The psychological doctrine of the doctors and other canonized authors who have treated scientifically of the nature of mystic contemplation, is not, however, placed above all critical discussion. A few important questions excepted, upon which the supreme authority of the Holy See has pronounced a judgment, the theory of cognition is an open area of discussion, and therefore explanations of the phenomena of the spiritual life, given by any author in accordance with his own philosophical system, may be criticised by those who differ from him in opinion. Those who follow strictly the psychology of St. Thomas, as contained in modern writers of the later Thomistic school, may easily be led by their philosophical opinions to suspect and qualify as scientifically untenable the common language of mystical writers. The passage quoted from Father Baker at the head of this article will furnish an illustration of our meaning. Those who are familiar with metaphysics will understand at once where the apparent opposition between scholastic psychology and mystical theology is found. For others it may suffice to explain that, in the metaphysics of the Thomists, no origin of ideas is recognized except that which is called abstraction from the sensible object, and that the precise difference of the human mind in respect to the angelic intellect is that the former is naturally turned to the intelligible in a sensible phantasm or image, whereas the latter is turned to the purely intelligible itself. Now, as soon as one begins to speak of a mode of contemplation similar to that of the angels――a contemplation of God and divine things without the intervention of images――he passes beyond the known domain of metaphysics, and appears to be waving his wings for a flight in the air, instead of quietly pacing the ground with the peripatetics.