2. As deduced from Class B. Here the word “right” is used to describe the method or object by which any desire may be realized. The requirements for membership in this class appear at first to be less rigid than was the case with Class A. The speed of motion that was stressed in the former class is inessential here, as well as the necessity of proceeding by the shortest course. Here also a beefy body is not as imperative as are skill and sagacity. But let us not make a favorite of either class before we have heard the whole story. And first let us ask, what is the typical action-pattern implied by Class B? The answer is not difficult to give. There is a phrase, “selective excitability,” which psychologists have long applied to the situation where a sensori-motor mechanism is attuned by practice to respond to one specific stimulus, and to be entirely unresponsive to others. We exhibit this selective excitability every time we take “our” hat from the crowded coat-room, choose “our” favorite cigar from a case full of attractive Havanas, or fumble thoughtfully in “our” pocket for a cent to give to the crouching beggar. In every such case, we are said to employ the “right” object and perform the “right” action. Actions of this sort involve choice, which as we have already hinted (See footnote, p. 32, Chap. II.), involves the use of one member of a pair of antagonistic muscles. Consequently, we may describe the action-pattern underlying the use of “right” in Class B as any sort of behavior which involves selective excitability and selective activity. So that whatever Class B lacks in generality as compared with Class A, is compensated for by an increase in precision and, what is equally important, by an _economy_ of human energy in the pursuit of the desired object. The importance of this last factor has already been sufficiently hinted at in the quotation that appears on the title-page of this book. 3. As deduced from Class C. The change from Class A to Class B involved an increase in what is known as intelligence, that is, the ability to solve new problems. The change to Class C may be regarded as involving a continued advance of the same general character. But this change involves something more. For, as we have already stated, “right” now becomes “descriptive of any statement which reports the facts: of any opinion or judgment that is correct: and of any person who judges, thinks, or acts in accordance with the facts or truth of a matter.” Two changes in emphasis are consequently to be noted here. First, the word “right” is applied to utterances rather than to deeds alone; and second, a metonomy is introduced in the application of our concept to persons who make correct statements. This shift of emphasis from an action to the description of it, and from the description to the describer need not cause us any difficulty, even though it envisages for us a million years of the education of the human race.