According to the Dharma nature chuan cheng bloodline of Holy Tantra Esoteric Buddhism, and the teachings of the ancestors chuan cheng, we understand that when Patron Buddha the Great Sage Sakyamuni Buddha dwelled in this world, the teachings, practice, and chuan cheng of Buddhist esoteric Dharma (or Esoteric Buddhism) already existed.

          In ancient India, when the Patron Buddha the Great Sage Sakyamuni Buddha dwelled in this world, there were numerous non-Buddhist¹ doctrines and various schools competing with each other for supremacy.  From the practice doctrines of these various schools, one can see that esoteric teachings and esoteric methods already existed and were established.

          According to the teachings of the Old Dharma Lord, some of the esoteric teachings and esoteric methods of ancient India had already existed for over seven thousand years, with long historical heritage.  Furthermore, among the learning of various non-Buddhists, esoteric teachings, esoteric methods, esoteric principles, and esoteric practices occupied the advanced theoretical and thinking levels of these various schools of ancient India.

          Ancient Indian schools such as Brahmanism, Vedism, Hinduism, Sankhya, Jainism, Nirgrantha, etc. all had esoteric teachings and esoteric methods as their contents, branches and sects.  The doctrine, theory, and practice of esoteric teachings were either concealed within those various schools, or the esotericism openly acknowledged such as the Gu-ao (archaic and abstruse) School or the Ao-yi (abstruse meaning) School.

          Apparently, these "secret sect" types of school all had their own unique ways or methods for their exchange with "the highest truth of the universe."  They all had their own "complete" metaphysical theories characteristic to each school.

          The Great Sage Ancestral Buddha was renowned for "defeating non-Buddhists".  He established the two major series of the holy teachings' esoteric doctrines of "madhyamika (middle way)" and "vijnanavada (consciousness only)" upon the principles of the teachings.  They were unique and used to guide scholars of various non-Buddhists esoteric schools to convert to Buddhism.

          Patron Buddha the Great Sage Sakyamuni Buddha had all along been well-known for His subduing all schools of non-Buddhists.  It can be visualized that when various esoteric non-Buddhists came to the temple where He resided, and implored the Great Sage to teach and enlighten them, would they be refused by the kind and compassionate Great Sage?

          The answer is: definitely not.

          Generally speaking, it is very difficult for esoteric practitioners who had already faced cosmic realities in their "fruition stage" practice, to return to the "cause stage" of exoteric practitioners who remain at the level of "using expedient means to reveal the reality".  In other words, "esoteric non-Buddhists" need to be effectively treated and subdued by the holy Dharma of esoteric teachings.

          The ancestral Buddha taught and transformed "esoteric methods" non-Buddhists, "secret" non-Buddhists, and "esoteric teaching" non-Buddhists, with the holiest, truest, highest, most supreme, ultimate and perfect "esoteric teachings" and "esoteric Dharma" unique to Buddhism to educate these types of non-Buddhists "path" seekers who already had certain "levels of attainment."  Buddha guided these sentient beings with different root capacities, who had already entered the false route and missed the ultimate truth, to step away from the dark erroneous zones of attaching to "self" and "dharma," and enabled them to realize the brilliant great path of anuttara-samyaksambodhi - the supreme perfect enlightenment.  Thus, the various non-Buddhists were able to truly receive the metaphysical highest cosmic reality under the standardization of the "madhyamika" and "vijnanavada" correct views.

          A lot of evidence show that the Great Sage Buddha used the various Dharma of "Vajra Dhyana," "Vajra Vehicle (Vajrayana)," and "Mantras Vehicle," in His mobilization of "Holy Tantra Esoteric Dharma of Buddhism," as the holy religion's invincible "weapons" in subduing the "various esoteric" non-Buddhists.  Such weapons were perfect, comprehensive, complete, determinate, and all conquering.

          The "various methods and schools of esoteric Dharma" refer to the stages of the nine vehicles of Esoteric Buddhism.  "Esoteric Dharma of Buddhism" is conceptualized because in ancient India where and when the Buddha dwelled in this world, the Great Sage Buddha taught esoteric Dharma without openly establishing an esoteric school.  Furthermore, around where Hinayana sages were gathering, the Buddha even taught against mantra recition.  Apparently, this was a temporary expedient convenience.  As the Buddha was facing a society mingled with beings of various root capacities of Hinayana, Mahayana, and Tantrayana; all of whom He intended to save and deliver.  Thus, there were the needs and convenience of eighty four thousand holy Dharma for treatment.

          The establishment of Holy Tantra Esoteric Buddhism's classification of "nine vehicle stages" of Esoteric Buddhism, is to suit the holy conditions of individuals of various root capacities to practise Tantra.  These individuals are either sentient beings possessing Tantric conditions, or are great path minded beings.  Thus they can be led into the rank of Holy Tantra Esoteric practitioners.

          Therefore, the claims of scholars who believe that: "Esoteric teachings of Buddhism originated after the seventh century."  or even allege that: "It is a product of some member schools of Indian Mahayana Buddhism on merging with Brahmanism." do not tally with the actual situation.

          In fact, Esoteric Buddhism was already taught and practised when the Great Sage Buddha dwelled in the world.  If unconvinced, one can read in detail the four Agamas, which can verify that the Great Sage Buddha taught Sravakayana disciples concrete Dharma of esoteric teachings such as conducting mantras, treating illnesses, safeguarding against snakes, and poison antidotes etc.

          The Great Sage Ancestral Buddha did oppose the use of mantras by Brahmanism, but He was merely objecting to the skin-deep esoteric methods of Brahmanism, which could not attain the ultimate truth.

          Obviously, we appreciate and respect scholars' research results very much.  At the very least, those scholars with contrary views have provided constructive ideas, and have provided thoughts worthy of reference.

          In terms of data relating to this aspect, Holy Tantra Esoteric Buddhism has many holy scriptures (omitted) which can provide evidence.  Let us discuss, exchange views, study, and investigate together in the future.