The same features mark his plays, though here the result has ceased to be pleasing, and we may be permitted to-day not to read through the “Fils Naturel” and the “Père de Famille.” Yet we must not forget that from them is dated the modern drama, with the notes of sincerity and simple realism, peculiar then to Diderot, which nowadays have become a more common possession. Diderot’s dramas produced a great and immediate effect in Germany, on Goethe and Schiller as well as on Iffland and Kotzebue, and the “Père de Famille” was translated by Lessing.
As a critic of the stage Diderot has, perhaps, attracted exaggerated attention, though he has not escaped misunderstanding, most people’s knowledge of his opinions on this head beginning and ending with the “Paradoxe sur le Comédien.” Diderot at first attributed, as from the nature of his temperament he was sure to do, the chief part in acting to emotion and sensibility; in time he outgrew this youthful opinion, and in the “Paradoxe” he emphasized as strongly as he could the part of study and reflection in the actor’s art, a part which must always be of the first importance, notwithstanding all the tears shed by charming actresses, and carefully bottled for controversial purposes. Diderot was far too sane and many-sided to see only one aspect of so complex an art as the actor’s; it is, as he says, “study, reflection, passion, sensibility, the true imitation of nature,” which go to make up good acting. An interesting and too brief series of letters to Mlle. Jodin is well worth reading from this point of view. Mlle. Jodin, the daughter of an old friend of his, was a rather wild and impetuous young lady of some talent who had suddenly adopted the life of an actress. Diderot performed many small services both for her and her mother, and wrote letters full of wise and, it appears, much-needed counsel as to her conduct both on and off the stage. “Mademoiselle,” he writes, “there is nothing good in this world but that which is true; be true, then, on the stage, true off the stage.... An actor who has nothing but sense and judgment is cold; one who has nothing but _verve_ and sensibility is mad. It is a certain temperament of mingled good sense and warmth which makes men sublime; on the stage and in the world he who shows more than he feels makes us laugh instead of touching us.”