Your Mind and How to Use It Part 9

* * * Strictly speaking, every intelligent act of the mind is accompanied with a judgment. To know is to discriminate and, therefore, to judge. Every sensation or cognition involves a knowledge and so a judgment that it exists. The mind cannot think at all without judging; to think is to judge. Even in forming the notions which judgment compares, the mind judges. Every notion or concept implies a previous act of judgment to form it; in forming a concept we compare the common attributes before we unite them, and comparison is judgment. It is thus true that 'Every concept is a contracted judgment; every judgment an expanded concept.'"

It is needless to say that as judgments lie at the base of our thinking, and also appear in every part of its higher structure, the importance of correct judgment in thought cannot be overestimated. But it is often very difficult to form correct judgment even regarding the most familiar things around us. Halleck says: "In actual life things present themselves to us with their qualities disguised or obscured by other conflicting qualities. Men had for ages seen burning substances and had formed a concept of them. A certain hard, black, stony substance had often been noticed, and a concept had been formed of it. This concept was imperfect; but it is very seldom that we meet with perfect, sharply-defined concepts in actual life. So it happened that for ages the concept of burning substance was never linked by judgment to the concept of stone coal. The combustible quality in the coal was overshadowed by its stony attributes. 'Of course stone will not burn,'

people said. One cannot tell how long the development of mankind was r.e.t.a.r.ded for that very reason. England would not to-day be manufacturing products for the rest of the world had not some one judged coal to be a combustible substance. * * * Judgment is ever silently working and comparing things that to past ages seemed dissimilar; and it is constantly abstracting and leaving out of the field of view those qualities which have simply served to obscure the point at issue."

Gordy says: "The credulity of children is proverbial; but if we get our facts at first hand, if we study 'the living, learning, playing child,'

we shall see that he is quite as remarkable for incredulity as for credulity. The explanation is simple: _He tends to believe the first suggestion that comes into his mind, no matter from what source_; and since his belief is not the result of any rational process, he cannot be made to disbelieve it in any rational way. Hence it is that he is very credulous about any matter about which he has no ideas; but let the idea once get possession of his mind, and he is quite as remarkable for incredulity as before for credulity. * * * If we study the larger child,--the man with a child's mind, an uneducated man,--we shall have the same truth forced upon us. If the beliefs of men were due to processes of reasoning, where they have not reasoned they would not believe. But do we find it so? Is it not true that the men who have the most positive opinions on the largest variety of subjects--so far as they have ever heard of them--are precisely those who have the least right to them? Socrates, we remember, was counted the wisest man in Athens because he alone resisted his natural tendency to believe in the absence of evidence; he alone would not delude himself with the conceit of knowledge without the reality; and it would scarcely be too much to say that the intellectual strength of men is in direct proportion to the number of things they are absolutely certain of. * * * I do not, of course, mean to intimate that we should have no opinions about matters that we have not personally investigated. We take, and ought to take, the opinion of some men about law, and others about medicine, and others about particular sciences, and so on. But we should clearly realize the difference between holding an opinion on trust and holding it as the result of our own investigations."

Brooks says: "It should be one of the leading objects of the culture of young people to lead them to acquire the habit of forming judgments.

They should not only be led to see things but to have opinions about things. They should be trained to see things in their relations and to put these relations into definite propositions. Their ideas of objects should be worked up into thoughts concerning the objects. Those methods of teaching are best which tend to excite a thoughtful habit of mind that notices the similitudes and diversities of objects and endeavors to read the thoughts which they embody and of which they are the symbols."

The study of logic, geometry, and the natural sciences is recommended for exercise of the faculty of judgment and the development thereof. The study and practice of even the lower branches of mathematics are also helpful in this direction. The game of checkers or chess is recommended by many authorities. Some have advocated the practice of solving enigmas, problems, rebuses, etc., as giving exercise to this faculty of the mind. The cultivation of the "Why?" att.i.tude of mind, and the answering of one's own mental questions, is also helpful, if not carried to excess. "Doubting Thomas" is not always a term of reproach in these days of scientific habits of thought, and "the man from Missouri" has many warm admirers.

CHAPTER XXIV.

Primary Laws of Thought.

In connection with this subject we herewith call the attention of the student to the well-known Primary Laws of Thought which have been recognized as valid from the time of the ancient Greek logicians. These laws are self-evident, and are uncontradictable. They are axiomatic.

Jevons says of them: "Students are seldom able to see at first their full meaning and importance. All arguments may be explained when these self-evident laws are granted; and it is not too much to say that the whole of logic will be plain to those who will constantly use these laws as their key." Here are the Three Primary Laws of Thought:--

I. _Law of Ident.i.ty._ "Whatever is, _is_."

II. _Law of Contradiction._ "Nothing can both be and not be."

III. _Law of Excluded Middle._ "Everything must either be or not be; there is no middle course."

I. The first of these laws, called "_The Law of Ident.i.ty_," informs us that a thing is always itself, no matter under what guise or form it is perceived or may present itself. An animal is always a bird if it possesses the general characteristics of a "bird," no matter whether it exhibits the minor characteristics of an eagle, a wren, a stork, or a humming bird. In the same way a whale is a mammal because it possesses the general characteristics of a mammal notwithstanding that it swims in the water like a fish. Also, sweetness is always sweetness, whether manifested in sugar, honey, flowers, or products of coal tar. If a thing _is_ that thing, then it _is_, and it cannot be logically claimed that it _is not_.

