Any attempt to examine the main trends of contemporary theology may well open with the salutary reflection that history always has its own way of defying our efforts at exact analysis. The events which seem to have the quality of new departures are inexplicably linked with the past out of which they have grown and to which, in some sense and degree, they are related as effect to cause. This is especially true when we find ourselves in the realm of ideas, and Christian theology must not be supposed, even by those who are convinced that it takes its rise from a “revelatum”, to be of such a nature as to provide, or allow, an exception to the general rule. Only when we compare the broad features of periods sufficiently separate in point of time and temper can we recognise differences so sharp as to be unmistakable.