"Biological Evolution: Facts and Theories"

A critical appraisal 150 years after "The Origin of Species"

Pontifical Gregorian University
Rome, 3-7 March 2009

We think that the conditions to reach a true and proper critical dialogue on these complex and controversial questions are rather simple but imperative. The fundamental condition is to make a clear distinction in the field of study, since the ideological confusion makes it impossible to enstablish a dialogue and generates only uninspired pseudo-scientific arguments.

In the first place, we should appraise the role of sciences in perfect autonomy from any other consideration. Accordingly, one should carefully study all the available data coming from paleontology, biosystematics, molecular biology, which provide ever growing evidence for evolution of species.

In a second phase we should focus on the study of the various scientific theories that aim at explaining such an event. Historically, the first theory was Lamarck’s transformism; although several elements of his theory have been surpassed, we cannot dismiss the fundamental role of this great predecessor. In 1859 the theory of natural selection by Charles Darwin was expressed for the first time in The Origin of Species. Darwin’s theory is the cornerstone of the current synthetic theory of evolution, or “neo-darwinism,” with the additions of Mendel’s Laws in genetics and the mutations theory by Hugo de Vries.  This wide and firm scientific research program should be carefully studied, also integrating the several recent developments in various fields of research. This inquiry should follow a rational course with the aim of identifying with the greatest accuracy the phenomena explained by this theory and the ones the theory still fails to account for, making a serene confrontation with other attempts, if any, to clarify the mechanisms of evolution. Keeping the same purely scientific perspective, the study of the origin of man will be undertaken, using the facts that are known as a starting point.

At this level, it is essential to consider the neo-darwinian theory as it is, a scientific theory that evolves continually, trying to integrate an increasing number of elements. Like any other scientific theory, it must be put under scrutiny and must be discussed. For this reason, it must not be considered either as a definite truth, which would transform it into ideology – the very opposite of science – or, on the opposite end of the spectrum, as contradictory to a religious truth, for example. Moreover, one could also discuss the question of possible methodological presuppositions, such as mechanicism or radical reductionism, which might have contaminated such a theory in a philosophical rather than in a scientific manner.

For this reason, the second aspect to be carefully considered, clearly distinct from the realm of positive sciences, is philosophical reflection; this will be addressed both at an epistemological level – to understand which is the epistemological statute of neo-darwinism, for example – and at the philosophy of nature level, utilizing a critical approach, so as to properly consider the numerous philosophical implications stemming from the evolution of species in general, and from the synthetic theory in particular.

Only an appropriate philosophical reflection can articulate, without confusing, sciences on the one hand, and faith and theology on the other hand. Therefore, philosophical reflection on the fact of evolution must logically take place before the theological consideration concerning that fact and the various theories which attempt to explain it. Within the field of Christian theology, the basic point of departure is a suitable exegesis of the Biblical texts that address Creation, starting from the first two chapters of the Book of Genesis. The distinction of literary genres remains one of the greatest lessons to be drawn from Galileo.

In this manner, we avoid any direct argument between creation and evolution, as well as the controversies raised for example by “Intelligent Design,” as if it were an alternative scientific theory to neo-darwinism. A Christian can believe in the providential design of God in Creation, without transforming it into a “scientific theory” that competes with another one: these are definitely different levels of interpretation. However, this in turn requires that no scientific theory is placed as the ultimate explanation of reality, which would reduce it to a pseudo-metaphysics, or to a pseudo-religion – in any case, the opposite of science.