The theory of evolution is the central unifying theory in biology. The introduction of the theory in 1858 was greeted with shock by the mainline Christian churches. These churches have since accommodated to the theory to varying extents, but the fundamentalist traditions remain opposed to evolution. Pope John Paul II recently outlined the position of the Catholic Church on evolution.
First of all, and very briefly, the theory of evolution holds that life arose naturally on Earth about 3.8 billion years ago as an organism similar to a bacterium. From that humble start, all the species of life that now inhabit the Earth have developed.
No species is fixed and immutable but can gradually change over long periods of time. Humans arose from ape-like ancestors.
Next, let me say a word in general about science and religion. It is much more common to hear of conflict between science and religion than to hear of agreement between the two. However, it is only fair to acknowledge that science owes a lot to religion.
In fact, religion made science possible. It was religion, particularly the monotheistic Judaeo-Christian tradition, that initially gave us the concept of a universe created on consistently rational principles. This invited investigation of a logical and systematic nature.
An irrational universe, subject to the capricious whims of a multitude of gods and spirits, could not be studied rationally at all. God was placed beyond time and space, but the concrete world was expected to operate on a rational basis.
Now let me turn to the Pope's recent pronouncement on evolution. This was in an open letter to the Pontifical Academy of Sciences in October 1996.
The Academy is a group of scholars appointed by Rome to inform the Pope about scientific developments. It was holding a plenary assembly at the time and was considering recent research on evolution.
The Pope's letter was published in L'Osservatore Romano, weekly edition, on October 30th, 1996.
Pope John Paul first of all refers back to the Encyclical, Humani generis (1950), issued by Pius XII. This document stated that there was no opposition between evolution and the doctrine of the faith of man and his vocation, on condition that one did not lose sight of some "indisputable" points.
Humani generis considered the theory of evolution to be a serious hypothesis worthy of investigation equal to that of the opposing hypothesis. It cautioned, however, that one should not deal with evolution as though it were a proven doctrine, and it spelled out the condition on which the theory would be compatible with the Christian faith.
Pope John Paul expands on this condition later in his letter.
The letter goes on to deal with the current attitude of the church towards evolution, and I quote:- "Today, new knowledge has led to the recognition of more than a hypothesis in the theory of evolution. It is indeed remarkable that this theory has been progressively accepted by researchers, following a series of discoveries in various fields of knowledge.
"The convergence, neither sought nor fabricated, of the results of work that was conducted independently is in itself a significant argument in favour of this theory."
Next, the letter claims that in fact there are several theories of evolution if we take different mechanisms proposed for evolution into account, and also the various philosophies on which they are based, i.e., materialist, reductionist and spiritualist interpretations. It seems to me that the Pope is on less secure ground here.
It is true that there are arguments over the details of the mechanism of evolution, but there is effective unanimity in biology on the fact of evolution. It is also true that some evolutionists are materialists (who believe that the explanation for everything resides in the material fabric of things), but it is not necessary to be a materialist in order to believe in evolution.
A reductionist philosophy generally prevails in science. The approach is to analyse complex situations by reducing them to simpler component parts, studying these parts and reassembling the whole by putting the parts back together.
This basic scientific approach can provide only natural explanations for natural phenomena, but it does not dogmatically deny the possibility of the supernatural.
By spiritualist philosophy, I presume the Pope means an understanding of evolution in which supernatural forces play a part. And this is where the letter goes next.
The letter states, and I quote:- "The Magisterium is directly concerned with the question of evolution, for it involves the conception of man. Revelation teaches us that he was created in the image and likeness of God.
"The human individual cannot be subordinated as a pure means or a pure instrument, either to the species or to society: he has value per se. It is by virtue of his spiritual soul that the whole person possesses such a dignity even in his body.
"If the human body takes its origin from pre-existent living matter, the spiritual soul is immediately created by God. Consequently, theories of evolution which consider the mind as emerging from the forces of living matter, or as a mere epiphenomenon of this matter, are incompatible with the truth about man. Nor are they able to ground the dignity of the person."
The letter goes on to say that the methods of science are competent only to track the physical progress of life and to place it on a time-line. Science cannot investigate the transition to the spiritual.
The Pope says that analysis of metaphysical knowledge, self-awareness, conscience and religious experience fall within the competence of philosophical and theological analysis.
Pope John Paul's letter is moving and eloquent in its protection of human dignity. The message could be crudely summarised to say - science can have the development of life to the stage of the human body, but God must have the soul.
As a Christian I believe in the existence of the non-material soul but as a scientist I cannot conceive how the soul could naturally arise out of the physical body. Therefore, I can see no way around postulating a divine intervention to account for the soul in humans, although I am constitutionally ill at ease with the idea of God taking a hand in the evolutionary process.
The Pope sees the soul as separable from the body, but not from the mind. We have three entities here - brain, mind and soul. I never had a difficulty in seeing the mind as the brain in action, i.e., the mind is what the brain does.
Therefore, I have no great difficulty in visualising the mind arising naturally from a complex brain. Pope John Paul II does not see it in this manner.
If the mind is intimately connected with the soul, can the mind and consciousness have arisen naturally? I am neither a philosopher nor a theologian, but it seems to me that it is an unnecessary complication intimately to interconnect the mind and the soul.
The Pope may be planting a landmine that will explode in the future. What if science can eventually construct a brain capable of thought from basic raw biological material? Will the next Galileo be a neurobiologist?
William Reville is a senior lecturer in Biochemistry at UCC