Mantra-sadhana is an essential part of spiritual discipline. The most potent way of realizing a 'devata' is with the help of the bija-mantra. And when an aspirant gets devoted to the highest of all mantras, and meditates thereon, he or she reaches eventually the goal of life which is 'moksa'. The phrase 'Garland of Letters' refers to the necklace worn by the Great Goddess which each bead representing one of the 51 letters of the Sanskrit alphabet. This book is an attempt to explain to an English knowing reader an undoubtedly difficult subject. It is natural that, given the difficulty and the mystery which surrounds the subjects that strangers to India have failed to understand Mantra. They jumped to the conclusion that it is meaningless superstition. This is the familiar argument of the lower mind which says what I cannot understand can have no sense at all. Mantra is, it is true, meaningless to those who do not know its meaning. But there are others who do, and to them it is not superstition.