Buddhism, as it is practiced today, has three principal branches viz. Theravada (the school of the elders), Mahayana (the greater Vehicle) and Vajrayana (the diamond vehicle).Of the three the Mahayana school of Buddhism is spread over a wider geographical area. It covers the vast populace of Tibet, China, Mongolia, Nepal, Vietnam, Korea, and Japan. It is also more diverse in its content as it encompasses a variety of Buddhist schools. It is more emotional, warmer, and more personal in devotion, more ornate in art, literature and ritual. It also has a record of striving to invent or include doctrines agreeable to the masses of the region. It is even seen as being closer to Hinduism as far as the rituals and practices are concerned.
It is in this context that, recently, someone on the Forum asked me a question concerning the proximity of Mahayana Buddhism to Hinduism. The question specifically asked was:
"Is it not true that Mahayana is essentially the way that Buddhism tried to come to terms with Hinduism the main religion of the day? I see Mahayana as the way Buddhism tried to survive in India."
Let me, at the outset, say that I do not agree with the tenor of the question. I also do not agree with its drift or content. Let me explain why I think so.
A. Birth of the Mahayana
1. The concept of Mahayana came about because of the churning of ideas within the Buddhist community at the beginning of the Christian era. A large section of the community strongly felt there was a need for a more emotional, warmer, personal religion adequately disposed to evolution and development. The general tradition connects this evolution to the initiatives of King Kanishka(c 120 A. D) and scholars of the time such as Ashvaghosha (c 120 A. D) and Nagarjuna (c 150 A D).
3. Though the concept of Mahayana was launched officially at the fourth religious council held at Kashmir in first century A.D., the germ- idea was in circulation even a hundred years earlier to that, more as a matter of speculation and argument than as a precise statement.
The evolution of the Mahayana concept came about as a gradual unfolding rather than as a sudden development.
4. At the time when the Mahayana doctrine came up for debate in the fourth religious council, nearly 500 after the historical Buddha attained nirvana, Buddhism had well taken roots in India. It was popular among the masses. It also enjoyed the patronage of kings and Emperors.
It was, therefore, at that time, not in desperate need of a ruse for survival. Further, the Mahayana did not take birth as a reaction to Hinduism.
B. Mahayana is not a Departure from Teachings of Buddha
5. The Mahayana is not a departure from the doctrines enunciated by the historical Buddha. Both the schools – Theravada and Mahayana- accept the fundamental teaching of Buddha implicitly without any questions. Both the schools argue that the basic tenets of their school emanate directly from the teachings of the Buddha. Followers of Mahayana school of Buddhism insist they have not deviated from the teachings of the Buddha instead, they claim to have rediscovered the Buddha’s lost teachings. Many scholars say that Nagarjuna grasped the Buddha’s “seed- idea” of void Sunyata and developed it into a system of thought in his book Madhyamika Karika.
C. Theravada - Mahayana
5. An obvious difference between the two schools is the Bodhisattva ideal. Both schools accept the three Yanas or Bodhis but consider the Bodhisattva ideal as the highest. The Mahayana accepts many mystical Bodhisattvas while the Theravada considers Bodhisattva as a man amongst men and as one who devotes his life for the attainment of perfection, and who ultimately becomes a fully Enlightened Buddha for the welfare and happiness of the world. The Mahayana School transfers the emphasis from personal salvation to universal salvation, from the ideal of Arhat to that of the Bodhisattva. It said, a monk should not be a lamp unto himself, while there is darkness every where
5. During the initial times, it appears the difference between the two schools was not that apparent. As the Chinese traveler I-Ching (635-713 A.D.) put it, “Those who worship Bodhisattvas and read Mahayana Sutras are called Mahayanists, while those who do not do this are called Hinayanists”. It was that simple.
6.However the differences became explicit over a period when (a) each schools adopted its chosen texts –Pali texts by Theravada and Sanskrit texts by Mahayana; and;(b)when the two schools moved away to distinct geographical areas like Sri Lanka ,Burma , Far East on one hand and Tibet , China, Korea and Japan on the other.
D. Reforms within Mahayana
7. The challenges that Mahayana Buddhism faced in distant lands and diverse cultures called upon it to innovate. Buddhism that took root in those countries was not the same as the one practiced in India at the time. For instance, in order to be acceptable to the populace of Tibet it was necessary Buddhism evolve itself into a new form by letting in Bon practices and ideas while firmly retaining its basic Buddhist tenets. In the process, Buddhism took in materials and attitudes native to the soil, lent them a new sense of direction and grafted them with the Mahayana doctrines. It allowed many Bon attitudes, ideas, tribal gods, goddesses, and the associated rituals and instilled in them the spirit of piety (Karuna). Thus, while the form was traditional to the soil, the soul was Buddhist. Bon at the same time also adopted numerous Buddhist practices, attitudes and ideas
A similar process took place in China and Japan where Buddhism imbibed the rituals, practices, attitudes and even deities of the native religions (Tao and Shinto) while retaining the essential Buddhist doctrines at heart. Those religions in turn also modified them selves. It was/is a dynamic process.
