The above (paraphrased) was the opinion of two distinguished personalities in the modern era: the late president of India, S. Radhakrishnan, and a very famous Hindu leader, Swami Vivekananda. It is not surprising that the opinions of these two gentlemen, who did not belong to any authentic Buddhist tradition, were not based on Buddhist texts and interpretive traditions. However, it is indeed a matter of surprise that their opinions do not accord with the ancient masters of Vedānta itself, such as Ādi Śankara, who considered the Buddha as someone unreliable for teaching contradictory teachings (the Commentary on the Brahmasūtra 2.2.32)
Even now there is no consensus among scholars regarding the number of Upaniṣads that existed at the time of the Buddha. It is quite possible that few of the earliest Upaniṣads were already in existence before him; however, there is no mention of the name ‘Upaniṣada’ in any of the Buddha’s discourses; nor of Sāṁkhya, which is considered to be one of the oldest schools of thoughts among the six interpretive Vedic schools (Ṣaḍ-darśanas). The Buddha rejects and refutes the philosophical contents of such texts and schools in his discourses without mentioning the name of the Vedic text or school. Interestingly, a few stock phrases are often repeated regarding prominent Brāhmin teachers who came to interact with the Buddha – i.e., they were learned in the ‘three Vedas with their vocabularies, liturgy, phonology, and etymologies, and the histories … skilled in philology and grammar, well-versed in cosmology and the marks of a great man.’ With this reference, we know for sure that three Vedas – probably Ṛg, Sāma and Atharva – existed at the time of the Buddha and around the region where the Buddha lived. Further, from these interactions we understand three important points:
i) The Buddha, while conversing with these learned Brāhmins who came to interact, study or debate with him, accurately cites Vedic practices and philosophies, often to their astonishment. Additionally, he refutes their philosophical positions and practices and convinces them to accept his own system by showing the inherent problems in their system, following which they take refuge in the Buddha. There were thousands of such Brāhmins who had become his disciples. These people wouldn’t be jumping from their own system to the Buddhist fold if the Buddha were teaching something they were already familiar with.
ii) Several Buddhist sūtras/suttas mention the hostility and contempt of Vedic Brāhmins towards the Buddha or his disciples. They use derogatory terms to describe the Buddha – such as ‘shaven head’, ‘menial’, ‘lowly’, ‘outcast’, and so forth. Additionally, some Brāhmins that converted to the Buddhist fold express their sadness to the Buddha, for they were looked down upon by other Vedic Brāhmins for accepting the Buddha’s teachings. This wouldn’t have happened if the Buddha were teaching the same things attested in the Vedas or Upaniṣadic texts.
iii) The Buddha’s philosophical viewpoint is the opposite of that found in Upaniṣadic texts. In dozens of Sūtras/Suttas – such as the Brahmajāla Sutta, the Tilakkhaṇa Sutta, the Anattalakhaṇa Sutta, etc. – the Buddha rejects the idea of a permanent and unchanging entity such as the ātman/brahman that the Upaniṣadic texts hold as the ultimate reality of existence. Furthermore, in the Pañcatraya Sūtra (Pañcattayasutta Sutta; the Sutta of Five and Three), the Buddha alludes to the philosophy of Sāmkhya and what would later be Nyāya-Vaiśeṣika. He divides such permanent and unchanging entities into two types – conscious (saṁjñi ātmā) and unconscious (asaṁjñi ātmā) –and rejects them both. It is to be noted that the ‘puruṣa’ of Sāṁkhya is conscious while the ‘ātmā’ in Nyāya is unconscious. Apart from the five aggregates (i.e. rūpa, vedanā, saṁjñā, saṁskāra and vijñāna), which are impermanent and devoid of ‘self’ (ātmā or atta), the Buddha doesn’t accept any other entities. Additionally, the Buddhist theory of causation, Dependent Origination (pratītyasamutpāda), makes the existence of such a permanent and unchanging entity an impossibility.
Therefore, it is a misconception and misinterpretation to say that the Buddha taught nothing but Vedānta in his lifetime.
