In an an­im­ated con­ver­sa­tion, I of­ten see the face of the per­son with whom I am speak­ing so clearly and sharply defined be­fore me, ac­cord­ing to the thought he ex­presses, or which I be­lieve to be evoked in his mind, that the de­gree of dis­tinct­ness far ex­ceeds the strength of my visual fac­ulty—the del­ic­acy of the play of the muscles and of the ex­pres­sion of the eyes must there­fore be ima­gined by me. Prob­ably the per­son put on quite a dif­fer­ent ex­pres­sion, or none at all.