When, therefore, a man hates his work, when he is dissatisfied and discontented in it, when his work arouses him to destructive thoughts and feelings, rather than constructive, there is something wrong, something abnormal, and the abnormality is his attempt to do work for which he is unfitted by natural aptitudes or by training. The man who is trying to do work for which he is unfitted feels repressed, baffled and defeated. He may not even guess his unfitness, but he does feel its manifold effect. He lacks interest in his work and, therefore, that most vital factor in personal efficiency--incentive. He cannot throw himself into his work with a whole heart. When Thomas A. Edison is bent upon realizing one of his ideas, his absorption in his work exemplifies Emerson's dictum: "Nothing great was ever accomplished without enthusiasm. The way of life is wonderful--it is by abandonment." He shuts himself away from all interruption in his laboratory; he works for hours oblivious of everything but his idea. Even the demands of his body for food and sleep do not rise above the threshold of consciousness. Edison himself says that great achievement is a result, not of genius, but of this kind of concentration in work--and, until the mediocre man has worked as has Edison, he cannot prove the contrary. Mr. Edison has results to prove the value of his way of working. Even our most expert statisticians and mathematicians would find it difficult to calculate, accurately, the amount of material wealth this one worker has added to humanity's store. Of the unseen but higher values in culture, in knowledge, in the spread of civilization, and in greater joy of living for millions of people, there are even greater riches. Other men of the past and present, in every phase of activity, have demonstrated that such an utter abandonment to one's tasks is the keynote of efficiency and achievement. But such abandonment is impossible to the man who is doing work into which he cannot throw his best and greatest powers--which claims only his poorest and weakest. This man's very failure to achieve increases his unrest and unhappiness. Walter Dill Scott, the psychologist, in his excellent book, "Increasing Human Efficiency in Business," gives loyalty and concentration as two of the important factors in human efficiency. But loyalty pre-supposes the giving of a man's best. Concentration demands interest and enthusiasm. These are products of a love of the work to be done.