We have seen many researches and references (like "Reviewed Work: Self and Non-Self in Early Buddhism" and many more supporting documents from PTS, Pali text society) that the idea Atta to some extent it exists and can be deduced that Buddha's teachings also consists of "the idea of Atta". The popular references by I.B Horner (need citation here) and some scholars is
atta hi attano natho
In Buddha's teachings and Tipitaka, I do not see a slight extent of existence of Atta or some ambiguities about Atta by Buddha or monks at the Buddha's ages. All Buddha teachings are ubiquitously about Anatta. And Gautama Buddha repealed the very concept ’Atta’ in many Suttas. Since his second discourse “Anatta Latkhana Sutta", Buddha’s teachings are all about Anatta. Anatta is key concept in Buddha's teachings and Gautama Buddha was first and very first person opposite and challenged to popular Atta idealists at the age of his time. My question here is why some scholars and some publications from Pali text society are trying to coerce Atta concept in Buddhism or society of Buddhists? What are the supporting facts that Gautama Buddha and his teachings are self denial to its own Anatta concept? What are the proofs that Buddhism accept/adopt Brahmanism's Atta idea since both are clearly opposed to each other?
Please keep in mind that the words self and not-self are loosely translated, have ambiguous meanings about referring internal and external based on perspective of particular individual being and not applicable/intended words here. Atta and Anatta is what I am referring here.
The definition of Atta
Atta is the word from Brahmanism, it is essence, from Brahma (or whatever creator make it exists), eternal or indefinite period of existence, it has capability of suffering pleasure and pain. It is in each and everyone bodies and pass from life to life. Some outside Buddha’s teachings define Atta as ’soul’ and/or self but precise definition of Atta is highly controversial.