If he has not already done so the would-be thinker should study a work on logic, for unless the present book is supplemented by some treatise on that science it cannot be regarded as complete.
In order not to confuse the reader I shall recommend only one book. In order to encourage him I shall recommend a small book, one not so deep as to be incomprehensible or repulsive to the beginner, but at the same time one which is recognized as a standard treatise:—Elementary Lessons in Logic, by Stanley Jevons.
IV CONCENTRATION
What is the hardest task in the world? To think.—Emerson.
We have been dealing with the subject of thinking. We have considered it from both a positive and negative side. But while we have devoted our attention to thinking, we have neglected the thinker. In more scientific terms, we have treated thought from the logical side; we are now to treat it from the psychological.
Few people will admit specific faults in themselves of any kind, especially if these happen to be intellectual. But almost any man is willing to confess that he cannot always “concentrate” when he wants to, in fact, that he is one of the countless victims of “mind wandering.”
Most of us imagine we know just what we mean by both these terms. But if we are to judge by most of what has been written, no two terms are more misconceived. Before trying to find the best means of concentrating, we must first find just what we mean by concentration.
In a previous chapter I said that suggestions for solutions “occurred.” I did not say how or why. To discover this we must refer to the famous psychological principle of association.
Any train of thought is made possible by previous connections of ideas in our minds. While a girl sits at her window a parade passes along a nearby street. The band is playing, and ere the tune is completed the band has gone so far that the music is no longer audible. But the tune still goes along in her mind, and she completes it herself. It suggests a dance she had been to where it was played, and this suggests that she danced the two-step to it. The two-step suggests the more modern one-step, and this leads her to compare the familiar dancing of to-day with the distant and respectful minuet.
This is an example of a random train of ideas. It is that loose “thinking” referred to in our first chapter. But even this is made possible only by the connection of ideas in our mind at some previous period. No thought can enter our minds unless it is associated in some way with the previous thought. Psychologists have traditionally classified associations into four kinds: association by succession, by contiguity, by similarity and by contrast. The example just given involves all four. Association by succession means that when two ideas or impressions of objects have entered the mind in succession, the second is likely to be suggested whenever the first is thought of. A tune consists in a succession of notes, and when the first notes are brought to mind, as by a passing band, the rest will follow—sometimes in spite of ourselves. Association by contiguity means that when two objects or ideas have been in consciousness together, one is always likely to suggest the other thereafter. This was the case with the music and the dance, or the music and the two-step. Association by similarity occurs when two ideas resemble each other in some particular. They need not have occurred together at any past time, nor after each other. The fact that they have a common element suffices to bring up one idea when the other is in mind: thus the two-step suggested the one-step. Association by contrast needs no explanation. It is exemplified when the idea of present-day dancing brings up the idea of distant dancing.