Again, it is impossible to concede any meaning even to the central 'law of thought' itself--the Law of Identity ('A is A')--except as a postulate. Outside of Formal Logic and lunatic asylums no one wishes to assert that 'A is A.' All significant assertion takes the form 'A is B.' But A and B are _different_, and, indeed, no two 'A's' are ever _quite_ the same. Hence, when we assert either the 'identity' of 'A' in two contexts, or that of 'A' and 'B,' in 'A is B,' we are clearly _ignoring differences which really exist--i.e._, we postulate that in spite of these differences A and B will for our purposes behave as if they were one ('identical'). And we should realize that this postulate is of our making, and involves a risk. It may be that experience refuses to confirm it, and convicts us instead of a 'mistaken identity.' In short, _every identity we reason from is made by our postulating an irrelevance of differences_. There is thus, perhaps, no fundamental procedure of thought in which we cannot trace some deliberately adopted attitude. We distinguish between 'ourselves' and the 'external' world, perhaps because we have more control over our thoughts and limbs, and less, or none, over sticks and stones and mountains; fundamental as it is, it is a distinction _within_ experience, and is not given ready-made, but elaborated in the course of our dealings with it. Similarly, in accordance with its varying degrees of vividness, continuity, and value, experience itself gets sorted into 'realities,' 'dreams,' and 'hallucinations.' In short, when the processes of discriminating between 'dreams' and 'reality' are considered, all these distinctions will ultimately be found to be judgments of value.