2. OBSERVATION.

Facts are acquired by means of observation. When the mind fixes the attention upon any phenomenon it observes it. The term observation means “to watch for” and may be defined as the act of watching for phenomena as they may occur. The observation may be only casual, or it may be willed or rational. It is the latter aspect which most concerns the logician. In this sense observation means careful, painstaking, systematic perception. It involves the concentration of consciousness upon the case in hand, or the actual giving of attention. The thing observed may be external, when the observation takes the form of sense-perception; or it may be internal, when the observation becomes a matter of introspection.

3. EXPERIMENT.

In observation we simply watch the phenomenon; in experiment we make it. In experiment we not only observe, but we manipulate the circumstances so as to present the phenomenon under the most favorable conditions for observation. “In observation,” says Mill, “we find an instance in nature suited to our purposes”; whilst in experiment, by an artificial arrangement of circumstances, we make an instance suited to our purpose. In observation we watch for causes; in experiment we work for effects. We may thus define experiment as the act of making phenomena occur for the purpose of watching for effects. In experiment there is much which is merely observation. In fact experiment is observation in which the phenomenon is artificially produced. For the sake of definiteness, however, any observation which involves a manipulation of circumstances, may be designated as experimental.

4. RULES FOR LOGICAL OBSERVATION AND EXPERIMENT.

To the uninitiated, the matter of observation seems an easy task, and yet when one hears two honest men swear to diametrically opposite facts which have come to them from observing the same phenomenon, his faith is shaken. “Eyes have they but see not” is a logical truth as well as a moral one. Only the observation of the trained can be depended upon; and yet this should not discourage the layman, for even he, by a little conscientious effort towards careful observation, may greatly increase his store of accurate knowledge and add to the joy of living.

The attending rules are usually heeded by the trained scientist in matters of observation and experiment:

First Rule. The observations should be precise. The time, the place, the surrounding conditions must be accurately noted. Many artificial contrivances have been devised because of the desire of the scientist to be precise. Instruments like the balance, the thermometer, the microscope, etc., has he invented, and various devices and methods has he adopted for the sake of precision. Acommon method is to take an average of observations. For example, to estimate justly the class work of a student, the teacher should not be content with the ratings of one or two recitations, but must average the ratings of many recitations. Again, a child may be led to discover approximately the value of the sum of the interior angles of a triangle by measuring the angles of many triangles and then striking an average; assume that the following results are obtained by such a procedure: (1)178, (2)181, (3)179, (4)180, (5)182; adding these and dividing by 5 gives 180.

Second Rule. The observations should concern only the material circumstances of the case in hand. All the non essentials may be ignored, as they serve only to distract attention. For example, (1)in order to get the “right count” all other sounds must be ignored save that of the fire gong; (2)in finding the depth of the water for the building of a dam, soundings ten miles away from the objective point could be of little value. On the other hand, it is easy to overlook certain lurking essentials. To observe such, it is necessary to resort to what the psychologist terms a “preadjustment of attention.” We must know with exactness what we are looking for. We must have a mental image of what we wish to see. The astronomer in the discovery of a new planet must know the exact spot where it ought to be, and have a clear mental image of its appearance. This expectant attention is a necessity in the case of the physician who is anxious to make no mistakes in his diagnosis. If he is looking for pneumonia, he must have a very distinct auditory image of the sound of an affected lung. It should be remarked, however, that this very preadjustment of attention, with the untrained, frequently leads to illusion. We are so anxious to see what we are looking for that nine-tenths of what we believe we see is only inference. How easy it is to read into a phenomenon something that is entirely foreign to it; to read between the lines; to see only the reflection of our own ideas. “Verily the mental picture of what we wish to see becomes so vivid that we are positive of the thing being external.” Thus the drunkard sees snakes and the superstitious see ghosts. Reading into the external what is only vividly internal is probably the most common error with the untrained observer.

Third Rule. The observed circumstances should be varied as much as possible. To observe a fact from a different viewpoint may not only broaden the original notion, but it may change it entirely. In order to gain a true notion of the effect of a particular nostrum on the human organism, it becomes necessary to experiment with persons of different ages, living under different environments, and inheriting different constitutions. Those who are noted for pronouncing broad, safe and sane judgments upon momentous questions are those who are “all-angled observers.”

Fourth Rule. The observed phenomenon should, if possible, be isolated from all interfering phenomena.

In studying the action of a drug or a food, all other drugs or foods must be eliminated. The effect of gravitation on a body cannot be recorded accurately unless the experiments are made in a vacuum. When studying the deflections of the compass, all magnetic substances must be removed from the field.

5. COMMON ERRORS OF OBSERVATION AND EXPERIMENT.

The rules for scientific observation have suggested certain common errors which may now be considered.

