It must have an inner cohesion and inter- dependence.

It must start from a fixed principle.

This has been, and still is, the besetting weakness of the theology of mediation.
It is apt to form itself merely by stripping off what seem to be excrescences from the outside, and not by radically reconstructing itself, on a firmly established basis, from within.

The difficulty in such a process is to draw the line.

There is a delusive appearance of roundness and completeness in the creeds of those who either accept everything or deny everything: though, even here, there is, I think we may say, always, some little loophole left of belief or of denial, which will inevitably expand until it splits and destroys the whole structure.