I was not talking about scientific "nothing" or void. I was talking about philosophical "nothingness". What nothingness means, in metaphysical philosophy, is that there is no matter and form found. It's a complete emptiness.
However, there were/are some philosophers who don't believe in nothingness. To them, to think of nothingness implies nothingness' existence which, then, is contradictory to the idea of being nothing - for nothing is nothing and it cannot be thought of.