INVENTION DEFINED. 311 CHAPTER I. NATURE OF INVENTION, AND SOME GENERAL RULES. 1. Definition.-INVENTION in Rhetoric is, primarily, the process by which an author obtains the material to be used, and devises and perfects the forms which he will employ to accomplish his purpose. Invention, secondarily, teaches how to choose subjects upon which to speak or write, how to gather material, and how to execute his purposes with it. 2. Mill's Description of Invention. John Stuart Mill, in his excellent work on Logic,* states the truth on this subject forcibly, so far as it applies to Induction. The same principle applies to all Invention. ‘Invention, though it can be cultivated, can not be reduced to rule; there is no science which will enable a man to bethink himself of that which will suit his purpose. But when he has thought of something, science will tell him whether that which he has thought of will suit his purpose or not." We may add here, that there is no science which will teach a man how to form a purpose. He must have that spontaneously, or growing out of circumstances which may be to prove a truth, to disseminate a doctrine, to produce a conviction, to lead to or prevent some action, or to amuse, etc. But when the purpose is formed, and what will suit his purpose is *Vol. i. p. 311 (London, 1856). suggested to his mind, both may be matured and perfected by science. Mr. Mill adds: “The inquirer or arguer must be guided by his own knowledge and sagacity in the choice of his inductions out of which he will construct his argument. But the validity of the argument, when constructed, depends on principles, and must be tried by tests which are the same for all inquiries." According to the same principle we may add, that the propriety of using any figure of speech, any particular mode of composition, must be decided, consciously or unconsciously, properly or improperly, by the laws of Rhetoric. 3. Rules can not exhaust the Subject.—It is plainly impossible to lay down rules upon this subject that shall embrace it entirely, for genius is ever striking out new paths. On this account, probably, many treatises on Rhetoric omit the subject of Invention entirely, and others make no attempt to present what can be of any practical value. We present a few general rules which should guide in Invention. 4. The First Rule.-The writer or speaker should in all cases, before proceeding to his work, form a definite idea of what he intends to accomplish. It may be that his circumstances already give him a specific purpose. Is he called upon to defend a certain proposition, to advocate a certain project, to describe a certain object, or to accomplish any other specific end? His powers of invention will at once be aroused and directed by that act. If he has no definite end in view except simply to write an article or make an address, then his first purpose must be arbitrarily to choose a theme. Let him decide what object he will determine to accomplish, whether to instruct, to encourage, to dissuade, or to amuse, or perhaps several of these. Then let him choose a theme. Having chosen a theme, let him adhere to it and accomplish his purpose. The worst habit for a speaker or writer to form, is the habit of retreating from tasks once entered upon. There is no conceivable theme upon which a good article may not be written. The choice of a subject for a special purpose may indeed be faulty, and if so should be changed; at the same time more depends on the genius, study, and industry of the author, than upon the theme. 5. The Second Rule. Having determined in what general form the subject shall be discussed-whether to describe something, or to prove something, or to rebut some falsehood, or simply to please—the writer should collect information, and thoughts, and facts, and illustrations bearing on the subject. Some authors commit to writing these collections and preparations, made previous to the main work. Others simply impress them on the memory. Either practice may be carried to an extreme. If writing is solely relied upon, the memory is not duly strengthened; while, on the other hand, the pen, properly used, is the most efficient aid of the memory. 6. What Use to make of the Works of others, and Plagiarism. It is often a matter of difficulty to a young writer to determine whether or not he should read the productions of others on the subject which he proposes |