However, it must not be understood that this law refers only to the visible contractions of the muscles which produce the overt behavior of a man, for it equally explains the case where a very small number of nerve and muscle fibers are activated. That is to say, the law of all-or-none _and_ the law of reciprocal innervation can both operate in the face or the hand at the same time. Indeed, we must not neglect to consider that _all_ of the myriad fibers of our largest muscles are never simultaneously contracted; rather is it the rule that these fibers contract in relays,[6] thereby automatically saving us from the fatigue and exhaustion which would otherwise ensue. Moreover, the more intelligent and skilful we become, or, as we sometimes say, the more our head saves our heels, the fewer muscle fibers are required to generate and maintain any specific action-tendency. Consequently, then, the law of reciprocal innervation can be exhibited in the antagonism of extremely small muscular units, such as we have postulated to be involved in certain cases of meaning provided they be anatomically situated in the correct position for producing antagonistic strains. Now the experimental demonstration of the law of dynamogenesis at the hands of Richet, Charcot, etc., revealed that just such slight movements of an opposed character are produced when we merely “think” of _up_ and _down_, _right_ and _left_, _in_ and _out_, and the like. In every case of this sort, some part of the movable, skeletal system performs overtly or covertly the appropriate movement, thereby giving meaning to the word. We may therefore, unless we read all signs incorrectly, safely affirm that whatever be the action-pattern which any abstract term arouses in us, the antonym of that term, if indeed it be its logical and physiological antonym, arouses action-patterns of an opposite character. Our physiological explanation of the meaning of words and the contradiction of antonyms is now complete. For if, as we have previously shown, even abstract terms acquire and keep their meaning by virtue of the reflex tendencies which they arouse, it is likewise apparent that the basis of logical opposition and contradiction is to be found by an examination of the baldest facts of the physics and physiology of the human body. In brief, then, _antonyms are those words whose utterance stimulates us so to react as to illustrate the law of reciprocal innervation_. And this, moreover, is the only reason why _cheap_ is the opposite of _expensive_, _true_ the contradictory of _false_, and _good_ the antithesis of _bad_.