Intuition is the faculty of the Mind whereby it evolves what have been called Primary Truths or Primary Ideas. By Primary Ideas are meant the ideas of Space, Time, Cause, Identity, etc. By Primary Truths are meant the so-called "Self-Evident Truths" of geometry, mathematics and logic. Under the head of Intuition are also sometimes included the activities of the Subconscious or Superconscious regions of the mind, of which we have spoken in detail in a volume under that name of this series. Some authorities hold to the older idea of "Innate Ideas" by which is meant that every human being is born with the knowledge of certain fundamental truths, unconnected with any experience. Others hold that these ideas are simply the result of the experience of the race, transmitted to us as "germ ideas" which must grow by experience and exercise.
That each and every faculty of the Mind may be strengthened and developed by Culture and Exercise is now held to be a fact by nearly every authority worthy of that name. Just as the physical muscle may be cultivated by the proper methods, so may the mental faculties be strengthened and cultivated by the appropriate methods and means. Inasmuch as the majority of the race are deficient in the development of one or more of the leading mental faculties, it becomes a matter of great interest and importance that all should acquaint themselves with the means whereby their deficiencies may be corrected and remedied. We shall now proceed to the consideration of Thought-Culture in general, and then to the consideration of the culture of each particular general faculty, in detail.
CHAPTER IV
THOUGHT-CULTURE
Thought-Culture is based upon two general scientific facts which may be stated as follows:
I. The brain centres of thought may be developed by exercise. While we do not assert that the brain and the mind are identical, it is nevertheless a scientific truth that "the brain is the organ of the mind" and that one of the first requisites for a good mind is a good brain. It has been proven by experiment that the brain-cells concerned in special mental activities multiply in proportion to the active use of the special faculties employed in the mental operation. It has also been ascertained that disuse of special faculties of the mind tends to cause a process akin to atrophy in the brain-cells concerned in the particular activity, so that it becomes difficult to think clearly along those particular lines after a long period of disuse. Moreover, it is known that the education and mental culture of a child is accompanied by an increase and development of the brain-cells connected with the particular fields of thought in which the child is exercised.
There is a close analogy between the exercise of the brain-cells and the exercise of the muscles of the body. Both respond to reasonable exercise; both are injured by overwork; both degenerate by disuse. As Brooks says: "The mind grows by its own inherent energies. Mental exercise is thus the law of mental development. As a muscle grows strong by use, so any faculty of the mind is developed by its proper use and exercise. An inactive mind, like an unused muscle, becomes weak and unskilful. Hang the arm in a sling and the muscle becomes flabby and loses its vigor and skill; let the mind remain inactive and it acquires a mental flabbiness that unfits it for any severe or prolonged activity. An idle mind loses its tone and strength like an unused muscle; the mental powers go to rust through idleness and inaction. To develop the faculties of the mind and secure their highest activity and efficiency, there must be a constant and judicious exercise of these faculties. The object of culture is to stimulate and direct the activity of the mind."
Experiments conducted by scientists upon dogs have shown that in the case of dogs specially trained to unusual mental activity, there has been a corresponding increase of the number of active brain-cells in the particular parts of the brain concerned with those mental activities. Microscopic examination of the brain tissues showed the greatest difference between the brain structure of the trained dogs and untrained ones of the same brood. So carefully were the experiments conducted that it was possible to distinguish between the dogs trained in one set of activities from those trained in another. Biologists have demonstrated the correctness of the brain-cell development theory beyond reasonable doubt, and ordinary human experience also adds its testimony in its favor.
In view of the above, it will be seen that by intelligent exercise and use any and all faculties of the mind may be developed and cultivated, just as may any special muscle of the body. And this exercise can come only from actual use of the faculties themselves. Development must come from within and not from without. No system of outward stimulation will develop the faculties of the mind – they may be cultivated only by an exercise in their own particular field of work. The only way to exercise any particular faculty of thought is to think through that faculty.
II. Not only are the brain-cells developed by exercise, but it also appears to be a fact that the mind appears actually to be nourished by knowledge of the outside world of things. The raw material of thought is taken into the mind and there is digested by the thought-processes, and is afterward actually assimilated by the mind in a manner strikingly similar to the processes of the physical organs of nutrition. A mind to be at its best must be supplied with a normal amount of mental nourishment. Lacking this, it tends to become weak and inefficient. And, likewise, if its owner is a mental glutton and furnishes too much nourishment, particularly of a rich kind, there is a tendency toward "mental dyspepsia" and indigestion – the mind, unable to assimilate the mental food furnished it, is inclined to rebel. Moreover, if the mind be supplied with mental food of only one kind – if the mind is confined to one narrow field of thought – it weakens and the mental processes become impaired. In many ways is this curious analogy apparent.
Not only does the mind need development, but it also needs intelligent cultivation. For it may be developed by improper objects of thought just as well as by the proper ones. A rich field will grow tares and weeds as well as good grain or fruit. Thought-culture should not be confined to the development of a strong and active mind, but should be also extended to the cultivation of a wise and intelligent mind. Strength and Wisdom should be combined. Moreover there should be sought a harmonious and normal development. A one-sided, mental development is apt to produce a "crank," while a development in unhealthy mental fields will produce an abnormal thinker tending dangerously near to the line of insanity. Some "one-idea" men have great mental power and development, but are nevertheless unbalanced and impractical. And insane persons often have strongly developed minds – developed abnormally.
Some authorities, holding special theories regarding the nature of mind, hold that Thought-Culture is merely a training of the faculties rather than a creation of new mental power, inasmuch as the mind cannot be built up from the outside. This is a curious combination of truth and error. It is true that the mind cannot be built up from outside material, in the sense of creating new mind, but it is also true that in every mind there is the potentiality of growth and development. Just as the future oak is said to be in the acorn, so are the potentialities of mind-growth in every mind waiting for nourishment from outside and the proper cultivation. Brooks has well stated this, as follows: "The culture of the mind is not creative in its character; its object is to develop existing possibilities into realities. The mind possesses innate powers which may be awakened into a natural activity. The design of culture is to aid nature in improving the powers she has given. No new power can be created by culture; we can increase the activity of these powers, but cannot develop any new activities. Through these activities new ideas and thoughts may be developed, and the sum of human knowledge increased; but this is accomplished by a high activity of the natural powers with which the mind is endowed, and not by the culture of new powers. The profound philosopher uses the same faculties that the little child is developing in the games of the nursery. The object of culture is to arouse the powers which nature has given us into a normal activity and to stimulate and guide them in their unfolding."
In connection with the objection above mentioned, it may be said that while the development of the mind must come from within itself, rather than from without, nevertheless, in order to develop, it must have the nourishing material from the outside world in order to grow. Just as the body can grow from within only by the aid of nourishment from outside, so the mind, while growing from within, needs the material for thought which can come only from without itself. Thought requires "things" upon which to exercise itself – and upon which it is nourished. Without these outside objects, it can have no exercise and can receive no nourishment. Thought