She states that further examples exist in and are crucial to Prospero’s control of the island, but she will not make an argument solely based on textual evidence from Shakespeare.
Her argument is augmented by the fact that audiences assumed that Prospero had a magical book until the twentieth century, and because substantial research has been done on the grimoires of early modern conjurors and why the population of the time believed in them.
The spirits summoned by Ariel may be classified as those of fire, air, earth, and water.
Fire is evoked in lightning and the forms taken by Ariel in flames on the poles and rigging of the ship, and the will-o-the-wisps used to torment Caliban.
The other was beneficent, derived from studies in the occult and used generally for discovery of new forces and investigation the occult and used generally for discovery of new forces and investigation into the laws of physics and other scientific research.
Examples of both types are in the play, where they form a contrast, that of the witch Sycorax, very sketchily developed, and that of Prospero, very fully developed.The quote “I’ll to my book, / For yet ere suppertime must I perform / Much business” (3.1.113-115) is the foundation which validates her argument and interests her audience.It acknowledges that spirit magic has an obvious existence in the book, being his ‘business’ and connects it to his book.Sycorax was allied with the devil, who gave her power over the air with its invisibility and swiftness of motion, but her evil work resulted in her banishment and death.Prospero invoked only his own mental intelligence to win greater powers.Before he was sufficiently learned his lack of wisdom indirectly led to banishment, but afterwards he had full control over the air and greater prowess.He used them only for good, his own restoration to the throne, the welfare of his daughter, the repentance of Alonso, and punishment for the disobedient.After describing the content of these two books she discusses the populations attitude towards them.She then sets up the relation of the grimoires she’s studied to Shakespeare’s play.Mowat concludes with reiterations of the points she’s made throughout her essay, but not asserting much, outside of the existence of the book.She leaves the reader with and open ended statement acknowledging that many of the questions she’s raised in her essay will remain unanswered until more is learned about ancient grimoires.