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.

That the earth is a sphere was already known to the Greeks by the time of Plato; and most of them were agreed that the sky too is spherical, as suggested by the daily wheeling motion systematically shared by all but seven of the stars. So far so good, but with the seven exceptions, Sun, Moon, Mercury, Venus, Mars, Jupiter and Saturn, the attempt to understand the structure of the universe ran into difficulties. These seven circled the earth every day just like the ‘fixed’ stars, but in addition they moved against the background of the fixed stars without, it seemed, rhyme or reason. However, as the lunar month and the seasonal years showed, the apparently random movements of the ‘wanderers’ or ‘planets’ concealed regularities that were not always evident at first sight, and this raised the question of ‘saving the appearances’ of the planets, of explaining their movements by displaying the geometrical patterns underlying them.

This was the problem that dominated astronomy in the two thousand years that separated Plato from Kepler: a highly technical challenge, of such complexity that in the thirteenth century, Alphonso X of Castile, exasperated by the difficulties of preparing the Alphonsine planetary tables, said he wished God had consulted him when creating the world. Yet, despite its technicality, the problem of the wandering stars is one of the most significant issues in the whole history of science; for when in the sixteenth century Copernicus proposed a solution according to which the earth was itself merely one of several planets which circle round the sun, his specialist monograph sparked off one of the most profound revolutions ever to occur in human thought.

One sometimes hears it said that ‘the Church’ has changed its mind about evolution; Catholics are now allowed to believe in it, whereas formerly they were not. This is a thoroughly confused remark. Evolution is a biological theory, and biological evidence tells us whether it is true or false. It would he very odd to speak of a theory concerned with neither faith nor morals being officially accepted or rejected as part of the Catholic faith. But because the theory has implications which touch on the faith, Catholics looked for guidance from authority about the attitude they should take towards it where those matters were in question: guidance now given them in the encyclical Humani Generis, which encouraged theologians to investigate those points where the theory bore on truths of faith. The present article is not concerned with the biological evidence, which I accept, nor with an extended theological investigation, but merely with difficulties which Catholics still seem to have about the theory, and which are really philosophical in kind.

The first difficulty lies in the conflict which people still find between the theory of evolution and divine providence. How can we say that God directs the whole course of history if rigid scientific laws determine the way in which living things developed from inorganic matter, and finally evolved man? The problem is really that of understanding how causes in the natural world are related to the causality of God. People tend to think that if natural causes are not independent of God, their dependence must imply his constant interference with them to bring about what he wills.

The works of Teilhard de Chardin, now being published posthumously, appear to be having a considerable a impact on certain sections of the Catholic community on the Continent. The time is hardly ripe yet for the publication of a full critical appraisal of his writings, and the author of this book would not pretend that it is more than an introduction to Teilhard himself, with an exposition of certain features of his writings which appear particularly to call for critical comment. More important at this stage than commentaries, is that the works themselves should be read and talked about. Slowly, then, by constant usage, we shall extract more and more meaning out of those brilliant new words and phrases that Teilhard has introduced into the study of the history of the world: words such as enroulement, to describe the essential feature of the evolutionary process (compare the traditional déroulement); and hominisation, to indicate the unquestioned tendency in evolution, especially in the Vertebrates, for increasing elaboration of the central nervous system without which, so far as we can see, those characteristics which we recognize as essentially human would not be possible. Hominisation becomes, then, the end of the evolutionary process, for it is admitted by not a few biologists today that, of all the species now extant, it is Homo sapiens alone which is capable of making any further major evolutionary advance. This is attributed by Teilhard precisely to Man’s spiritual capacities by virtue of which, in continuation of the process of enroulement, he is offered the possibility (one species representing all the rest) of discovering at the heart of all creation the Omega, present there from the beginning as the Alpha.