True, many of the holders of the beliefs above enumerated declaimed against “magic.”[46] But sometimes fear of being accused of magic was their very reason for so doing. Bede had such a fear when he treated of divination by thunder. Roger Bacon took suspicious care to insist that his theories had nothing to do with magic, which he declared was for the most part a mere pretense and could bring marvels to pass only by diabolical assistance.[47] The writer of the _Speculum Astronomiae_—probably Albertus Magnus—found it necessary to write a treatise to distinguish books of necromancy from works on “astronomy,” _i. e._, astrology.[48] Coming to a later age, we find Agrippa frankly owning his trust in magic, and including under it, in his three books of _Occult Philosophy_, practically all the beliefs that we have mentioned. For him magic embraced the fields of nature, mathematics and theology. Indeed, men of his day and of the century following displayed a tendency to stretch the term to include true science. He himself called magic “the acme of all philosophy.” Giovanni Battista della Porta (1540–1615), not it is true without considerable justification, called his encyclopedic work on nature _Natural Magic_.[49] Lord Bacon chose to understand magic “in its ancient and honorable significance” among the Persians as “a sublimer wisdom or a knowledge of universal nature.” He said that as physics, investigating efficient and material causes, produced mechanics, so metaphysics, studying into forms, produced magic.[50] Apparently, then, magic has a broad significance and a long history. The word itself takes us back to the Magi of ancient Persia; the thing it represents is older yet. It will form the theme of our next chapter, where we shall discuss its history and its meaning, and then the particular significance of those beliefs accepted by men of learning which have been enumerated in the present chapter. CHAPTER II MAGIC: ITS ORIGINS AND RELATIONS TO SCIENCE To men of the past—how long ago does not at present matter—magic meant far more than the performance for their amusement of clever tricks, which however puzzling they knew well enough were based upon illusion and deception. There was a real magic for them.