II. _Philo of Alexandria and Allegorical Interpretation_: Question as to connection of allegorical interpretation with magic 72 Historical importance of allegorical interpretation and of Philo 73 Nature of Philo’s allegorical interpretation 73 His influence in the Middle Ages 75 III. _Seneca’s Problems of Nature and Divination_: Scientific traits of Seneca 75 His tendency to be esoteric and mystical 76 Ground covered by his book 77 His partial rejection of magic 77 His acceptance of divination 78 His discussion of divination from thunder 79 IV. _Ptolemy’s Tetrabiblos and Astrology_: An illustration of the astrology of the scientist 80 Ptolemy and his influence 80 Scientific tone of the preliminary remarks in the _Tetrabiblos_ 81 An attempt to base astrology upon natural law 82 Ptolemy’s explanation of the influence of the planets 82 Summary of remaining contents of his first book 83 Contents of the other three books 83 V. _The Hermetic Books and Occultism_: Their nature and history, legendary and actual 84 Their contents 86 Their importance 87 CHAPTER VI CRITICS OF MAGIC Review of the usual attitude towards magic in the Roman Empire 88 I. _Opponents of Astrology_: Cicero, Favorinus and Sextus Empiricus 89 Considerations which discount their scepticism 89 Inadequacy of their arguments 90 Astrology attacked as being impracticable 91 General problem of sidereal influence left untouched 92