Directly, perhaps, there is little to be done, but indirectly a great deal. For, after all, it is not these mathematical diagrams which we have been describing that make up beauty. It is expression, the soul, if you will, shining through its mortal coil.
And here we have no longer to do with unyielding bone and solid flesh, but with material infinitely more plastic than even the tempered clay in which the sculptor forms his model. The vast majority of persons are neither repulsive nor beautiful in feature, and it is the expression of their faces which grants or denies them popularity and success. Therefore this is a most weighty branch of our theme, and all the more so because expression is very much under our own control, if we only know it.
For what makes expression? Chiefly the action of certain muscles of the face. Why it is that joy or sadness, love or hate, fear or anger, should each call into action a particular muscle on this prominent and visible part of the human frame, we do not know. But the fact can be shown by this strange experiment: Connect the poles of an electric battery with these separate muscles on the face of a corpse, and you will see the ghastly spectacle of the passions of rage, of mirth, of lust, of hate, one after another brought into horrid relief on the countenance of death.
The habitual use of one of these muscles above the other, enlarges it, and leaves on the countenance marks
