A somewhat different kind of question of fact, and one often extremely difficult to settle, is that which concerns not a single, uncomplicated fact, but a broad condition of affairs. Examples of such questions are whether woman suffrage has improved political conditions in Colorado and other states, whether the introduction of manual training in a certain high school has improved the intelligence and serviceableness of its graduates, whether political corruption is decreasing in American cities. The difficulty that faces an argument in such cases as these is not the loss of the evidence, but rather that it consists of a multitude of little facts, and that the selection of these details is singularly subject to bias and partisan feeling. These questions of a broad state of affairs are like questions of policy in that in the end their settlement depends thus largely on temperamental and practical prepossessions.
Still another and very important variety of arguments of fact, which are often conveniently described as arguments of theory, includes large scientific questions, such, for example, as the origin of our present species of plants and animals, or the ultimate constitution of matter, or the cause of yellow fever. In such arguments we start out with many facts, already gained through observation and experiment, which need the assumption of some other fact or facts attained through reasoning from the others, to make them fit together into a coherent and intelligible system. Every important new discovery in science makes necessary arguments of this sort. When the minute forms of life that the layman lumps together under the name "germs" were discovered there was a host of arguments to explain their manner of life and the way some of them cause disease and others carry on functions beneficent to mankind. A notable example of the arguments concerning this kind of fact is that at page 251 concerning the cause of yellow fever; and another is Huxley's argument on evolution (p. 233), where he points out that "the question is a question of historical fact." The element of uncertainty in the settlement of such questions is due to the facts being too large or too minute for human observation, or to their ranging through great ages of time so that we must be contented with overwhelming probability rather than with absolute proof. Furthermore the facts that are established in arguments of this sort may have to be modified by new discoveries: for many generations it was held to be a fact that malaria was caused by a miasma; now we know that it is caused by a germ, which is carried by mosquitoes. Arguments of this type tend to go through a curious cycle: they begin their life as arguments, recognized as such; then becoming the accepted explanation of the facts which are known, for a longer or shorter time they flourish as statements of the truth; and then with the uncovering of new facts they crumble away or are transformed into new and larger theories. Darwin's great theory of the origin of species has passed through two of these stages. He spoke of it as an argument, and for a few years it was assailed with fierce counterarguments; we now hold it to be a masterful explanation of an enormous body of facts. When it will pass on to the next stage we cannot foresee; but chemists and physicists darkly hint at the possibility of the evolution of inorganic as well as organic substances.
In arguments of fact, it will be noticed, there is little or no element of persuasion, for we deal with such matters almost wholly through our understanding and reason. Huxley, in his argument on evolution, which was addressed to a popular audience, was careful to choose examples that would be familiar; but his treatment of the subject was strictly expository in tone. In some arguments of this sort, which touch on the great forces of the universe and on the nature of the world of life of which we are an infinitesimal part, the tone of the discourse will take on warmth and eloquence; just as Webster in the White Murder Case, dealing with an issue of life and death, let the natural eloquence which always smoldered in his speech, burn up into a clear glow. But both Huxley and Webster would have held any studied appeal to emotion to be an impertinence.
In ordinary life most of us make fewer arguments of fact than of policy. It is only a small minority of our young men who become lawyers, and of them many do not practice before juries. Nor do any large number of men become scholars or men of science or public men, who have to deal with questions of historical fact or to make arguments of fact on large states of affairs. On the other hand, all of us have to weigh and estimate arguments of fact pretty constantly. Sooner or later most men serve on juries; and all students have to read historical and economical arguments. We shall therefore give some space in Chapter III to considering the principles of reasoning by which we arrive at and test conclusions as to the existence of facts, and the truth of assertions about them.
9. Arguments of Policy. When we turn from arguments of fact to arguments of policy it will be noticed that there is a change in the phraseology that we use: we no longer say that the assertions we maintain or meet are true or not true, but that the proposals are right or expedient or wrong or inexpedient; for now we are talking about what should or should not be done. We say, naturally and correctly, that it is or is not true that woman suffrage has improved political conditions in Colorado but it would be a misuse of words to say that it is true or not true that woman suffrage should be adopted in Ohio; and still more so to use the word "false," which has an inseparable tinge of moral obliquity. In questions of policy that turn on expediency, and in some, as we shall see directly, that turn on moral issues, we know beforehand that in the end some men who know the subject as well as we do and whose judgment is as good and whose standards are as high, will still disagree. There are certain large temperamental lines which have always divided mankind: some men are born conservative minded, some radical minded: the former must needs find things as they are on the whole good, the latter must needs see vividly how they can be improved. To the scientific temperament the artistic temperament is unstable and irrational, as the former is dry and ungenerous to the latter. Such broad and recognized types, with a few others like them, ramify into a multitude of ephemeral parties and classes—racial, political, social, literary, scholarly—and most of the arguments in the world can be followed back to these essential and irremovable differences of character. Individual practical questions, however, cross and recross these lines, and in such cases arguments have much practical effect in crystallizing opinion and judgment; for in a complicated case it is often extremely hard to see the real bearing of a proposed policy, and a good argument comes as a guide from the gods to the puzzled and wavering. But though to be effective in practical affairs one has to be positive, yet that is not saying that one must believe that the other side are fools or knaves. Some such confusion of thought in the minds of some reformers, both eminent and obscure, accounts for the wake of bitterness which often follows the progress of reform. Modesty and toleration are as important as positiveness to the man who is to make a mark in the world.
Arguments of policy are of endless variety, for we are all of us making them all the time, from the morning hour in which we argue with ourselves, so often ineffectually, that we really ought to get up when the clock strikes, to the arguments about choosing a profession or helping to start a movement for universal peace. It would be a weariness to the flesh to attempt a classification of them that should pretend to be exhaustive; but there are certain major groups of human motive which will be a good basis for a rough, but convenient, sorting out of the commoner kinds of arguments of policy. In practical affairs we ask first if there is any principle of right or wrong involved, then what is best for the practical interests of ourselves and other people, and in a few cases, when these other considerations are irrelevant, what course is dictated by our ideas of fitness and beauty. I will briefly discuss a few of the main types of the argument of policy, grouping them according as they appeal chiefly to the sense of right and wrong, to practical interests,