Gratiolet, in his treatise on physiognomy, groups under this term all the modifications of form, of colour, etc, which manifest themselves on the surface of the body, under the influence of the most widely different causes. These movements are direct, sympathetic, or symbolic.

In looking at an object, the action of the eyes, and the animation which they give to the expression, are direct movements; but if we fix the attention, the body takes part in the action of the eyes, inclines forward, and seems to wish to move toward the object observed; these are sympathetic movements, and when thinking of extreme cold we shiver, this is a symbolic movement.

The limbs, the trunk, and the head, that is to say, the gestures and attitude, contribute greatly to complete the physiognomy, as has already been remarked; the cavities, on the contrary, take no part in it, the seat of expression is in the skin, the muscles, and the eyes.