§ 11. Before closing our discussion of Causality, we must briefly take note of certain special difficulties by which the problem has been complicated in the systems of some eminent philosophers. A distinction has often been drawn between Transeunt and Immanent Causality. In so far as the changes of state of one thing are regarded as occasions of change of state in others, the relation has been technically called one of Transeunt Causality; the determination of a thing’s change of state by its own previous changes has, on the other hand, been named Immanent Causality. As a consequence of this distinction, grave difficulties have arisen in connection with the notion of Transeunt Causality. Such Causality, _i.e._ the determination of the changes of one thing by the changes of others, is of course an essential feature in the pre-scientific view of the world of experience as a multiplicity of interacting things. For systematic Pluralism this conception inevitably presents insoluble difficulties. For it is impossible to reconcile the ultimate absolute independence of the various real things with the admission that the sequence of states in any one depends upon sequences of states in any of the others. If a plurality of things are ultimately independent of each other, it is manifest that each must form a complete whole, self-determined and containing the ground of its details entirely within itself. Conversely, if a thing cannot be explained by a principle of purely internal systematic connection, but requires for its complete explanation reference to an outside reality with which it stands in interconnection, its independence can be only partial. Hence Pluralism, in its more consistent forms, has always sought to deny the reality of Transeunt Causality, and to reduce all causal relations to the internal determination of the states of a thing by its own previous states. Historically, the principal devices which have been adopted for this purpose are (_a_) Occasionalism, and (_b_) the theory of a Pre-established Harmony.