The present work is a defence of the Tantra, of which Sastra the author is an adherent and a polemic, undertaken in the interests of Hindu orthodoxy in its Sakta and Tantrika form against secularism on the one hand, and on the other the religious eclecticism and various reforming movements, of which, when the book was first written, the Brahmasamaj was a leading type. In fact, in parts the book reads like an orthodox Catholic protest against modernism and is thus interesting as showing how many fundamental principles are common to all orthdox forms of belief, whether of West or of East. The author of the Tantratattva (on which this translation is based)is a well-known Tantrik Pandit, preacher, and secretary of the Sarvamgalasabha of Benares, who knew no English. His work, which is written in Bengali, may therefore be taken to be an accurate popular statement of modern orthodox views on the subject treated by him. The word Tattva is a very comprehensive one, which is by no means always easy to translate. The author has rendered the title of the book as Principles of Tantra, though, may be, it should be Subjects of Tantra. The work deals with chosen topics of Tantra. This, however, also involves a statement of certain fundamental principles which govern Sastrik teaching on the subjects dealt with, and this as well as the contents of possible future volumes must be the justification for giving the book ambitious title.