I must begin by saying how much I appreciate the honour of being asked to address a group of scientists on this subject; and my only hope is that what I have to say will not prove entirely irrelevant to the concerns of those who practise experimental science in one form or another, though I suspect that the kind of relevance which I shall suggest is rather a peculiar one.

While the experimental sciences—what is usually meant by ‘science’—have become highly diversified today, so much so that divisions of the sciences such as ‘physics’, ‘chemistry’, ‘botany’ and so on, are so general as to be pretty well unusable, one feature in particular distinguishes theology from all of them and indeed from any other intellectual pursuit whatsoever: the fact that theology itself belongs to the supernatural order. By ‘theology’ I shall always mean ‘sacred theology’ and not ‘natural theology’, which is properly a special way of practising metaphysics. To say that theology in this sense belongs to the supernatural order is not merely to say that its object, what it studies, is something supernatural, the Revealed. It is also to say that it is itself, in its intrinsic movement and apprehension of truth, something supernatural. It is not merely the application of procedures already practised in other fields to a special field, a special set of data, though it certainly is that too, as we shall see: but its very intellectual activity shares the specific character of the special field which it investigates.