Shri Sacchidananda Sarawati in his Introduction to the Brahma Sutra Bhashya Kannada translation, Part 1, page 14, which says,
Translation
- As in Vedanta other Darshanas are taken up for refuting them, when other Darshanas take up Vedanta for refuting it, the others always consider Vedanta to be Advaita.
This a claim Swamiji is making to prove that Vedanta was considered as Advaita itself even before Shri Adi Shankaracharya.
My question is which are those Pre-Shankara books available today, which considers Vedanta to be Advaita? What did they say about Advaita?