Yet if I ask what you mean by contingent, and you answer, that the notbeing of which is possible, then I would gladly know by what means you intend to cognize the possibility of this not being, if you do not represent a succession in the series of appearances and in this succession an existence, which follows on the not being (or conversely), and thus a change; for that the not being of a thing does not contradict itself is a lame appeal to a logical condition, which is certainly necessary for the concept but far from sufficient for real possibility; for I can suspend any existing substance in thought without contradicting myself, but I cannot at all infer from that to the objective contingency of its existence,.e.