What did the buddha teach ?
The buddha taught there was no atma (eternal soul). He looked for a cosmic self and couldnt find one.
What the buddha meant was there was no body soul. How could there be as the thoughts arose and disappeared with no origin.
The ego arises from a chain of thoughts and nothing more, therefore there was no body soul.
The Buddha was clever and was pointing out that we are all part of the universal mind. This is called soul centric thinking or buddhi.
The Buddha goes even further to say there is no consciousness. He means no individual solid consciousness, again an attempt to define an ego.