Now there is a traditional correspondence, which modern experiment has shown to be fairly reliable. There is a certain natural connexion between certain letters, words, numbers, gestures, shapes, perfumes and so on, so that any idea or (as we might call it) “spirit”, may be composed or called forth by the use of those things which are harmonious with it, and express particular parts of its nature. These correspondences have been elaborately mapped in the Book 777 in a very convenient and compendious form. It will be necessary for the student to make a careful study of this book in connexion with some actual rituals of Magick, for example, that of the evocation of Taphtatharath printed in The Equinox I, III, pages 170-190, where he will see exactly why these things are to be used. Of course, as the student advances in knowledge by experience he will find a progressive subtlety in the magical universe corresponding to his own; for let it be said yet again! not only is his aura a magical mirror of the universe, but the universe is a magical mirror of his aura.