Thus it is clear that if there were not in man a power different from any of those of the animals, the latter would be superior to man in inventions and the comprehension of realities. Therefore, it is evident that man has a gift which the animal does not possess. Now, the animal perceives sensible things but does not perceive intellectual realities. For example, that which is within the range of its vision the animal sees, but that which is beyond the range of sight it is not possible for it to perceive, and it cannot imagine it. So it is not possible for the animal to understand that the earth has the form of a globe. But man from known things proves unknown things and discovers unknown truths. For example, man sees the curve of the horizon, and from this he infers the roundness of the earth. The Pole Star at ‘Akká, for instance, is at 33°—that is to say, it is 33° above the horizon. When a man goes toward the North Pole, the Pole Star rises one degree above the horizon for each degree of distance that he travels—that is to say, the altitude of the Pole Star will be 34°, then 40°, then 50°, then 60°, then 70°. If he reaches the North Pole the altitude of the Pole Star will be 90° or have attained the zenith—that is to say, will be directly overhead. This Pole Star and its ascension are sensible things. The further one goes toward the Pole, the higher the Pole