Esoteric ("Secret") Buddhism is also known as Yogic Esoteric, Vajrayāna, and Mantrayana (or dharini, "True Word") Buddhism. With origins in India, its doctrine is generally referred to as Tantrayāna (Tantric Buddhism). Its teachings are based on the philosophical theories of the Mādhyamika and Yogic Schools of Mahāyāna Buddhism, the contents consisting mainly of incantations (mantras), rituals, and secularized beliefs. It is believed that the three mystic elements (voice, body, and thought) make a whole embodied in the form of the Buddha. Of the three classics of Esoteric Buddhism on display here, Usnisavijayā Tantra belongs to the "Yogic Section" of Tantrayāna and is part of middle Esoteric Buddhism. Sri Hevajra Tantra belongs to the "Anuttara Yogic Section" of Tantrayāna and is part of later Esoteric Buddhism. Vajra-Wisdom Tantra of Deep Meditation is a combination of Tibetan and Chinese Buddhism that also incorporates elements of Confucianism and Taoism, expounding on the notion of "three-in-one" teachings in ancient texts.