Studying causes and effects, experimenting to produce effect, the hand became the principal instrument in investigation, and the prime verifier of belief. "Seeing is believing" is not nearly so accurate as "Handling is believing," for there is in touch, and especially in touch of the hands and in the arm movements, a Reality component of the first magnitude. But not only in touching and investigating, but in pushing and pulling and striking, IN CAUSING CHANGE, does the hand become the symbol and source of power and efficiency. Undoubtedly this phase of the hands' activities remained predominant for untold centuries, during which man made but slow progress in his career toward the leadership of the world. Then came the phase of tool-making and using and with that a rush of events that built the cities, bridged the waters, opened up the Little and the Big as sources of knowledge and energy for man and gave him the power which he has used,--but poorly. It is the skill of human hands upon which the mind of man depends; though we fly through the air and speed under water, some one has made the tools that made the machine we use. Therefore, the mechanical skill of man, the capacity to shape resisting material to purpose, the power of the detailed applications of the principles of movement and force are high, special functions of the intelligence. That people differ enormously in this skill, that it is not necessarily associated with other phases of intelligence are commonplaces. The dealer in abstract ideas of great value to the race may be unable to drive a nail straight, while the man who can build the most intricate mechanism out of crude iron, wood and metal may be unable to express any but the commonplaces of existence. Intelligence, acting through skill, has evolved machinery and the industrial evolution; acting to discover constant principles operating in experience, it has established science. Seeking to explain and control the world of unknown forces, it has evolved theory and practice. A very essential division of people is on the one hand those whose effort is to explain things, and who are called theorists, and those who seek to control things, the practical persons. There is a constant duel between these two types of personalities, and since the practical usually control the power of the world, the theorists and explainers have had rather a hard time of it, though they are slowly coming into their own.
Another difference between minds is this: that intelligence deals with the relations between things (this being a prime function of speech), and intelligence only becomes intellect when it is able to see the world from the standpoint of abstract ideas, such as truth, beauty, love, honor, goodness, evil, justice, race, individual, etc. The wider one can generalize correctly, the higher the intellect. The practical man rarely seeks wide generalizations because the truth of these and their value can only be demonstrated through the course of long periods of time, during which no good to the individual himself is seen. Besides which, the practical man knows that the wide generalization may be an error. Practical aims are usually immediate aims, whereas the aims of intellect are essentially remote and may project beyond the life of the thinker himself.
We speak of people as original or as the reverse, with the understanding that originality is the basis of the world's progress. To be original in thought is to add new relationships to those already accepted, or to substitute new ones for the old.
The original person is not easily credulous; he applies to traditional teaching and procedure the acid test of results. Thus the astronomers who rejected the theological idea that the earth was the center of the universe observed that eclipses could not be explained on such a basis, and Harvey, as he dissected bullocks' hearts and tied tourniquets around his arms, could not believe that Galen's teaching on circulation fitted what he saw of the veins and valves of his arm. The original observer refuses to slide over stubborn facts; authority has less influence with him than has an apple dropping downward. In another way the original thinker is constantly taking apart his experiences and readjusting the pieces into new combinations of beauty, usefulness and truth. This he does as artist, inventor and scientist. Most originality lies in the rejection of old ideas and methods as not consonant with results and experience; in the taking apart and the isolation of the components of experience (analysis) and in their reassemblage into new combinations (synthesis). The organizing activity of the original mind is high, and curiosity and interest are usually well maintained.
Unless there is with these traits the quality called good judgment (i.e., good choice), the original is merely one of those "pests" who launch half-baked reforms and projects upon a weary world.
We have spoken of intelligence as controlling and directing instinct and desire, as inhibiting emotion, as exhibiting itself in handicraftsmanship, as the builder up of abstractions and the principles of power and knowledge; we have omitted its relationship to speech. Without speech and its derivatives, man would still be a naked savage and not so well off in his struggle for existence as most of the larger animals. It is possible that we can think without words, but surely very little thinking is possible under such circumstances. One might conduct a business without definite records, but it would be a very small one.
