“The expressive difference between these face depends exclusively on a particular movement of the lower eyelid. […] The muscle that produces this texture in the lower eyelid does not obey one’s will; it can only be put into play by true affection, by an emotion that is pleasing to the soul. Its inertia, during a smile, unmasks false friends. […] Not only does it bring cheer to the eye – and in that sense, it is the counterpart to the zygomatic major, for the smile – but it also, in certain circumstances, under the influence of affectionate sentiments, contracts partially. In that case, it brings loving kindness to the gaze” (p. 62-63).