How, then, does Kant obtain something of which space and time can be regarded as really relations? He reaches it by a transition which at first sight seems harmless. In stating the fact of perception he substitutes for the assertion that things appear so and so to us the assertion that things produce appearances in us. In this way, instead of an assertion which relates to the thing and states what it is not but only appears, he obtains an assertion which introduces a second reality distinct from the thing, viz. an appearance or phenomenon, and thereby he gains something other than the thing to which space can be attached as a real predicate. He thus gains something in respect of which, with regard to spatial relations we can be said to have _knowledge_ and not illusion. For the position now is that space, though not a property of things in themselves, _is_ a property of phenomena or appearances; in other words, that while things in themselves are not spatial, phenomena and appearances _are_ spatial. As evidence of this transition, it is enough to point out that, while he states the _problem_ in the form 'Are things in themselves spatial or are they only spatial as appearing to us?'[4] he usually states the _conclusion_ in the form 'Space is the form of phenomena', i. e. phenomena are spatial. A transition is thereby implied from 'things as appearing' to 'appearances'. At the same time, it is clear that Kant is not aware of the transition, but considers the expressions equivalent, or, in other words, fails to distinguish them. For both modes of stating the conclusion are to be found even in the same sentence. "This predicate [space] is applied to things only in so far as they appear to us, i. e. are objects of sensibility [i. e. phenomena]."[5] Again, the common phrase 'things as phenomena' implies the same confusion. Moreover, if Kant had realized that the transition was more than one of phraseology he must have seen that it was necessary to recast his argument. [4] This is Kant's way of putting the question which should be expressed by asking, 'Are things spatial, or do they only look spatial?' [5] B. 43, M. 26. Cf. _Prol._, § 9 fin. with § 10 init. It may be said, then, that Kant is compelled to end with a different distinction from that with which he begins. He begins with the distinction between things as they are in themselves and things as they appear to us, the distinction relating to one and the same reality regarded from two different points of view. He ends with the distinction between two different realities, things-in-themselves,[6] external to, in the sense of independent of, the mind, and phenomena or appearances within it. Yet if his _argument_ is to be valid, the two distinctions should be identical, for it is the first distinction to which the argument appeals.[7] In fact, we find him expressing what is to him the same distinction now in the one way and now in the other as the context requires.