It is plain enough to any thoughtful mind that it is not safe to judge of other people’s motives by their conversation. “Language,” said Talleyrand, “was invented for the purpose of concealing thought.” Many people conceal their real motives under a very alluring curtain of language. It seems to be the most natural thing in the world for the thief and swindler to talk with the greatest apparent earnestness and sincerity and honesty. Pious talk very frequently is the haze in which an avaricious and greedy soul hides itself. Bluff, bluster, and boasting are the sops which the coward throws to his own vanity, while the quietest, sweetest, and gentlest tones often sheath the fierce heart of the born fighter, as a velvet glove is said to clothe a hand of steel.
Motives lie at the very foundation of being. They are deeply imbedded in the very cells and fiber of the individual. They shape his thoughts, his habits, and all of his actions. It is, therefore, impossible that they should not show themselves to the practiced eye in every physical characteristic, in the tones of the voice, in the handshake, in gestures, in the walk, and in handwriting, in clothing, in the condition of the body, and in the expression of the face. So the motives of man festoon his personality with flaunting and infallible signs to be known and read by all men who care to take the trouble to learn. Some of them are so plain that there is scarcely any grown person so unobservant as not to have seen them. Others are more elusive, but none the less legible to the practiced eye.
The simpler motives, after they have held sway for years, are easily discernible. Sensuality, arrogance, vanity, coldness, benevolence, sympathy, and others are easily determined. But, in order to be successful in persuasion, you need to be able to trace all of the feelings both permanent and transitory.
There is a great practical truth in the mental law of sale now generally accepted by business psychologists and by practical men in the business world. This mental law of sale holds true in all kinds of persuasion because it describes the process of the human mind as it proceeds, step by step, from indifference or antagonism to favorable action. It is, therefore, impossible to discuss intelligently the ways and means of successful persuasion, except upon a basis of this law. Here is the law: "Favorable attention properly sustained changes into interest, interest properly intensified changes into desire, desire properly augmented ripens into decision and action.”
[Footnote 10: From “The Science of Business Building,” by A.F. Sheldon.]