The simplest thinking is the comparison of objects when these are present to the senses. It prevails largely in the handicrafts and in the ordinary duties of life. More difficult is the comparison of images or mental pictures of things when these are not present to the senses, but must be recalled by the memory. This thinking is essential to the appreciation of poetry, to the vivid presentation of thought, and should not be neglected by those who wish to move the multitudes with tongue or pen. “Imaging,” says Dryden, “is in itself the very height and life of poetry, which, by a kind of enthusiasm or extraordinary emotion of the soul, makes it seem to us that we behold those things which the poet paints.” Higher, from the scientist’s point of view, is the thinking in substitute symbols which stand for ideas definitely fixed or quantified. Higher still is the comparison of abstract and general ideas through expressive symbols, including their application to the problems of life; for this is the kind of thinking that characterizes the scientist and the philosopher, the engineer and the surgeon, the editor and the orator, and, in fact, all whose vocation has risen to the rank of a profession. But highest of all is the thinking which creates and invents, begetting progress in science and art, in literature and history, in government and civilization.
XV
THE STREAM OF THOUGHT IN WRITING, SPEAKING, AND ORAL READING
The highest joy is the freedom of the mind in the living play of all its powers.
Schiller.
The historian Niebuhr, speaking of the historian’s vocation, remarks that he who calls past ages into being enjoys a bliss analogous to that of creating. With still more truth may we say of that mind which is able, in the conscious awakening of all its powers, to give full and satisfactory utterance to its thick-coming thoughts, that it enjoys the joy of a creator. If there is one bright particular hour in the life of the educated man, in the career of the scholar, it is that hour for which all other hours of student-life were made,—that hour in which he gives original and full expression to what has been slowly gendering within him.
Shedd.