“We are always talking about originality, but what do we mean? As soon as we are born the world begins to work upon us, and this goes on to the end. After all, what can we call our own except our energy, strength, and will? If I could give an account of all that I owe to great predecessors and contemporaries, there would be little left of my own.”

Observation lies at the basis of the thinking which leads to invention in the arts, to discovery in the domain of science, to productivity in the fields of literature, journalism, and oratory. It lies at the foundation of success in the professions and in the ordinary walks of life. The medical school, for instance, seeks to develop the power of noting facts and making careful observations. It encourages the student to put his observations on paper while the patient is before him, to compare the diseased or injured part with the corresponding healthy part, and to watch symptoms as a basis for a correct diagnosis of the case to be treated.

The use of the encyclopædia, if pursued without any attempt to verify its statements, may destroy the habits of observation which are so essential to correct thinking. Mere reliance on books cannot beget trustworthy habits of thought, for books contain the errors, as well as the wisdom, of the ages. Errors of judgment may be corrected by thinking; errors of fact must be corrected by observation. Many a book is made useless by new observations and discoveries. “Send to the cellar as useless every book on surgery that is eight years old,” said the professor to the librarian of a great university. The order is an indication of the rapid advances which science is making under the influence of observation, experiment, hypothesis, and verification. Observation is needed not merely to extend our scientific knowledge, but far more imperatively to acquaint us with our environment. We cannot learn from books the multitudinous details of business, or of our daily life. Books cannot make us acquainted with the circle of friends in which we move, the pupils whom we teach, the things in dress, toilet, and behavior upon which our standing and reputation very largely depend. No thinker has a right to neglect these. Many a famous professor has diminished his usefulness by carelessness in the observation of such details. The worst failures in the class-room are due to failure in observing either the difficulties or the conduct of the pupils. If conduct is to be regulated, it must be observed; if difficulties are to be explained, the teacher must perceive when and where they occur.

Men noted for their absent-mindedness nevertheless owe much of their fame and success to their ability to make accurate observations in favorite lines of study. Notwithstanding the many ludicrous tales about Newton’s failure to see ordinary conditions and circumstances, he showed himself indefatigable in watching the effect of a glass prism upon the ray of light admitted into a dark room. The falling of an apple started in his mind a train of thought which led to the discovery of the law of gravitation.

Our best thinking is based upon experience, and our two main sources of experience are observation and experiment. How does experiment differ from simple observation? In the latter we watch conditions, phenomena, and sequences as they follow one another in the ordinary course of nature. In an experiment we change or control the course of nature by varying the conditions and causes for the sake of seeing the effects produced. In experiment the relation of causes and effects is studied by adding or excluding one factor after another. Take the discovery which made Daguerre famous. Up to his time men had tried in vain to fix the impression of the image formed in the camera obscura. No alchemist ever went to work at a more unpromising task than the one Daguerre set before himself. “As years rolled on, the passion only took deeper hold upon him. In spite of utter failures and discouragement of all kinds, for years in loneliness and secrecy, suspected of mental weakness even by his wife, he kept on in the same line of experiment.” Finally an accident gave him a clue to discovery. The plates with which he experimented were stowed away in a rubbish closet. One day he found, to his surprise, upon one of these plates the very image which had fallen upon it in the camera. Something in the closet must have produced the effect. He removed one thing after another, getting the same effect, until nothing remained except some mercury which had been spilled upon the closet floor. This was inferred to be the agent which developed the image, and thus was laid the foundation of the modern art of photography.[20]

The observation of a fact often stimulates thought in new directions. In fact, new sciences have arisen from accidental observations. “Erasmus Bartholinus thus first discovered double refraction in Iceland spar; Galvini noticed the twitching of a frog’s leg; Oken was struck by the form of a vertebra; Malus accidentally examined light reflected from a distant window with a double refracting substance; and Sir John Herschel’s attention was drawn to the peculiar appearance of a solution of quinine sulphate. In earlier times there must have been some one who first noticed the strange behavior of a loadstone, or the unaccountable motions produced by amber. As a general rule we shall not know in what direction to look for a great body of phenomena widely different from those familiar to us. Chance, then, must give us the starting-point; but one accidental observation well used may lead us to make thousands of observations in an intentional and organized manner, and thus a science may be gradually worked from the smallest opening.”[21]

