rules and the metaphysics of the theatre.  There is no subject in literature, not even the interpretation of the Apocalypse, which has given birth to such pedantic, dismal, and futile discussion.  The immense controversy, carried on in books, pamphlets, sheets and flying articles, mostly German, as to what it was that Aristotle really meant by the famous words in the sixth chapter of the Poetics, about tragedy accomplishing the purification of our moods of pity and sympathetic fear, is one of the disgraces of human intelligence, a grotesque monument of sterility.  The great tap-root of fallacy has been and remains the incessant imputation of ethical or social purpose to the dramatist, and the demand of direct and combined ethical or social effect from the drama.  There is no critic, from the great Aristotle downwards, who has steered quite clear of these evil shallows; Diderot, as we have seen, least of all.  But Diderot disarms the impatience which narrower critics kindle, by this magnificent concession, coming at the close of all:  “Especially remember that there is no general principle; I do not know a single one of those that I have indicated which a man of genius cannot infringe with success."[286] Here we listen to the voice of the genuine Diderot; and if this be granted, we need not give more than a passing attention to the rules that have gone before—­about the danger of borrowing in the same composition the shades both of the comic and of the tragic styles; about movement being injurious to dignity, and of the importance therefore of not making the principal personage the machinist of the piece; about the inexpediency of episodic personages—­and so forth.  The only remark worth making on these propositions is that, whatever their value may be, Diderot at any rate, like a true philosopher, generalised from the facts of nature and art.  He did not follow the too common critical method of reading one’s own ideas into a work of art, and then taking them back again in the more imposing form of inevitable deductions from the work itself.