Thus no one is _exclusively_ sanguine, bilious, lymphatic, or melancholic. One person could be at once bilious, melancholic and lymphatic. We sometimes see the apparently contradictory temperaments of the melancholic and sanguine in the same person, but, generally speaking, one temperament dominates, modified by one or more of the others. This makes one of the sources of the variety of character we see in those about us, no one person having precisely the same modification of temperament, to say nothing of the difference of intellectual gifts. Now, as the temperament produces the character and the character the passions, it is very necessary, in order to be a good physiognomist that we should be thoroughly expert in being able to assign to each person under judgment the exact amount of domination of each of these four temperaments and this is only to be done by noting the colour and texture of the skin and hair. Aristotle has said that though there is a certain physiognomy of the whole person, the principal signs to guide us in a knowledge of human beings are to be found on the face; and this is perhaps because the skin of the face is somewhat differently constituted to that over the other parts of the body. It is more transparent than that of the other parts of the body, and thus more readily reflects the different colours--the vivid flush of joy, the blush of shame, the livid hue of envy, the pallor of fear, the different passions by which we are agitated. The face also is the seat of the eyes and the lips, both of which features (being continually in movement) make the face, as the old Italian writer has said, "the mirror of the soul."