The first impression or attitude that forms the initial core of the mind is existence.
This is the primary, basic attitude.
It's opposite is non-existence.
This is the basic pair of opposites in the mind. It is the primary duality.
You could call it matter and unmatter, or you could call it existence and unexistence.
The moment there is any resistance or forcing in a relationship between one individual and another individual - and remember, humanness has nothing to do with it; it's the individuals involved then there is existence.
And with existence then the relationship is, instead of there just being relationship.
Once you get into isness, that's it, you've had it.
You've got a mind.
The Structure of the Mind