This term is generally translated as meaning penance or austerities. It includes these, such as the four monthly fasts (catur-masya), the sitting between five fires (pancagnitapah), and the like. It has, however, also a wider meaning, and in this wider sense is of three kinds, namely, sarira, or bodily; vacika, by speech; manasa, in mind.
The first includes external worship, reverence and support given to the Guru, Brahmanas and the wise (prajna), bodily cleanliness, continence, simplicity of life and avoidance of hurt to any being (ahimsa). The second form includes truth, good, gentle, and affectionate speech, and the study of the Vedas. The third or mental tapas includes self restraint, purity of disposition, silence, tranquility, and silence. Each of these classes has three subdivisions, for tapas may be satvika, rajasika, or tamasika, according as it is done with faith, and without regard to its fruit; or for its fruit; or is done through pride and to gain honour and respect; or, lastly, which is done ignorantly or with a view to injure and destroy others, such as the sadhana of the Tantrika-sat-karrna,(1) when performed for a malevolent purpose (abhicara).
1. S’anti, Vasikarana, Stambhana, Vidvesana, Uccatana and Marana.
See Indra-jala-vidya; the Kamaratna of Naga-bhata; Sat-karmadipika of S’ri-Krsna Vidya-vagisa Bhattacarya, Siddha-yogesvari-Tantra, Siddha Nagarjuna, Kaksa-puta, Phet-karini, and other Tantras (passim ).