I think we are all aware of the imperfections of words, words being themselves concepts.
I think using the term 'nothingness' in a strict sense is problematic. I don't think we can conceptualize 'nothing'. Anything that we can conceptualize must be a 'something' in order to conceptualize it. The very act of conceptualization is creating something in the mind, no matter how abstract it may be. 'Nothing' would have no color, neither white nor black, would have no shape or form, and would have no dimension nor would it relate to any experience or any construct which the mind could create. It would be akin to non-consciousness.
All these words we use to descrube 'nothingness' should be understood as a conceptual convienience and not as a true description of the non-conceptual nature of the subject itself. I don't agree that we can conceptualize 'nothing'.
In Buddhism there is the Void, from which all existence appears. This Void cannot be described and is usually alluded to as "not something, not nothing, not not-something, not not-nothiing", etc. This Void cannot be percieved by the conscious mind.
There is a saying, "woe to him who mistakes the pointing finger for the Moon". The lamp sitting here on my computer desk we conceptualize as 'lamp', but in fact it is not a lamp in reality. It is a form. We can only understand this reality, the thing itself, when we put an end to concept within our mind. Then it resumes its true reality for us. When we try to portray concepts, we are in a sense fooling ourselves. There is nothing 'true' about concepts. And when we try to conceptualize that which is beyond our mind's capability to conceptualize we are imposing our imagination upon that which is beyond imagination, and therefore we only percieve our imagination.
This discussion is interesting in its way, and if after all this if we come to the conclusion that 'nothing' cannot be conceptualized we may have learned something (from my point of view). Sadonis said, "The best thing a person can do is just smack you in the face". Probably that's what the Buddha would have done finally if we had brought this subject to him. We can manipulate words and concepts to our own purpose, quote various gurus and such (as I have done here), but a good slap in the face may be the best answer to this subject.
All this is a fine philosophical entanglement and exercise for the mind, but in the end it seems to me philosophy (like belief) poses questions which philosophy (and belief) itself cannot answer within its own construct. I think this is also true of the mind's capability of creating concepts.
