Tāntrism originated from primitive magic. People, outside Chinese cultural circle, call Tantra (Tib. rgyud) as Esoteric Buddhism or Buddhist Esoterism. Recently the most popular usages are Tantric/Tāntrika Buddhism, Buddhist/Buddhistic Tantrism, and Buddhist Tantras or Vajrayāna etc. The westerners had known the term of tantras in 1799 A.D. There are two traditions: one is the Hindu tradition, and the other is the Buddhist tradition. Both of them had been written in Sanskrit, while between them there are different usages and traditions. Etymological interpretations of the word Tantra, as found in the ancient texts, clearly and conclusively point out that originally Tantra had no special religion or metaphysical significance. In the Vedic text the word Tantra occurs in the sense of a loom. It seems easy to understand the warp means the threads over and under which other threads (the weft or woof) are passed when cloth is woven on a loom. The straight one is the warp, which is the Tantra. The weft means cross-threads taken over and under the warp in weaving. So the weft (or woof) equals the term Sūtra. The paper is divided into six parts. The first part is preface, just I have mentioned above, which made a few notes on the word Tantra. Secondly, that the late Indian esoterism means Tantrist Buddhism should be defined. In the third part, I discuss some background of the Tantras orgininating in India. In the fourth part, I explain away the so-called sexual yoga in Vajrayāna. Anyway it belongs to the techniques of psycho-physiological operations, rather than relates to sexual intimacy. In the fifth part, I describe how the Tibetans preserved their India masters' teachings most faithfully. Finally, in the sixth part it is concluded that Tibetan culture is the world's cultural heritage.
