Man's interest in character is founded on an intensely practical need. In whatsoever relationship we deal with our fellows, we base our intercourse largely on our understanding of their characters. The trader asks concerning his customer, Is he honest? and the teacher asks about the pupil, Is he earnest? The friend bases his friendship on his good opinion of his friend; the foe seeks to know the weak points in the hated one's make-up; and the maiden yearning for her lover whispers to, herself, Is he true? Upon our success in reading the character of others, upon our understanding of ourselves hangs a good deal of our life's success or failure.