(1) Preconceived ideas.

There is not an unholy belief nor an unwholesome theory which cannot be bolstered up by means of apparent facts. For example, that monstrosity of Puritan thought known as “Salem Witchcraft” was substantiated by facts honestly observed. Again, having made up his mind that it is going to be “so and so,” the statistician goes out into the highways and byways and gathers the facts which vindicate his judgment. Further, the democrat finds that the majority of the voters are democrats; while the republican is confident that two-thirds of the voters are for republicanism. Here again is the fallacy springing from a preadjustment of attention. We see what we want to see. Only the highly trained observer is able, with impunity, to make use of preadjusted attention, and even with him, it is not easy to remove from the situation belief and prejudice.

The true observer undertakes his work with his mind open to anything which the eye may bring him, though it may topple into the dust his dearest theory and most cherished belief; he proceeds—the mind a “clean white page.”

(2) The “observed” and the “inferred” confused.

This error has already received some attention. It may be remarked further, however, that, psychologically considered, observation is a matter of interpreting the new by means of the old. Of necessity the interpretation, whatever it may be, will assume the complexion of the particular “old knowledge” which the mind is able to use. In short, a man will see what his previous environment has trained him to see; the conscientious gardener sees the weeds, whilst the artist may see nothing but the flowers. It follows, therefore, that all observation must be largely a matter of inference based on experience. In looking at the moon, for example, all Iactually see is a patch of color; the form and distant location of the moon being a matter of experience.

The inference referred to in this heading is not that which is necessary for perception, but that which is suggested by perception. To illustrate: It is icy; three men are running for a car; Smith raises his arm; Jones slips to the ground; and Brown testifies, that “Smith knocked Jones down.” Brown observed, that Smith assumed the proper attitude and that Jones conveniently went down at the right time; and then inferred the rest.

(3) Ignoring the exceptions.

This comes through an over anxiety to prove our theory. With this mental attitude, the observations which are corroborative will so completely fill the mental field, that the exceptions are made to seem of no consequence. This accounts for the superstition attached to thirteen. As a coincidence some one at some time died who had previously eaten at a table where there were thirteen. Perhaps during the life of the superstitious one this happened on two or three occasions, but the fact so impresses the subject that he ignores the dozen times when death did not follow. Other generalizations belonging to this class are (1)people never die at flood tide; (2)there must be three accidents in succession; (3)the first sight of the new moon over the right shoulder is a good omen; (4)seeds which grow to root do best when planted during the last days of the waxing moon; (5)horse chestnut in pocket guards against sore throat, etc.

(4) Sympathy and undue interest.

The influence of the heart over the brain is well known. Aphysician is liable to this error when he attempts to prescribe for one of his own family. Sympathy not only warps the judgment but it may actually interfere with the accuracy of an honest observer’s perceptive powers.

(5) Inattention and a fallible memory.

These short comings are too apparent to demand discussion.

6. THE HYPOTHESIS.

Having observed the facts, the mind naturally seeks for explanation of the same. Hence taking the facts as a cue and bringing into play a constructive imagination, a plausible supposition is advanced, which is then proved or disproved. Such a supposition is known as an hypothesis.

Definition. An hypothesis is a supposition advanced for purposes of explanation and proof.

First illustration. The facts are known that light travels from the sun to the earth, and at the rate of 186 thousand miles per second. These facts suggest the problems: (1)How does the light reach the earth? (2)Why this rate of speed; why so much faster than the rate at which sound travels? To solve these problems, or to explain the facts, the “ether” hypothesis is advanced: viz., “Arare medium called ether pervades space and transmits the light and heat of the sun.” This hypothesis has never been conclusively proved.

Second illustration. Fact: The child leans forward and squints his eyes, when attempting to read work which has been placed on the black board; hypothesis: The child is near sighted.

7. INDUCTION AND HYPOTHESIS DISTINGUISHED.

Induction is a matter of realizing generalizations from the observation of facts. The product of such is an induction, but we know that an hypothesis is likewise a generalization based upon facts. What is the difference? An induction, as such, is a broader term than hypothesis. As soon as the hypothesis is proved or disproved, it ceases to be an hypothesis, but still remains an induction. An hypothesis, being advanced for purposes of explanation ceases to be an hypothesis when, in the last analysis, it fails to explain. Moreover, as soon as the hypothesis is shown to be an undoubted truth, it also loses its distinctive hypothetic marks. An hypothesis is merely a tentative induction.

ILLUSTRATIONS:

(1) The hypothesis is advanced that the fire started from the coal range in the kitchen. After the incendiary is caught, this supposition ceases to be an hypothesis.

