I've been wrestling with this problem for some time. My question concerns the concept of 'possibility'. When one says that something is possible, they are saying that something might be but may not be as well. There is an uncertainty. And of course whatever it is cannot both be and not be at the same time. Now, when we say that something is 'not possible', we are saying that something is not and cannot be. There is no uncertainty and the term as used does not seem to be a true negation as is usually meant when the term 'not' is used. What confuses me, is that in when actually trying to negate the concept of possibility, such as when saying 'not possible', aren't we on the one hand saying that 'that which might be' is not, and on the other hand that 'that which may not be' is not as well, and therefore is (or could be)? What may be is not and/or what may not be is. Saying that something is not possible, in this sense, is the same as saying that it is possible, thus making the negation of the concept meaningless. Is this confusion brought about do to a language or linguistic imperfection or peculiarity or just bad logic and fuzzy thinking on my part. Or does the dual nature of the concept of possibility (the uncertainty of either x or y) make negating it meaningless, so that there is always only the possible. I'm confused.