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 existence, and as having contained the germs, not only of all other things, but even of Reason itself, so that out of Matter Reason was developed. According to Aristotle, it is impossible to conceive Matter at all as actually existing, far less as the one independent antecedent cause of all things; and it is equally impossible to think of Reason as non-existent, or as having had a late and derivative origin.

Subsidiary to his theory of knowledge, Aristotle discourses at some length, both in his treatise ‘On the Soul’ and in his ‘Physiological Tracts,’ on the Five Senses. He affirms that the sentient soul of man is able to discriminate between the properties of things, “because it is itself a mean or middle term between the two sensible extremes of which it takes cognisance,—hot and cold, hard and soft, wet and dry, white and black, acute and grave, bitter and sweet, light and darkness, &c. We feel no sensation at all when the object touched is exactly of the same temperature with ourselves, neither hotter nor colder.” This doctrine, which is obviously true, points to the relativity of the qualities of things; it shows that all qualities—e.g., “great” and “small,” and all the rest—are named from the human stand-point, and that, in short, “Man is the measure of all things.” Protagoras, indeed, had used this dictum in order to throw doubt on all knowledge and truth, for he said that everything was relative to the individual percipient, and that what