(2) It is suspected, that my insomnia is due to the three cups of strong coffee indulged in at the evening meal. As soon as this supposition is proved by experimental means (law of difference), it ceases to be an hypothesis and becomes an unpopular inductive truth.

8. HYPOTHESIS AND THEORY.

In common parlance hypothesis and theory are used interchangeably. We refer to the “nebular hypothesis” or the “nebular theory”; to the “hypothesis of the sun’s heat” or “the theory of the sun’s heat.” On the other hand, we say “the theory of gravitation,” “the theory of evolution,” etc., with certain uniformity. From these observations we may infer that hypothesis and theory may be used interchangeably when the facts are of a low probability; but when the facts have undergone cogent verification, it is more correct to use theory in their designation rather than hypothesis. “A theory is a partially verified hypothesis.” It has been remarked that theory has a second signification of being a term which stands for “any body of acquired truth.” It is unfortunate that its use could not be confined to this latter conception.

9. THE REQUIREMENTS OF A PERMISSIBLE HYPOTHESIS.

Any hypothesis should be made to conform to the following requisites: (1)The hypothesis must be conceivable. The hypothetic generalizations of primeval days were mere fancy. For example, the loud noise from the clouds on dark days was the angry voice of the God of the skies. Even in this day when a complex situation cannot be explained there comes the temptation to draw entirely upon the imagination, and advance an hypothesis which is absurd in every sense of the word. The permissible hypothesis demands that there be some ground for the conjecture. Afact or two at least must be used as the foundation for whatever the constructive imagination may build. On the other hand the past has taught us that we cannot afford to be too exacting in the enforcement of this rule. The ideas of Copernicus, Newton, Harvey, Darwin, and many another of the world’s best thinkers, were looked upon at first as being ridiculous. There is always a bare possibility of a “lurking truth” in the conjecture, and no broad minded and sanely educated man can afford to scoff blindly at something which may seem to him mere fancy. Prejudice and a willful blindness to truth, have ever been imminent stumbling blocks in the path of progress.

(2) The hypothesis must be capable of proof or disproof. This means, that where it is possible the hypothesis should touch, in one form or another, our experience. If the hypothesis is wholly unlike any experience we may have had, it becomes impossible to ascertain, whether it agrees or disagrees with the facts, which it is supposed to explain. Alegitimate hypothesis must furnish some opportunity for securing facts to prove or disprove it. For example, to advance an hypothesis relative to the conditions of the next world is hardly permissible, as “spirit-facts” are entirely without our field of experience. Surely, one returning from Heaven could give us no conception of it; because there is nothing in the carnal mind that may be used to interpret the experiences that must function in the Celestial City.

(3) The hypothesis must be adequate. It should take into consideration all the known facts. It stands to reason that, if one known fact is ignored, the entire procedure is thus vitiated. It would be absurd to suppose the moon to be inhabited without giving heed to the fact of its having no atmosphere.

(4) The hypothesis must be as simple as possible. We must, of course, recognize situations which in themselves are too complex to admit of simple conjectures. The purport of the fourth rule is, that the hypothesis should not be made unnecessarily complex.

(5) The hypothesis should not contradict any verified truth. Any conjecture which opposed the law of gravitation would be out of place. Of course it is possible to have only apparent conflicts between the new hypothesis and the old law. Further observation should show that no such clash exists.

10. THE USES OF HYPOTHESES.

The hypothesis is serviceable mainly in these particulars:

(1) As a working basis.

When one is confronted with a huge mass of facts it becomes necessary to start somewhere, and with as little waste of time and energy as possible. Almost anything is better than a haphazard floundering which reaches “nowhere.” So the investigator hazards a tentative theory, which he at once proceeds to verify. If verification fails, then he may discard this first hypothesis for a better one.

(2) As a guide to ultimate truth.

Much might be said relative to the use of rejected hypotheses. By means of these, science has advanced step by step towards the full light of perfect knowledge. As has been remarked, no true scientist cares to overlook the opportunity for suggestive inspiration which some forsaken hypothesis may afford him. Just as the individual attains the best success by using his failures as stepping stones, so the true scientific discoverer climbs up to the light on the stairway of discarded hypotheses. By testing and rejecting the false hypotheses, the situation becomes more definite and the problem more accurately defined. “Kepler himself tried no less than nineteen different hypotheses before he hit upon the right one, and his ultimate success was doubtless in no slight degree due to his unsuccessful efforts.”

(3) As a discoverer of immediate truth.

Often, moreover, the hypothesis leads directly to positive verification. The supposition advanced may hit the truth squarely; and may be of such peculiar nature as to lead easily to clear and conclusive proof.

