Note Footnote 6: — INTRODUCTION.

The uses of Aristotle's logical treatises remained when the fashion that had called them forth had passed.6 Clear and consistent thinking, a mastery of the perplexities and ambiguities of language, power to detect identity of meaning under difference of expression, a ready apprehension of all that a proposition implies, all that may be educed or deduced from it—whatever helps to these ends must be of perpetual use. "To purge the understanding of those errors which lie in the confusion and perplexities of an inconsequent thinking," is a modern description of the main scope of Logic.7 It is a good description of the branch of Logic that keeps closest to the Aristotelian tradition.