3. Finally, if I were Dr. Nansen and proposed to you to join my North Pole expedition, your option would be momentous; for this would probably be your only similar opportunity, and your choice now would either exclude you from the North Pole sort of immortality altogether or put at least the chance of it into your hands. He who refuses to embrace a unique opportunity loses the prize as surely as if he tried and failed. Per contra the option is trivial when the opportunity is not unique, when the stake is insignificant, or when the decision is reversible if it later prove unwise. Such trivial options abound in the scientific life. A chemist finds an hypothesis live enough to spend a year in its verification: he believes in it to that extent. But if his experiments prove inconclusive either way, he is quit for his loss of time, no vital harm being done.

It will facilitate our discussion if we keep all these distinctions well in mind.[55][!--Note--]

In some arguments the working out of the definitions of a few principal terms may occupy much space. Matthew Arnold, a famous critic of the last generation, wrote as an introduction to a volume of selections from Wordsworth's poems an essay with the thesis that Wordsworth is, after Shakespeare and Milton, the greatest poet who has written in English; and to establish his point he laid down the definition that "poetry is at bottom a criticism of life; that the greatness of a poet lies in his powerful and beautiful application of ideas to life—to the question, How to live." To the development of this definition he gave several pages, for the success of his main argument lay in inducing his readers to accept it.

Many legal arguments are wholly concerned with establishing definitions, especially in those cases which deal with statute law. The recent decisions of the Supreme Court of the United States in the Corporation Tax cases and the Standard Oil Case are examples: in each of these what was at issue was the exact meaning of the words used in certain statutes passed by Congress. In the common law, too, there are many phrases which have come down from past centuries, the meanings of which have been defined again and again as new cases came up. We have seen (p. 63) how careful definition the word "murder" may need. "Malice aforethought" is another familiar instance: it sounds simple, but when one begins to fix the limits at which sudden anger passes over into cool and deliberate enmity, or how far gone a man must be in drink before he loses the consciousness of his purposes, even a layman can see that it has difficulties.

In such cases as these a dictionary definition would be merely a starting point. It may be a very useful starting point, however, as in the following extract from an article by Mr. E.P. Ripley, president of the Atchison, Topeka, and Santa Fe Railway Company, on "The Railroads and the People":

There is one point regarding this matter that many forget: this is that in all affairs there are two kinds of discrimination. There is the kind, which, as the dictionary expresses it, "sets apart as being different," which "distinguishes accurately," and there is the widely different kind which "treats unequally." in all ordinary affairs of life we condemn as "undiscriminating" those who have so little judgment or fairness as not to "distinguish accurately" or "set apart things that are different"—who either treat equally things that are unequal, or treat unequally things that are equal. Now, when the railway traffic manager "sets apart things that are different," and treats them differently, he simply does what it is the duty of every one to do.[56][!--Note--]

Then he goes on to develop this definition by showing the facts on which it has to bear.

On the other hand do not bore your readers with dictionary definitions of words whose meaning no one doubts; that is a waste of good paper for you, and of good time for them; and we have seen in Chapter II the futility of the dictionary for cases in which there is real disagreement over the meaning of a word.

It will be seen, then, that the analysis you have made in preparation for the brief may spread out large or small in the argument itself. It is wise, therefore, to look on the work done for the introduction to the brief as work done largely to clear up your own thought on the subject; when you come to writing out the argument itself, you can go back to the introduction to the brief, and see how much space you are now going to give it.

In a college or school argument you will usually follow it rather closely; and you do well to do so, for you will thus fix in your mind a useful model. But when you get out into the world, you will have to consider in each case the needs and prepossessions of the particular audience. Here as everywhere in the argument you must exercise judgment; there is no formula which will fit all cases. The scheme of analysis of the case which has been expounded in Chapter II has stood the test as the best means yet found of exploring a subject and insuring clarity of thought and certainty of attack;[57][!--Note--] but I know of no single fixed scheme for the argument itself which will not be racked apart by the first half dozen practical arguments you apply it to.