(4) As affording a probable explanation of a problem which will not lend itself to an entirely satisfactory solution.

The theory of evolution may illustrate this fourth use; while the history of the discovery of Neptune illustrates the third.

11. CHARACTERISTICS NEEDED BY SCIENTIFIC INVESTIGATORS.

The hypothesis is referred to “as the great instrument of science.” The greatest thinkers of time have possessed the courage and the conscience to step from the known to the unknown; to hazard a guess as to the meaning of what they saw, and then subject their guess to a rigorous test. This procedure involves three elements on the part of the investigator: (1)Power of accurate observation. (2)Constructive imagination. (3)A passion for truth.

(1) An hypothesis formed without an accurate knowledge of facts is not only useless, but often it may work positive harm. To advance serviceable suppositions which are not grounded on fact, is as impossible, as it is to build a house without a foundation. The hypothesis is an image of the constructive imagination, but the pedestal of this image must rest on the ground of fact. The investigator who would be scientific must exercise scrupulous care in securing his facts through observation and experiment. The rules and errors involved in such a procedure have received sufficient attention.

(2) After the investigator has his facts to build upon; and these may be few or many—sometimes even a single fact is sufficient—then may he theorize as to a possible explanation of them. Here is where the real work of the born genius tells. To some the facts are nothing but words, to others they mean universal laws and great inventions. Who but a Newton could have seen the law of gravitation in the falling apple? Who but an Edison could have seen the phonograph in the sound wave and wax? It must be recognized that this remarkable imaginative insight is inborn in some cases; and yet this does not preclude the necessity for cultivating this power, though it may be only in a rudimentary state. Here is another opportunity for the school teacher; namely, to train in every legitimate way the constructive imagination.

(3) Having once constructed the hypothesis, the honest scientific investigator at once proceeds to subject it to a series of most rigorous tests. It is well to see big things in a little fact; to have a mind as fertile in new ideas as a watered garden—this is genius! But is it not more incumbent to have a conscience so keen, that nothing will be allowed to pass for truth which has not received ample verification? Intellectual dishonesty is quite as common as moral dishonesty. Moreover, one must maintain an open mind, absolute candor, and a willingness to abandon the most cherished theory. Often it is much easier to explain away contradictory facts than it is to forsake a pet theory.

12. OUTLINE.

THE AUXILIARY ELEMENTS IN INDUCTION—?OBSERVATION—?EXPERIMENT—?HYPOTHESIS.

13. SUMMARY.

(1) Facts are the foundation of all inductive generalizations. Induction is largely a matter of building general notions from individual notions derived from the observation of facts.

(2) Observation is the act of watching the phenomena as they may occur. It involves the voluntary concentration of consciousness on the case in hand.

(3) Experiment is the act of making phenomena occur for the purpose of watching for effects. It is in reality a form of observation which necessitates a manipulation of circumstances.

(4) The average man is not given to careful observation. The rules adopted by scientific observers are: (1)The observation should be precise; (2)should concern only the material circumstances; (3)should be varied; (4)should be isolated.

For the sake of precision many instruments have been invented and methods devised; notably instruments for accurate measurements, such as the balance and thermometer, and methods like the method of averages.

Frequently a situation may be so complicated as to demand a “preadjustment of attention.” With the untrained this very preadjustment may lead to serious error.

An “all-angled observer” is the most trustworthy.

(5) Errors in observation come from preconceived ideas; confusing perception with inference; ignoring the exceptions; sympathy; inattention; and a fallible memory.

(6) An hypothesis is a supposition advanced for purposes of explanation and proof.

(7) An hypothesis is a tentative induction. As soon as it is deprived of its tentative nature it ceases to be an hypothesis.

(8) Hypothesis and theory are often used interchangeably when reference is made to phenomena of low probability. Theory should be used only in instances of high probability.

(9) A permissible hypothesis must be (1)conceivable; (2)capable of proof or disproof; (3)adequate; (4)simple; (5)must not contradict any verified truth.

(10) The hypothesis is especially serviceable in these four particulars: (1)as a working basis; (2)as a guide to ultimate truth; (3)as a discoverer of immediate truth; (4)as affording probable explanations.

(11) There are certain characteristics which an honest and courageous investigator needs to possess. These are: (1)undoubted ability as an accurate observer of facts, (2)a constructive imagination, (3)a passion for truth.

To build an acceptable hypothesis without fact is as impossible as it is to build a house without a foundation.

The genius, because of his imaginative insight, transforms the simple fact into a complex invention or law.

A prevailing “intellectual dishonesty” suggests the need of “a greater passion for truth.”

14. REVIEW QUESTIONS.

15. QUESTIONS FOR ORIGINAL THOUGHT AND INVESTIGATION.