Introduction

The last of the three main branch of Buddhism, Vajrayana, developed around 500 BCE out of Mahayana teachings from northwest India. Vajrayana means  in Sanskrit "Diamond, Unsplittable Vehicle." to highlight its supreme efficacy in bringing enlightenment. In English it is also known as Tantric  Buddhism or Esoteric Buddhism, due to its reliance on sacred texts called  Tantras. From India it spread to Tibet (6th century),China (7th century) and Japan (9th century).

Today the teachings of the Vajrayana school are practiced mostly in Tibet, although  some  schools in Japan still retain many facets of Vajrayana Buddhism.

Main doctrinal traditions: Vajrayana Buddhism

The main claim that characterizes Vajrayana Buddhism is the following: enlightenment arises from the realization that seemingly opposite principles are in reality one. The Truth, personified by a primordial Supramundane Buddha (whose name changes depending on the various tradition), reveals himself in every phenomena, including the bodily existence, so that the mundane world is no more seen as the source of just cravings and sufferings, but also as the medium to liberation. While Mahayana and Theravada teach to reject and deny fears, passions and bodily sensations, Vajrayana teaches  to accept  them as as the purest manifestation of the Absolute in the Relative, and to use them in order to attain liberation. One example of this attitude is the image of Fudo Myoo (see below). This explains  why Vajrayana Buddhism lays great emphasis on colorful rituals that imply an active use of the body, voice and senses, and employs a complex pantheon of deities that symbolize the various aspects in which the Truth reveal itself in this world.

Sacred texts and other main texts: Tantras

Tantras are texts composed around the 5h and 10th cen. CE. They are rather obscure texts, dealing mainly with ritual prescriptions and practices of meditation. The contents of these texts is considered esoteric, that is, only through the mediation of a master a practitioner can understand the symbolism implied within.

Sources' analysis and comment

Source 1

The symbolism of union and sexual polarity is a central teaching in Vajrayana Buddhism, as it expresses the functional unity of Absolute and Relative. In the traditional interpretations the female figure symbolizes Wisdom, the knowledge of the real nature of things that brings to enlightenment, while the male figure symbolizes the Compassion, the will of saving all beings still trapped in the cycle of rebirth. This union of passive Wisdom and active Compassion means that the real knowledge that bring to liberation (Wisdom) must be searched inside the mundane world (Compassion). Moreover, this sexual symbolism expresses also the positive valorization of the bodily experience in the quest of liberation.

Note: Differently from what nowadays pop culture claims, the sexual symbolism is usually understood as a metaphor to teach that even in the most strong forms of desire (like the sexual desire) there is potential for liberation from desire itself. The use of real sexual practices in Buddhism did exist, but was strongly regulated and extremely rare

Source 2

Fudo Myoo is standing on rock (Fudo means in Japanese "immovable", as a rock) with a furious, frightening face; carries a sword in right hand (representing Wisdom cutting through ignorance) and holds a rope in left hand (to catch and bind up demons of desires). It  is conceived as particular emanation of the primordial Supramundane Buddha called in Japanese Dainichi. Fudo express the conversion of anger into liberation, and the flames behind him symbolizes the fire of wrath, energy that can be used to burn away all material desires. That's why he differs so much from traditional, irenic, subjects of Buddhist art.

intercultural and interdisciplinary information

1) Tantrism is the name given by scholars to a style of meditation and ritual which arose in India no later than the 5th century CE. It is a inter-sectary religious phenomena so pervasive that virtually any religious traditions in India, Buddhism included, have its Tantric version.

While Hindu Tantrism remained confined in India, Buddhist Tantrism, thanks to the strong proselytism of Buddhism, spread in East Asia a reached also Japan.

2) The famous Dalai Lama is often confused as the leader of all the Buddhist traditions in the world. But he is not. He is the leader of a specific school of Tibetan Vajrayana Buddhism. See Hinduism sec. 7   Buddhism II. Diffusion in the world sections sec. 5 and 6