That is correct, so far as it goes; though, as we shall see in a moment, it does not go quite far enough. Meanwhile, you must clearly realise that _the processes which compose the perceptions and ideas are extremely variable_. We have already discussed this matter; we have seen that the perception of an object and the idea of the same object do not by any means correspond, term for term, like original and copy; the form of our ideas depends, in the first instance, upon our imaginal type, and secondarily upon the special circumstances under which they appear (pp. 139 f.). When, therefore, we speak of ‘the later appearance of an idea in the same situational context,’ we really mean the appearance of that complex of mental processes which, under the law of imaginal type and under the special circumstances of the moment, has taken the place of the original complex. In the next chapter we shall be discussing the ‘memory-image,’ and you will then be shown how radically an idea may be transformed; so radically, that it may be likened rather to a translation than a copy of the perception, rather to a rendering into another language than a reproduction. If you want a catch-phrase, to hold this fact of change in mind, _think of association as a marriage by proxy_; the marriage-bond, the situational context, remains the same, but the parties are represented by very variable mental complexes. [Illustration] Now for the law once more! _The formula does not go far enough; for while it covers the movement of ideas within a single situational context, it does not show how we may pass, as we undoubtedly do, from one situational context to another._ Here a diagram will, perhaps, make things plain. Suppose that we start out with an idea _a_, composed of core and context, and lying within the wider situational context of the right-hand oval. The appearance of _a_ is followed, let us assume, by the reappearance of _b_, which lies within the same situational context. The idea _b_ may be followed, in its turn, by _c_. But since _b_ belongs also to a second situation, represented by the left-hand oval, it may be followed instead by the idea _x_; and in that event we shall have travelled from the one situational context to the other. Whether _c_ or _x_ comes up is a matter which depends entirely upon the relative strength of the associative tendencies at the moment. The diagram, it is needless to say, is immensely over-simplified; we have placed _a_, _c_, and _x_ within _one_ situational context only, and we have made the ideas _follow_ one another in single file; but it shows how our formulation of the law must be extended, if we are to ‘get in’ all the facts. We must add: _If certain of these reappearing ideas belong also to a different situational context, they will tend to be accompanied, again according to circumstances, by the ideas which formerly occurred together (as perceptions or ideas) within that context_.