During the renaissances in thinking led by Shakespeare and Goethe, the first new development in memory techniques for 1,700 years appeared: the Major System. This was the first system that enabled the user to transfer easily and instantaneously from numbers to letters, thus creating the opportunity for a system that could stretch from zero to an infinite number, and which allowed the user to translate any word into its own special number, and any number into its own special letter. This multiplied the opportunity for developing memory techniques 100-fold.

The Mind Map Book, Buzan and Buzan (1991)