notion

It’s the very basic notion that women can… think complex thoughts.

What if we could use the notion of quantum entanglement?

This is the notion that even Einstein famously didn't like when he first encountered it, that two separated particles can somehow be instantaneously in communication with each other.

We’ve been rendered exceptionally lonely by the unwittingly cruel notion of a soulmate.

That really seems to be in us the outmost layer of the brain, which is the neocortex, and that's the physical substrate of our conscious experience of the world, including notions of self.