It is true that inventis aliquid addere facile est, therefore a man, after having studied the principles of his subject, will have to make himself acquainted with the more recent information written upon it.  In general, the following rule holds good here as elsewhere, namely:  what is new is seldom good; because a good thing is only new for a short time.

What the address is to a letter the title should be to a book—­that is, its immediate aim should be to bring the book to that part of the public that will be interested in its contents.  Therefore, the title should be effective, and since it is essentially short, it should be concise, laconic, pregnant, and if possible express the contents in a word.  Therefore a title that is prolix, or means nothing at all, or that is indirect or ambiguous, is bad; so is one that is false and misleading:  this last may prepare for the book the same fate as that which awaits a wrongly addressed letter.  The worst titles are those that are stolen, such titles that is to say that other books already bear; for in the first place they are a plagiarism, and in the second a most convincing proof of an absolute want of originality.  A man who has not enough originality to think out a new title for his book will be much less capable of giving it new contents.  Akin to these are those titles which have been imitated, in other words, half stolen; for instance, a long time after I had written “On Will in Nature,” Oersted wrote “On Mind in Nature.”

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A book can never be anything more than the impression of its author’s thoughts.  The value of these thoughts lies either in the matter about which he has thought, or in the form in which he develops his matter—­that is to say, what he has thought about it.

The matter of books is very various, as also are the merits conferred on books on account of their matter.  All matter that is the outcome of experience, in other words everything that is founded on fact, whether it be historical or physical, taken by itself and in its widest sense, is included in the term matter.  It is the motif that gives its peculiar character to the book, so that a book can be important whoever the author may have been; while with form the peculiar character of a book rests with the author of it.  The subjects may be of such a nature as to be accessible and well known to everybody; but the form in which they are expounded, what has been thought about them, gives the book its value, and this depends upon the author.  Therefore if a book, from this point of view, is excellent and without a rival, so also is its author.  From this it follows that the merit of a writer worth reading is all the greater the less he is dependent on matter—­and the better known and worn out this matter, the greater will be his merit.  The three great Grecian tragedians, for instance, all worked at the same subject.