8. Thus, Mahayana Buddhism became an umbrella concept for a great variety of sects, from the Tantric Sects found in Tibet and Nepal (secret Yoga teachings), to the Pure Land Sects found in China, Korea and Japan (reliance on simple faith). The Mahayana school of India also gave birth to an inward-looking Chan Buddhism (China), which then crossed the straights to Japan and flowered as Japanese Zen. For Chan and Zen followers, the path to enlightenment is meditation.
In fact, some scholars go further and say the Mahayana is not a single vehicle but rather a train comprising many carriages of different classes.
9. Despite this proliferation in beliefs, Mahayana Buddhism tapers down to two general branches -- the Madhyamika and the Yogacara. While Madhyamika represents the middle view, the middle road, a path of relativity over extremes (e.g., extremes like existence vs. nonexistence, self vs. non-self); The Yogacara School emphasizes yoga -- the practice of meditation. In either case, the path to enlightenment is long and arduous, requiring followers to build up merit in this life to be reborn in the next life with better karma.
E. Mahayana - Hinduism
10. Now, before coming to issue of Hindu influence we can digress a bit. While discussing the similarities among various Indian languages Prof. Emeneau, a well-known American scholar, in his classic paper, “India as a Linguistic Area”, came up with the concept of linguistic area for explaining the underlying Indian-ness of apparently divergent cultural and linguistic patterns. The resemblances between two or more languages (whether typological or in vocabulary), he said, can be due to genetic relation (descent from a common ancestor language), or due to borrowing at some time in the past between languages. He also said, essentially different but geographically and physically proximate languages often exhibit shared linguistic features.
We can perhaps extend this view to cover various religions that took birth or that took root in India. Amanda Coomaraswamy , the great scholar, once said “The more superficially one studies Buddhism, the more it seems to differ from Brahmanism in which it originated; the more profound our study, the more difficult it becomes to distinguish Buddhism from Brahmanism, or to say in what respects, if any, Buddhism is really unorthodox.”. The Buddha did not fight the religion of India of his time .He had a benevolent view towards it and its scholars. He however objected to the ritualistic aspect of that religion. Buddhist Rahula Walpole wrote,” the Buddha was trying to shed the true meaning of the Vedas. Buddha is a knower of the Veda (vedajña) or of the Vedanta (vedântajña) [(Sa.myutta, i. 168) and (Sutta Nipâta, 463].” Hindus scholars have also accepted the Buddha and Buddhism as a fulfillment of Sanatana Dharma.
11. Hinduism and Buddhism influenced each other in many ways. The Buddhist notion of non-injury and compassion toward all living beings took deep roots in the Indian ethos, while Mahayana Buddhism took cue from the traditional Indian methods of devotional worship. Buddhism influenced the growth and development of Indian art and architecture and contributed richly to the practice of breathing and meditation in attaining mindfulness and higher states of consciousness. The Hindu tantra influenced the origin and evolution of Vajrayana Buddhism that flowered in Tibet. The systems of Buddhism and Hinduism are not either contradictory to one another or completely self contained.
12. We may say that in the first few centuries following the nirvana of the Buddha, Buddhism was an integral and significant part of that complex religious character of the Indian subcontinent, which the outsiders called as Hinduism. However over a period thereafter Buddhism crossed the boundaries of the Indian subcontinent and went on to play a much greater role in the whole of Asia. In the process, it developed a very complex sectarian, theological and geographical diversity and a tradition of its own to become one of the most significant and influential religions of the world. Many people who are not familiar with the history of the Indian subcontinent fail to understand the deep connection that existed between Hinduism and Buddhism in the earlier days and the significant ways in which they enriched each other.
F. Conclusion
13. Thus, the birth of Mahayana was not as a reaction to Hinduism .It was a concept that emerged out of churning of ideas within the Buddhist community. Perhaps it was the need of the time. The Mahayana did not deviate from the doctrines enunciated by the historical Buddha .The various forms that Mahayana assumed in different geographical and cultural contexts were a part of the dynamics of its growth. The Mahayana in any country has to be viewed against the broad canvas of that region’s cultural and religious uniqueness. This is true in the Indian context too. Further, the systems of Buddhism and Hinduism are not either contradictory to one another or completely self contained.
14. What happened to Buddhism in India after eighth century and Muslim invasion is another story.
References:
Hinduism and Buddhism - A historical sketch; by Sir Charles Eliot
Timeline, history-Three Main Buddhist schools in Asia | 
