He's talking about dualities, the nature of paradoxes.
You cannot experience the idea of self without also the idea of selflessness.
The group defines individual existence. I am not myself if there is no one else to differentiate between.
If I am the only of my kind, the idea of self is meaningless, because I'm all there is.
If there are others like me, then I need identity.
But identity is also a function of consciousness. Without consciousness, identity and individuality need not exist.
So then the question becomes what is consciousness? What is a thought?
I'm not really trying to provide any answers, just try and explain the same general idea in a different way.