The article was all over the place. Let's start with the title. "India's vital atheist philosophy" suggests this is a continuous coherent tradition. In fact the article describes several different persons and tendencies occurring at wildly different times and milieus which do not necessarily have any connection together. For instance, one of Prof. Bhattacharyas key findings was that Charvaka and Lokayatika do _not_ mean the same thing. This was a confusion made my later commentators who did not have first-hand acquaintance with those philosophers. How "vital" can a philosophy be if the only reason you know it exists is from the polemics of its opponenents?

In fact by the time Madhavacharya wrote the Sarvadarshanasamgraha in the 14th century Charvaka was as dead as a doornail. (Contrary to the author, nowhere does the SDS say it is describing "the main philosophical schools of the time.") Madhava took sannyasa under the name Swami Vidyaranya and became the head of the Shringeri pitha - the premier seat of Smarta orthodoxy. It is from the SDS (if any Indian source) that Jyoti Phule and Amartya Sen's grandfather learned about Charvaka/Lokayata not from any vital tradition. And if such diverse figures as a Brahmana monk, a Marathi reformer, and a middle-class Bengali know it can you really say it is an "untold story?"

So for whom is this story "untold?" Apparently the "orientalist" scholars. (Never mind E.B. Cowell translated the SDS into English in 1882 and it has been quoted in standard histories of Indian philosophy ever since.) And the Stanford Ecyclopedia doesn't include Charvaka as atheism. That's because there is no evidence to conclude this. As the authors own examples clearly show, the main bone of contention of the Charvakas was on the existence of the next world. One can disbelieve in other worlds without being an atheist (i.e. any animist.) Astika and nastika do not mean "orthodox" and "atheist" merely those who say asti ("it is so") and naasti ("it is not so") to the question of the existence of another world. Hinduism contra Buddhism and Jainism goes on to add "Are the Vedas authoritative?" to the questions that define astika and nastika but that's a different issue. As Prof. Bhattacharya notes, the Charvakas (but not the Lokayatas) do refer to the authority of the Vedas. Jayarasi Bhatta the author of the Tattvoplavasimha (which is a play not a philosophical treatise incidently.) is a Brahmana who describes himself as well-versed in Vedas and other branches of Brahmanical knowledge.

And the from the fact (well-known) that Astika Samkhya and Mimamsa darshanas do not believe in a creator of the universe does not imply that they were atheists. For instance Kumarila Bhatta who complained that Mimamsa is being overrun with Lokayatikas goes on to refute the idea that the universe was created and did not eternally exist. But he also believes that the Vedic Devas are real and present in the sacrificial rite.

Now if you combine all these disbeliefs together you do get something resembling
a modern atheist but why would you do that? Surprise surprise! Hindus are not middle-eastern monotheists. Is that really your stunning insight?

Then there is some unfounded speculation: Could the Indus valley civilization have been secular? Was Vaisheshika originally atheist? etc. Some blunders: Yajnavalkya does not appear in Kathopanishad. Yoga is non-theistic. In fact the primary difference between Samkhya and Yoga is that the latter accepts Ishvara (God -- but not necessarily a creator) as a tattva ("basic principle") and so on.

Then there is a section on how modern-day Dalits are supposedly influenced by this ancient Indian atheistic tradition with the scantiest of evidence and much wishful thinking.

This whole article is nothing but a massive exercise in myth-making. Curious behavior for an atheist don't you think?