In recent years experimental research has become a regular occupation in connection with large manufacturing establishments. In some factories along the Rhine upward of sixty men are employed in chemical experiments for the purpose of finding what use can be made of waste products. In this way over two hundred useful products from petroleum have been discovered, and a large increase in profits has been the result. The great electrical works spend time and money upon experiments, and jealously censor every article written by their employees for scientific journals lest their valuable secrets should be given away. A company engaged in the manufacture of cash registers offers a yearly premium for the most helpful suggestion from the men and women in its employ. In one year the firm received over eleven hundred suggestions, of which at least eight hundred were utilized in improvements of various kinds.

These instances are only samples of many that could be cited to show how systematic observation and experiment lend a helping hand to our national prosperity. Manufacturers carry them on for the sake of gain, the universities for the sake of widening the field of knowledge. To aid in such research large endowments have been established, and many of the common people willingly pay tax in support of State universities. Treatises on inductive logic and on the physical sciences have been prepared by Herschel, J. S. Mill, Jevons, and others for the purpose of showing the correct methods of research by the use of instruments of precision, of standards of measurement, and of other apparatus; for the laws of thought must be obeyed in the interpretation of natural phenomena. Although as a matter of discipline the teacher in our public schools may well study these advanced treatises, yet the habits of observation which the elementary school should aim to beget and to foster are simpler in detail, more easily acquired, and, it may be added, of inestimable value in the subsequent life of the pupils. Habits of observation are needed not only by authors, inventors, and scientists, but also by all other people for the interpretation of the books they may read and for the discharge of the daily duties devolving upon them. The engineer, the fireman, the conductor, the tradesman, the mechanic, the detective, the scout, the warrior, must be able to see things as they are or face partial failure. Too many of them have eyes and see not; they have ears and hear not. The study of nature is valuable as a preparation for life either in the country or in the city. Our rural population have not learned to see and appreciate the marvels in nature which are transpiring on every side. The way in which the almanac is consulted for signs to guide in sowing and planting, for prognostications of the weather, show how little the average man can make observations. The printers have found it necessary to retain these absolutely unreliable weather predictions in their almanacs; the attempted omission has been an experiment involving the loss of thousands of dollars. The success of the quack is largely due to limited observation. One cure is made much of while multitudes of failures are always forgotten.

Our rural population would be far more contented if the boys and girls were taught at school how to observe and appreciate their surroundings. They have many advantages over city folks which they never realize as sources of enjoyment. The senses themselves, which have been styled the gate-ways of knowledge, may be improved by judicious exercise; and the power of the mind to interpret sense-impressions may be developed to a marvellous degree. The savages of our North American forests had developed keen eyes and ears; the more civilized backwoodsmen were soon more than a match for the wily Indian. To-day, when the latter watches the trained sharp-shooters hitting with unerring accuracy a mark more than half a mile distant, he shakes his head and walks away in silence.

It has been asserted that a child gains more knowledge in the first seven years of its life than in all its subsequent days. If the domain of abstract and scientific knowledge be excluded from the comparison, this is probably true. At any rate, if the thinking which is based upon the knowledge of facts thus gained is to be correct, the facts must be correctly observed.

Observation is thus of prime importance, not merely as furnishing a stimulus to thought, but also as supplying abundant materials of thought. Travel, experience, experiment, as well as the ordinary course of natural phenomena, furnish abundant opportunity for the formation of correct habits of observation. The observations thus made should be recorded in the memory, if not on manuscript. From the storehouse of the memory, thus filled with materials for thought, the mind derives many of the best data for reaching conclusions. Observation, experience, and reading, as sources of thought-material, presuppose an accurate and retentive memory in those who think well and act well. The relation of memory to thinking deserves treatment in a separate chapter.