I have heard that people mention long discourses (Diga Nikaya) are not authentic Buddha's discourses (not Buddha's words). The fact that makes me surprised much more is that they say "in Diga Nikaya, Brahmajala Sutta was not discoursed by Buddha".
After I have studied Brahmajala Sutta; such bold words and complete coverage on Indian Brahman and Brahmin religious concepts as well as all modern religious concepts, I thought those kind of very complete specifications of 62 concepts/beliefs could only be named and discoursed origins of them by only Sammasambuddha or someone like Sammasambuddha (who has very complete Panna without any rival can claim or find loophole/falsehood or incompleteness in his discourses).
- What could be the motive of such weak claims?
- Is it more appropriate to find any incorrectness or loophole of Brahmajala Sutta and other controversially claimable Suttas in Diga Nikaya first before saying authenticity of these Suttas?
- Could it be more easier to prove by saying specification and origins of 63 beliefs that was not covered by Brahmajala Sutta?
- Is it correct way to say that Suttas from Diga Nikaya (start from Brahmajala Sutta) are ehipassiko?
- At the time of Buddhahood of Gautama Buddha, all India regions are overwhelmed by Brahmanism and Brahmins. Buddha has only 60 monks which are from rich men of Yasa young guy and friends. It is not inappropriate to convert some Brahmins who had a sense that Atta of Brahmanism was in vain. It was obvious that Sāriputta and Moggallāna are disciples of Sañjaya Belaṭṭhaputta and they joined to Sanga society with 250 disciples of same teacher. DN 12 Lohicca Sutta might be counter question to those scholars who questioned authenticity of Diga Nikaya but actually it makes infinite loop about disagreement.
- Another possible reason about Bramhajala Sutta is Suppiya did blaming on Buddha, Dhamma and Sanga but the sutta did not mentioned what were details words of Suppiya and to what extent Suppiya did false-fully accusing we do not have chance to know. If a leader of such Sanga society did not properly repeal wrong accusation, what kind of leader Buddha would be.
- Sariputta claimed that Buddha's Sila was the best possible Sila a person can keep it clean, unbroken. In Brahmajala sutta, it is where we get a chance to understand/learn Buddha's Sila by grades and it is also role model to future Sanga nonetheless future Sanga has tendency not to keep as many as Buddha prefer to.
- Propagation of Anatta views on Brahmanism overwhelmed Indian region is bold move of Gautama Buddha and many adversary effects should had been expected (need citations here). Scholars can logically do reasoning about it. Immediate decision about not to do any discourses to anyone just after enlightenment was nullified by request of Sahampati Bramha, so it is inappropriate or weak claim that Buddha would not do driving less dusty eyes Brahmins to become monks.
- Gautama Buddha did offensive (if improper reasoning on his) remarks to Maghandi's daughter in Maghandi Sutta. But the explanation was Buddha had Karuna on Maghandi couples and only the daughter was completely out of picture. For this ages of valuation of women lives, this kind of remark will be viewed as very offensive to community and legal level but this was some kind of example that Gautama Buddha did speak if there was great benefit to save Brahmins from unfruitful believes of Atta view and/or Veda.
- It seems like scholars cannot appreciate Buddha converting people who believed Brahmanism but they failed to notice that such big Sanga society cannot be done by overcoming adverse Atta view, worshipping Brahma and caste system.