see another?

Where there is a duality, as it were, there one sees another; 

there one smells another; there one tastes another; there one speaks to another ...

But where everything has become just one's own self,

 Then whereby and whom would one see? 

Then whereby and whom would one smell? 

Then whereby and to whom would one speak? 

Then whereby and whom would one hear? 

Then whereby and of whom would one think? 

Then whereby and whom would one touch?

 Then whereby and whom would one understand?

~  Brihadaranyaka Upanishad