II. The second of these laws, called "_The Law of Contradiction_,"

informs us that the same quality or cla.s.s cannot be both affirmed and denied of a thing at the same time and place. A sparrow cannot be said to be both "bird" and "not bird" at the same time. Neither can sugar be said to be "sweet" and "not sweet" at the same time. A piece of iron may be "hot" at one end and "not hot" at another, but it cannot be both "hot" and "not hot" at the same place at the same time.

III. The third of these laws, called "_The Law of Excluded Middle_,"

informs us that a given quality or cla.s.s _must_ be affirmed or denied to _everything_ at any given time and place. Everything either must be of a certain cla.s.s or not, must possess a certain quality or not, at a given time or place. There is no other alternative or middle course. It is axiomatic that any statement _must_ either be or not be true of a certain other thing at any certain time and place; there is no escape from this. Anything _either_ must be "black" or "not black," a bird or not a bird, alive or not alive, at any certain time or place. There is nothing else that it can be; it cannot both be and not be at the same time and place, as we have seen; therefore, it must either be or not be that which is a.s.serted of it. The judgment must decide which alternative; but it has only two possible choices.

But the student must not confuse opposite qualities or things with "not-ness." A thing may be "black" or "not black," but it need not be white to be "not black," for blue is likewise "not black" just as it is "not white." The neglect of this fact frequently causes error. We must always affirm either the existence or non-existence of a quality in a thing; but this is far different from affirming or denying the existence of the opposite quality. Thus a thing may be "not hard" and yet it does not follow that it is "soft"; it may be _neither_ hard nor soft.

FALLACIOUS APPLICATION.

There exists what are known as "fallacies" of application of these primary laws. A fallacy is an unsound argument or conclusion. For instance, because a particular man is found to be a liar, it is fallacious to a.s.sume that "_all_ men are liars," for lying is a particular quality of the individual man, and not a general quality of the family of men. In the same way because a stork has long legs and a long bill, it does not follow that all birds must have these characteristics simply because the stork is a bird. _It is fallacious to extend an individual quality to a cla.s.s._ But it is sound judgment to a.s.sume that a cla.s.s quality must be possessed by all individuals in that cla.s.s. It is a far different proposition which a.s.serts that "_some_ birds are black," from that which a.s.serts that "_all_ birds are black."

The same rule, of course, is true regarding negative propositions.

Another fallacy is that which a.s.sumes that because the affirmative or negative proposition has not been, or cannot be, proved, it follows that the opposite proposition must be true. The true judgment is simply "not proven."

Another fallacious judgment is that which is based on attributing absolute quality to that which is but relative or comparative. For instance, the terms "hot" and "cold" are relative and comparative, and simply denote one's relative opinion regarding a fixed and certain degree of temperature. The _certain_ thing is the degree of temperature, say 75 degrees Fahrenheit; of this we may logically claim that it _is_ or _is not_ true at a certain time or place. It either _is_ 75 degrees Fahrenheit or it _is not_. But to one man this may seem _warm_ and to another _cold_; both are right in their judgments, so far as their own relative feelings are concerned. But neither can claim absolutely that it is _warm_ or _cold_. Therefore, it is a fallacy to ascribe absolute quality to a relative one. The _absolute fact_ comes under the Law of Excluded Middle, but a personal opinion is not an absolute fact.

There are other fallacies which will be considered in other chapters of this book, under their appropriate heading.

CHAPTER XXV.

Reasoning.

Reasoning, the third great step in thinking, may be said to consist of ascertaining new truths from old ones, new judgments from old ones, unknown facts from known ones; in short, of proceeding logically from the known to the unknown, using the known as the foundation for the unknown which is sought to be known. Gordy gives us the following excellent definition of the term: "Reasoning is the act of going from the known to the unknown through other beliefs; of basing judgment upon judgments; reaching beliefs through beliefs." Reasoning, then, is seen to be a process of building a structure of judgments, one resting upon the other, the topmost point being the final judgment, but the whole const.i.tuting an edifice of judgment. This may be seen more clearly when the various forms of reasoning are considered.

IMMEDIATE REASONING.

The simplest form of reasoning is that known as "immediate reasoning,"

by which is meant reasoning by directly comparing two judgments without the intervention of the third judgment, which is found in the more formal cla.s.ses of reasoning. This form of reasoning depends largely upon the application of the Three Primary Laws of Thought, to which we have referred in a previous chapter.

