so [p.183] pure as it was at its source. Alien waters have entered into the current--waters of very different taste from those which even the Founder expected. These have doubtless polluted the stream. But, on the other hand, good elements--primary and secondary--have entered into the deepest nature of Christianity itself. These have to be taken into account. They have been necessitated by the new and ever more complex situations and conditions into which Christianity has had to enter from generation to generation. It was comparatively easy for Christianity in its early beginnings to include within its compass the whole of life. But by to-day life has branched off in so many new directions; perplexing problems of knowledge and life have made their appearance. We dare not dismiss these to a region outside the sphere of influence of Christianity. Christianity, if it is to remain and increase as a living force, has to interpret these problems; it has to help us to distinguish between the chaff and the wheat. What, then, is the true meaning of Christianity? Eucken shows that it is not possible to determine the nature of Christianity without realising that the nucleus common to all religions lies in the fact "that they manifest and represent a Divine Life, and that such a Life in its inmost foundation is superior to its external configuration and activity, and is able to withstand all the changes of time, and to [p.184] maintain within itself, in spite of all its curtailment through the human situation, _an eternal truth_." This nucleus lies deeper in Christianity than in any other religion. But even Christianity itself is not a pure spiritual nucleus. Much, as we have already noticed, has gathered around it--much that reveals a lower grade of spirituality. All this constitutes the clothing of Christianity. The clothing has been changed again and again in the past. What reason is there for affirming that it cannot be changed again? It is therefore necessary to differentiate between the _Substance_ of Christianity and its _Existential-form_. The Substance constitutes the fundamental Life superior to the world, and has been present throughout the whole of the Christian era; and it is this Substance which has raised men beyond the merely human situation; it is the Substance that has enabled men to overcome the world, and afterwards to see the world from the standpoint of the Divine. In this work of differentiation we are dependent in a very large measure upon the results of knowledge. Such results do not grant us the Substance of Christianity, because this is something which has to be lived into in order to be possessed. The transformation which occurs on account of a change in the Existential-form may indeed prove helpful to the spiritual nucleus itself, because it represents a truth of the intellect-a truth which does not conflict with any [p.185] knowledge outside its own sphere. There are many dangers to be discovered in this process of