In his "Game of Logic" Lewis Carroll introduced an original method of working logical problems by means of diagrams; this method he superseded in after years for a much simpler one the method of "Subscripts."
In "Symbolic Logic, Part i." (London: Macmillan, 1896) he employed both methods. The Introduction is specially addressed "to Learners," whom Lewis Carroll advises to read the book straight through, without dipping.
This Rule [he says] is very desirable with other kinds of books—such as novels, for instance, where you may easily spoil much of the enjoyment you would otherwise get from the story by dipping into it further on, so that what the author meant to be a pleasant surprise comes to you as a matter of course. Some people, I know, make a practice of looking into vol. iii. first, just to see how the story ends; and perhaps it is as well just to know that all ends happily—that the much-persecuted lovers do marry after all, that he is proved to be quite innocent of the murder, that the wicked cousin is completely foiled in his plot, and gets the punishment he deserves, and that the rich uncle in India {Qu. Why in India?Ans. Because, somehow, uncles never can get rich anywhere else) dies at exactly the right moment—before taking the trouble to read vol i. This, I say, is just permissible with a novel, where vol. iii. has a meaning, even for those who have not read the earlier part of the story; but with a scientific book, it is sheer insanity. You will find the latter part hopelessly unintelligible, if you read it before reaching it in regular course.
