Nondualism is a state of consciousness that doesn't separate any aspect of yourself from everything else around you. As a matter of experience through meditation it's possible to actually see clearly that your own conciousness is the space in which everything you experience happens. This space is free from any dichotomies as everything takes place in a singular condition of consciousness. Note that this is talking about conciousness - what it's like to be you in every moment - and not about objective reality. I believe the objective reality is filled with many other things and minds, just not the same things and minds that I perceive.