This section is from the book "Mahanirvana Tantra (Tantra of the Great Liberation)", by Translated by Arthur Avalon (Sir John Woodroffe). Also available from Amazon: Mahanirvana Tantra: Tantra of the Great Liberation.
Siddhi is produced by sadhana. The former term, which literally means "success," includes accomplishment, achievement, success, and fruition of all kinds. A person may thus gain siddhi in speech, siddhi in mantra, etc. A person is siddha also who has perfected his spiritual development. The various powers attainable, namely, anima, mahima, laghima, garima, prapti, prakamya, ishitva, vashitva, the powers of becoming small, great, light, heavy, attaining what one wills, and the like, are known as the eight siddhi. The thirty-ninth chapter of the Brahmavaivarta Purana mentions eighteen kinds, but there are many others, including such minor accomplishments as nakhadarpana siddhi or "nail-gazing." The great siddhi is spiritual perfection. Even the mighty powers of the "eight siddhi" are known as the "lesser siddhi," since the greatest of all siddhi is full liberation (mahanirvana) from the bonds of phenomenal life and union with the Paramatma, which is the supreme object (paramartha) to be attained through human birth.
A. A.
 
Continue to: