This influence of the expression on the mind is an extremely important element in psychotherapy. Men and women must be taught to shake off inner sadness, and over-occupation of mind, by training their facial muscles of expression as far as possible to occupy positions expressive of good feeling, but above all not to let them be fixed in positions indicative of ill feeling. It makes a great difference for the mental state whether a man has the corners of his mouth drawn down or up, or whether they are pulled straight across the face to give the severe, austere expression that some people seem to cultivate. If the corners of the mouth are allowed to droop the glumness and depression is likely to grow deeper. If the lips are curled upward and smile, even though it may be a forced smile, the inner feeling will soon yield to it. Actors are able to counterfeit the reality, but much more than this, as we have said, they realize that, by imitating the externals of the feeling, they awaken the feeling itself within them. This is true for anger and loathing, and for many of the more serious dispositions as well as for those that might be thought more superficial, and hence more controlled by the external muscles. {102} _The Mouth_.--It is interesting to realize how different are the expressions of the face as a consequence merely of control of the sphincter of the mouth and its associated muscles. Physiological psychologists have often called attention to the fact that only a few lines are necessary to picture the characteristic human expressions of sadness, joy and severity. If a little droop is given to the line that represents the lips, melancholy is at once expressed, while the upward curve expresses joy, and the straight line severity. These types of human expression are easy to control, and the internal effect of each is soon felt where there is deliberate, or indeliberate, perseverance in its maintenance. [Illustration: Fig. 1. Three abstract faces.] _The Eyes_.--A typical example of the influence of the mind on the body is to be found in the use of the eye muscles, especially the oblique muscles. Of definite and important use for many purposes, they are especially employed to attract attention by means of the eyes. Coquetry has used them to express various phases of sex attraction. We all know the picture of the young woman who "makes eyes." It is interesting, however, to set solemn people imitating these exercises of the oblique eye muscles. For most people it is practically impossible to use these muscles without a corresponding quasi-demure setting of the features, commonly associated with those who use them most. There is even likely to be a certain attitude of mind aroused corresponding to the setting of the features in a particular way. While this is true for almost any other expressive state of the countenance, it is not so easy to demonstrate as is this.