know. Then read the broad surveys and digests of the subject which appear in the encyclopedias, in such monthly magazines as the American Review of Reviews and the World's Work, and in such weekly periodicals as the Nation, the Independent, the Outlook, and the Literary Digest. Thus you will get some idea of the origin and history of the controversy, of the latest information, of the main contentions on both sides, and of the leading authorities.

Magazines are valuable sources of material on current topics. The best indexes to Periodical Literature are the Reader's Guide, published monthly, and Poole's Index and The Annual Library Index. These and the card catalogues should be used first. In consulting such lists, the investigator should look for material under several heads. If, for instance, he seeks information on the question whether intercollegiate athletics should be abolished, he should not expect to find all the significant articles indexed under "Athletics." He may find important contributions to the controversy under such heads as "University," "College," "School," "Baser ball," "Football," "Physical Culture," and "Education." He should continue his search until he has an extensive list of references from which to choose. Otherwise, he may spend too much time in reading inferior articles, while he either overlooks the best ones, or discovers them when it is too late to give them due attention.

Special lists of selected books and articles are published frequently by the Library of Congress on such prominent subjects as Child Labor, Employer's Liability, Taxation of Inheritances and of Incomes, and Tariffs of Foreign Countries. A book by R. C. Ringwalt, called Briefs on Public Questions (Longmans, Green & Co.),

contains suggestive briefs on twenty-five of the most important public questions of the day, together with selected lists of references. The Encyclopedia of Social Reform, by W. D. P. Bliss, is another storehouse of information on debatable topics. Still another useful book is Henry Matson's References for Literary Workers (A. C. McClurg & Co.). It contains a list of over six hundred questions for discussion. Although most of these are unsuitable for debate, there are well-selected references on various debatable propositions relating to such subjects as Party Government, Negro Suffrage, State Rights, The Jury, Capital Punishment, Divorce Laws, Immigration, Railroads, Prohibition, Protection, Income Tax, Trade Unions, Trusts. The references from this book should in every case be supplemented by references from the latest magazine and congressional indexes.

There are many official publications which furnish information regarding the most perplexing public problems. The government of the United States, the government of each state, many municipalities, many reform associations, religious bodies, industrial boards, and other organizations promoting special interests, employ in the aggregate thousands of experts to investigate particular problems, to compile the laws, to collect, tabulate, and interpret statistics, and to suggest remedies for alleged evils. The reports of these experts are widely distributed. Most of the United States Government reports are deposited in every college library in the country. To mention only a few, there are the Census reports, the annual reports of the Commissioner of Education and of the Interstate Commerce Commission, the Messages of the Presidents, and the Congressional Record.

The Congressional Record is indexed under three heads-names, subjects, and bills by their official numbers. For each session of Congress, the Documents are arranged in six groups: Senate Executive Documents, Senate Miscellaneous, Senate Reports (of committees), House Executive Documents, House Miscellaneous, House Reports (of committees). There is a Document Index for each session of Congress. The Monthly Catalogue, which lists all the publications of the United States, is the best source of information on recent government publications. At the close of each Congress, a catalogue is published listing and describing all the publications of that Congress. Both the catalogue and the documents therein listed can be obtained by almost any school or public library on application to the Superintendent of Documents. There is a valuable Index of Economic Material in Documents of the States of the United States, published by the Carnegie Institution of Washington. Then there are the publications of societies with a purpose, such as the Report of the National Civic Federation on Municipal and Private Operation of Public Utilities (1907), the proceedings of the Annual Conventions of the National Education Association, and the publications of the Congo Reform Association.

Valuable special references are often appended to the articles in the best encyclopedias. A convenient list of references is given in the introduction, by A. B. Hart, to Brooking's and Ringwalt's Briefs for Debate (Longmans, Green & Co.). This enumerates the most fruitful sources of information, finding-lists, indexes, books on debating, and compilations for current events. The briefs in this book, though they should never be followed as models, offer some suggestions; and the refer

ences to each brief, though not up-to-date, may be supplemented by later material.

On industrial questions the Report of the United States Industrial Commission (nineteen volumes, 19001902) contains a mass of valuable material; likewise the Selections and Documents in Economics edited by Professor W. Z. Ripley, of Harvard University (Ginn & Co.). On mooted political questions R. C. Ringwalt is editing a series of volumes entitled American Public Questions (Henry Holt & Co.). Putnam's Questions of the Day also contains a number of volumes treating of debatable subjects. Plans are nearly completed (June, 1908) for the publication of a quarterly periodical to be devoted entirely to debating. This periodical will contain complete reports of debates and valuable bibliographies on current questions.

A whole volume of suggestions might easily be furnished to the beginner in the search for materials; but, after all, no instruction in this matter can equal his own experience. He will learn how to economize time partly by wasting time, and he will feel the resources of libraries at his command only after extensive investigation and research of his own.

FOURTH CHAPTER

PROVING THE PROPOSITION: INDUCTIVE AND

DEDUCTIVE ARGUMENT

"All inference, consequently all proof, and all discovery of truths not self-evident, consists of inductions, and the interpretations of inductions; all our knowledge, not intuitive, comes to us exclusively from that source. MILL.

Ar the outset of our investigation concerning the kinds of argument, we find a classification provided by the science of logic-inductive argument and deductive argument. But before we consider that classification, we shall do well to determine the relation between argumentation and logic.

RELATION OF ARGUMENTATION AND LOGIC Argumentation, in common with every other art, presupposes scientific knowledge. It may be called the art of which logic is the science. Logic tests our thinking-processes to determine whether they conform to fixed rules. That is to say, the main purpose of logic is to enable men to distinguish between good and bad reasoning. The communication of reasoning to other people for the purpose of convincing them and urging them to action is argumentation. This suggests a point of view which must be maintained throughout the study and practice of argumentation, for the final test of any piece of evidence — a definition, a citation from authority, an inference is never its sufficiency for the one who employs it, but its sufficiency for those to whom it