If we perceived nothing but change, we should be incapable of distinguishing between our changes and the change outside us, for all succession in our experiencing would be experience of what was successive, and there could be no distinction between psychology and science. Our experience of reality is not like either of these suppositions, but like both of them combined. Some succession of our experiencing is experience of the co-existing, some experience of succession. Reality stretches out beyond us in space, some of it changing and some of it permanent; we cannot tell simply from the difference in what we perceive whether the difference comes from change in us or change in the thing. We can tell that only on the assumption that we are having fragmentary views of a whole that is continuous. The only continuity we know is the continuity of our own experience made possible by memory, and we try to interpret that experience in the light of the larger continuity of the world which our experience breaks up. As we go from one place to another, notice now this thing, now that, we can test interpretations made on this assumption. Wrong interpretations are those which make our experience inconsistent. If we thought that what happened at one time had no relation with what happened at another, that anything might happen any time, our experience and our own life would be the merest jumble. Our experience attains consistency only as we learn more and more to disentangle the differences in experience which come from our changes, from the changes and the variety which are part of the whole connected system of reality, of which we see now one fragment, then another. The distinction between succession in our apprehending and apprehension of succession, which is the basis of all experience of change, implies the recognition of change as not arbitrary but part of a connected system of reality. As Kant puts it in his formulation of the principle of the analogies of experience, "Experience is only possible by means of the representation of a necessary connection of perceptions."