The Ars Notoria is a mediaeval grimoire, or magician's manual, which was widely distributed and very popular in the 13th-16th century, but virtually unknown today. It is however still very relevant in the 21st century because it contains detailed techniques to enable the practitioner to absorb whole subjects very rapidly, and to understand very complex subjects on first reading, as well as remembering whatever has been read. Of all the grimoires attributed...