PREFACE. THE OBJECT of the following treatise is to describe the nature of original Scientific Research, the chief personal conditions of success in its pursuit, the general methods by which discoveries are made in Physics and Chemistry, and the causes of failure; and thus to elucidate, so far as possible, the special mental conditions and processes by means of which the mind of man ascends from the known to the unknown in matters of science. Some of the conditions described are such as I have in my own experience found to be necessary, and some of the methods are those I have frequently employed in my own researches. Many young scientific men hesitate to undertake original research from a fear of the great difficulty of the task, and of repeating experiments which others have already made, and also because they do not know how to select suitable subjects; and, as one of the most effectual preliminary conditions of ensuring success in research is a thorough study of the general and special methods and conditions of discovery, it is hoped that such persons will be induced to attempt original investigation by the aid of the suggestions contained in this book. Although men have during all modern time made discoveries in Physics and Chemistry, and many eminent investigators have occupied and are still occupying a large portion of their lives in original scientific research, the conditions of success and failure in the pursuit of original scientific inquiry, and the methods employed in making discoveries, remain for the most part unknown to ordinary persons. In nearly all cases investigators, from some cause or other, have not troubled themselves to describe the actual circumstances which gave rise to their discoveries, and have thus failed to leave behind them the ladder by which they ascended, and by which others might, to some extent at least, have been assisted in the pursuit of similar objects. Faraday, and particularly Kepler, did, however, leave an account of a few of the failures as well as the successes of their researches. The biographies of such men, and also some other books, such as Thomson's Histories of Chemistry and of the Royal Society; Whewell's "History of the Inductive Sciences,' and his Philosophy of those sciences; Archbishop Thomson's Laws of Thought;' Sir John Herschel's Discourse on Natural Philosophy;' Jevons's Principles of Science ;' Buckley's 'Short History of Natural Science,' and a few other books, contain, in fragmentary portions, a large amount of information of great value to an original scientific investigator. The object of the present treatise, however, is different. It is to describe in a concise form the general course of pro 6 cedure and the various methods, by pursuing which, a real student of science, possessing a certain amount of scientific knowledge, a disciplined mind, and manipulative skill, may reasonably expect to succeed in finding new truths of nature. It has been said that Lord Bacon hoped to furnish a method of scientific investigation which should be so complete and accurate as to constitute an organ of discovery, and reduce all intellects to a level, making success in the search after truth a matter merely of time and labour, and that his followers, taught by experience that discoveries cannot thus be made by rule, have attempted merely to analyse and describe the process by which discoveries have been made, without hoping to indicate any sure method of adding to their number.' Whilst I do not forget Dr. Whewell's assertion that, speaking with strictness, an Art of Discovery is not possible; that we can give no rules for the pursuit of truth which shall be universally and peremptorily applicable; and that the helps which we can offer to the inquirer in such cases are limited and precarious, I share his hope that aids may be pointed out which are neither worthless. nor uninstructive.2 I have no wish even to suggest the idea of reducing all intellects to a level, nor to make success in research a 1 Bowen's Logic, 8th edit. p. 403. In a short conversation on this subject which I once had with the late Mr. Faraday he expressed to me a more favourable opinion of the possibility of my proposition of framing an Art of Scientific Discovery than is contained in this extract. 2 Philosophy of the Inductive Sciences, vol. ii. p. 483. matter merely of time and labour only, nor to pretend that important discoveries can be completely made by rule alone. My purpose is only to show that an art of scientific discovery is much more possible now than it was in the time of Lord Bacon, and is fast becoming more so, and that the process of scientific discovery can even now be much more completely reduced to order and rule than is usually supposed. The process of scientific discovery depends on a combination of experiment and logical inference; and the small success of previous writers respecting it has, in my opinion, been due to the circumstance, that those who possessed both the experimental and the logical knowledge necessary, made no sufficiently persistent attempt to determine how far the work of scientific discovery may be reduced to an art. To some the very proposal to write a book on such a subject may appear presumptuous; and even among scientific investigators there are those who consider that the methods of discovery are incommunicable. But original scientific research is not a supernatural operation. If it were, it would not be possible to make discoveries by means of our natural faculties, nor to communicate them by ordinary means. It is a natural process, and, being such, it must have laws according to which it operates. It is effected by means of our mental powers, and is therefore subject to the rules of mental action, and is communicable by ordinary natural methods. It is also being reduced, as knowledge advances, to rules of action, and will in time become one of the noblest of all intellectual em |