As different as the significance of the employment of this designation of a science or art among the ancients may have been, one can still infer from their actual use of it that among them it was nothing other than the logic of illusion a sophistical art for giving to its ignorance, in deed even to its intentional tricks, the air of truth, by imitating the method of thoroughness, which logic prescribes in general, and using its topics for the embellishment of every empty pretension.