What is Tantra?
An excerpt from an interview between Ralph Abrams and Prem Pranama from the Buddhist Information website. The whole interview is good for those looking for an introduction or explanation of Tantra, but the beginning of it, quoted below, captures the whole essence of Tantra in a nutshell. The url of the article follows the quote.
R: The word Tantra is thrown around quite a bit in spiritual circles these days, and it often means very different things. I'd like to start off with the simple question: What is Tantra?
P: Tantra is the hot blood of spiritual practice. It smashes the taboo against unreasonable happiness; a thunderbolt path, swift, joyful, and fierce. There are many different types of paths. Some touch you like a gentle spring rain, but Tantra is the wild summer thunder storm churning with creation, destruction, bliss and emptiness. Tantra is a wild mother tiger - if you approach her with right motivation, right intention, and integrity, she'll suckle you at her breast; but if you come to her in a sloppy way, she'll rip apart your body-mind, eat you for dinner, and shit out what's left.
R: Wow! I think that this sense of joyful abandon and the force and bliss you've described would make the Tantric path attractive to many people. Plus the fact that it is known to be a very swift path to enlightenment.
P. Swift, yes. But the Tantric Vajrayana path is complex and can be dangerous. It requires a strong, well integrated sense of self prepared through careful preliminary practice. Otherwise it is possible for the practitioner to make gross errors in judgment. On the Tantric path, it is perhaps easier to become the ultimate form of egohood and delusion than it is to become free. You can start off intending to liberate the tyranny of ordinary appearance into primordial awareness and end up crystallizing the ego into diamond-hard delusion. There is no authentic Tantra without profound commitment, discipline, intelligence, courage, and a sense of wild, foolhardy, fearless abandon.
-from "An Interview with Tantric Master Prem Pranama" at the url of http://www.buddhistinformation.com/what_is_tantra.htm