IN issuing this new edition of my Principles of Logic I welcome the opportunity it affords me of expressing my thanks to my various critics for the very kind manner in which the work was received. The friendly notices accorded to it, not only by such as were in sympathy with its general standpoint, but by those whose philo Sophical position was altogether different, tend to show that at the present time a new interest is felt in that Scholastic system, whose principles it was my purpose to defend.