He enters very little into theoretical considerations, and seldom attempts to explain why certain muscles and not others contract under the influence of certain emotions. A distinguished French anatomist, Pierre Gratiolet, gave a course of lectures on Expression at the Sorbonne, and his notes were published (1865) after his death, under the title of `De la Physionomie et des Mouvements d'Expression.' This is a very interesting work, full of valuable observations. His theory is rather complex, and, as far as it can be given in a single sentence (p. 65), is as follows:--"Il resulte, de tous les faits que j'ai rappeles, que les sens, l'imagination et la pensee ellememe, si elevee, si abstraite qu'on la suppose, ne peuvent s'exercer sans eveiller un sentiment correlatif, et que ce sentiment se traduit directement, sympathiquement, symboliquement ou metaphoriquement, dans toutes les spheres des organs exterieurs, qui la racontent tous, suivant leur mode d'action propre, comme si chacun d'eux avait ete directement affecte."
 `Handbuch der Systematischen Anatomie des Menschen.' Band I. Dritte Abtheilung, 1858.
Gratiolet appears to overlook inherited habit, and even to some extent habit in the individual; and therefore he fails, as it seems to me, to give the right explanation, or any explanation at all, of many gestures and expressions. As an illustration of what he calls symbolic movements, I will quote his remarks (p. 37), taken from M. Chevreul, on a man playing at billiards. "Si une bille devie legerement de la direction que le joueur pretend zlui imprimer, ne l'avez-vous pas vu cent fois la pousser du regard, de la tete et meme des epaules, comme si ces mouvements, purement symboliques, pouvaient rectifier son trajet? Des mouvements non moins significatifs se produisent quand la bille manque d'une impulsion suffisante. Et cliez les joueurs novices, ils sont quelquefois accuses au point d'eveiller le sourire sur les levres des spectateurs." Such movements, as it appeirs to me, may be attributed simply to habit. As often as a man has wished to move an object to one side, he has always pushed it to that side when forwards, he has pushed it forwards; and if he has wished to arrest it, he has pulled backwards. Therefore, when a man sees his ball travelling in a wrong direction, and he intensely wishes it to go in another direction, he cannot avoid, from long habit, unconsciously performing movements which in other cases he has found effectual.
As an instance of sympathetic movements Gratiolet gives (p. 212) the following case:--"un jeune chien A oreilles droites, auquel son maitre presente de loin quelque viande appetissante, fixe avec ardeur ses yeux sur cet objet dont il suit tous les mouvements, et pendant que les yeux regardent, les deux oreilles se portent en avant comme si cet objet pouvait etre entendu." Here, instead of speaking of sympathy between the ears and eyes, it appears to me more simple to believe, that as dogs during many generations have, whilst intently looking at any object, pricked their ears in order to perceive any sound; and conversely have looked intently in the direction of a sound to which they may have listened, the movements of these organs have become firmly associated together through long-continued habit.
Dr. Piderit published in 1859 an essay on Expression, which I have not seen, but in which, as he states, he forestalled Gratiolet in many of his views. In 1867 he published his `Wissenschaftliches System der Mimik und Physiognomik.' It is hardly possible to give in a few sentences a fair notion of his views; perhaps the two following sentences will tell as much as can be briefly told: "the muscular movements of expression are in part related to imaginary objects, and in part to imaginary sensorial impressions. In this proposition lies the key to the comprehension of all expressive muscular movements." (s. 25) Again, "Expressive movements manifest themselves chiefly in the numerous and mobile muscles of the face, partly because the nerves by which they are set into motion originate in the most immediate vicinity of the mind-organ, but partly also because these muscles serve to support the organs of sense."