Note 10 — Chapter II · THE METAPHYSICAL CRITERION AND THE METAPHYSICAL METHOD

See Bosanquet, Essentials of Logic, Lect. 8. As an illustration we may take an extreme case: “The Jabberwock was not killed yesterday.” What is the ground of this denial? At first sight it appears to be merely negative, “there are no such things as Jabberwocks to kill.” But before I can say “there are no such things as Jabberwocks” with confidence, I must have enough positive information about the structure and habits of animals to be aware that the qualities ascribed to the Jabberwock conflict with the laws of animal life. Or, if I deny the existence of Jabberwocks simply on the ground that I have never come across a specimen, this involves a positive judgment as to the relation between the animal world and the part of it I have examined, such as, “if there were Jabberwocks, I should have come across one”; or, “my acquaintance with the varieties of animals is sufficiently exhaustive to afford ground for a valid generalisation.” The fact that symbolic Logic finds it convenient to treat the universal affirmative as a double negative must not mislead us as to its actual priority in thought.