It will be seen that _if_ (_a_) a thing is always itself, then (_b_) all that is included in it must partake of its nature. Thus, the bird family has certain cla.s.s characteristics, therefore by immediate reasoning we know that _any_ member of that family must possess those cla.s.s characteristics, whatever particular characteristics it may have in addition. And we likewise know that we cannot attribute the _particular_ characteristics, as a matter of course, to the other members of the cla.s.s. Thus, though all sparrows are birds, it is not true that all birds are sparrows. "All biscuits are bread; but all bread is not biscuit."

In the same way we know that a thing cannot be bird and mammal at the same time, for the mammals form a not-bird family. And, likewise, we know that everything _must_ be either bird or not bird, but that being not bird does not mean being a mammal, for there are many other not-bird things than mammals. In this form of reasoning distinction is always made between the _universal_ or general cla.s.s, which is expressed by the word _all_, and the _particular_ or individual, which is expressed by the word "some." Many persons fail to note this difference in their reasoning, and fallaciously reason, for instance, that because _some_ swans are white, _all_ swans must be so, which is a far different thing from reasoning that if _all_ is so and so, then _some_ must be so and so. Those who are interested in this subject are referred to some elementary text-book on logic, as the detailed consideration is too technical for consideration here.

REASONING BY a.n.a.lOGY.

Reasoning by a.n.a.logy is an elementary form of reasoning, and is the particular kind of reasoning employed by the majority of persons in ordinary thought. It is based upon the unconscious recognition by the human mind of the principle which is expressed by Jevons as: "_If two or more things resemble each other in many points, they will probably resemble each other in more points._" The same authority says: "Reasoning by a.n.a.logy differs only in degree from that kind of reasoning called '_generalization_.' When _many things_ resemble each other in a _few properties_, we argue about them by generalization. When a _few things_ resemble each other in _many properties_, it is a case of a.n.a.logy."

While this form of reason is frequently employed with more or less satisfactory results, it is always open to a large percentage of error.

Thus, persons have been poisoned by toadstools by reason of false a.n.a.logous reasoning that because mushrooms are edible, then toadstools, which resemble them, must also be fit for food; or, in the same way, because certain berries resemble other edible berries they must likewise be good food. As Brooks says: "To infer that because John Smith has a red nose and is also a drunkard, then Henry Jones, who also has a red nose, is also a drunkard, would be dangerous inference. Conclusions of this kind drawn from a.n.a.logy are frequently dangerous." Halleck says: "Many false a.n.a.logies are manufactured, and it is excellent thought training to expose them. The majority of people think so little that they swallow these false a.n.a.logies just as newly-fledged robins swallow small stones dropped into their mouths."

Jevons, one of the best authorities on the subject, says: "There is no way in which we can really a.s.sure ourselves that we are arguing safely by a.n.a.logy. The only rule that can be given is this: That the more closely two things resemble each other, the more likely it is that they are the same in other respects, especially in points closely connected with those observed. In order to be clear about our conclusions, we ought, in fact, never to rest satisfied with mere a.n.a.logy, but ought to try to discover the general laws governing the case. * * * We find that reasoning by a.n.a.logy is not to be depended upon, unless we make such an inquiry into the causes and laws of the things in question that we really employ inductive and deductive reasoning."

HIGHER FORMS OF REASONING.

The two higher forms of reasoning are known, respectively, as (1) inductive reasoning, or inference from particular facts to general laws; and (2) deductive reasoning, or inference from general truths to particular truths. While the cla.s.s distinction is made for the purpose of clear consideration, it must not be forgotten that the two forms of reasoning are generally found in combination. Thus, in inductive reasoning many steps are taken by the aid of deductive reasoning; and, likewise, before we can reason deductively from general truths to particular ones we must have discovered the general truths by inductive reasoning from particular facts. Thus there is a unity in all reasoning processes as there is in all mental operations. Inductive reasoning is a _synthetical_ process; deductive reasoning, an _a.n.a.lytical_ one. In the first we combine and build up, in the latter we dissect and separate.

CHAPTER XXVI.

Inductive Reasoning.

Inductive reasoning is based upon the axiom: "_What is true of the many is true of the whole._" This axiom is based upon man's belief in the uniformity of nature. Inductive reasoning is a mental ladder by which we climb from particular facts to general laws, but the ladder rests upon the belief that the universe is governed by law.

The steps in inductive reasoning are as follows:--

I. Observation, investigation, and examination of particular facts or things. If we wish to know the general characteristics of the bird family, we must first examine a sufficient number of birds of many kinds so as to discover the comparatively few general characteristics possessed by _all_ of the bird family, as distinct from the particular characteristics possessed by only _some_ of that family. The greater the number of individuals examined, the narrower becomes our list of the general qualities common to _all_. In the same way we must examine many kinds of flowers before we come to the few general qualities common to all flowers, which we combine in the general concept of "flower." The same, of course, is true regarding the discovery of general laws from particular facts. We examine the facts and then work toward a general law which will explain them. For instance, the Law of Gravitation was discovered by the observation and investigation of the fact that all objects are attracted to the earth; further investigation revealed the fact that all material objects are attracted to each other; then the general law was discovered, or, rather, the hypothesis was advanced, was found to explain the facts, and was verified by further experiments and observation.