You are here

Science, Religion and Aristotelian Theology


Science and the Future of Mankind, Pontifical Academy of Sciences, 2001

1. The Relationship between Science and Religion

Many scientists and theologians maintain that today, between science and religion, there is a relationship of  “consonance”, and this is not based, like in the past, on the fact that there could be some problems, not yet solved by science, which can have a religious solution. They think that, through the methods of contemporary science, it is possible to admit, in a probable, if not in a necessary way, the existence of God and the creation of the world by him. This is the case, for instance, of Richard Swinburne, who thinks that the existence of God is, from a point of view of the calculus of the probabilities, the most simple and therefore the most probable hypothesis for the explication of the world, such as it is known by science1. In an analogous way, John Polkinghorne thinks that the world's creation by God is compatible with a physical theory of the stationary universe as well as with a scientific conception of its origin. And this means, in the case where it is conceived as the initial “big bang”, as well as in the case where it is conceived as the quantistic fluctuation of an “inflated vacuum”. Moreover, Polkinghorne believes that also the apparently anthropic direction of the evolution can be explained by a scientific theory of an “informational, not energetic, agency” of God2.

Some of the contents of Christian faith, indeed, cannot be explained from a scientific point of view, and they cannot be admitted by science either, because they seem to contradict the laws of nature, even if these are conceived in an indeterministic or a probabilistic way. I am thinking, for instance, to the resurrection of Jesus Christ, or to the virginity of Mary associated to her motherhood of Christ, which seem to contradict the laws of biology, and also to many other miracles. In these cases it is not sufficient to appeal to a simple act of faith, because Christian faith, as the Pope said in his last encyclic Fides et Ratio, cannot be a faith in the absurd, i. e. in the impossible. Even those scientists and theologians that I mentioned before, admit that between science and religion there must be a relation of consonance, i. e. of compatibility. And the existence of any contradiction would violate this relation.
In order to eliminate these contradictions, and to assure the compatibility between science and religion, it is necessary to admit the dependence of the nature on an absolute power, which can make exceptions to the laws of nature, i. e. the same kind of dependence which is involved in the notion of creation, as it is stated by the Bible. Now, the concept of creation, considered in the sense of a total dependence of the universe on a transcendent God, even purified from those mythical characters which are described in the Bible, can surely be accepted by an act of faith, but it presupposes some necessary conditions. And the absence of these conditions makes the faith absurd, unacceptable from any point of view.

2. The Conditions of the Consonance

In my opinion, these are the conditions:
1. the existence of an absolute, i. e. infinite, power, which does not depend on any other being and on which every other being depends;
2. the transcendence, i. e. the difference, the complete heterogeneity, of a being which possesses such a power respect to the nature, i. e. respect to the universe, included humanity, with its history, its culture, its science, its technology;
3. the character of intelligence of this being, which gives him the capacity of thinking, willing and acting.
The first of these conditions, i. e. the existence of an absolute power, is necessary in order to explain the exceptions to the laws of nature, because only the power that created these laws can violate, or suspend them. But this means that there must be something, or someone, which is superior to nature, because it is not submitted to its laws. This means, therefore, that the nature, or the universe, or the infinite multiplicity of the worlds - in other words, the reality which is the object of our scientific investigations -, is not the whole reality, but there must be something other, on which depends the reality that constitutes the object of science. Obviously, I am not claiming in this moment that this something other does necessarily exist (this is a philosophical problem, and it would need a wider discussion), but I'm saying that its existence is necessary in order to admit the consonance between science and religion.

The second condition, i. e. the transcendence of a being who possesses the absolute power, is necessary because, if the power capable of making exception to the laws of nature was immanent, i. e. internal, to nature, it should be a part of it, and therefore the same nature would be on one hand governed by some laws and on the other hand, it would be capable of making exception to them, and this would be a contradiction. It is true that for some scientists many events in nature, even the biological evolution, depend only on the chance. But in this case the chance should be itself a law of nature, and, to this respect, the events mentioned before - the resurrection of Christ, the virginity of Mary - would be an exception and therefore they must be impossible. I don't believe, in fact, that those scientists who consider that natural phenomena are due to chance would admit the possibility, by chance, of miracles. Even if we imagine an immense human power, capable to go beyond the laws of nature that we know so far, this power should be a part of nature and it should be submitted to its general laws. So, even this immense power could not explain the events which apparently are in contrast with the general laws. Otherwise, it should be a magical power, incompatible with science.

The third condition, i. e. the intelligence of a being provided with an absolute power is the most evident, because only an intelligent being, capable of thinking and willing, can act on nature and on history in an intentional way, the way required to explain the events mentioned above. On the other hand, every kind of religion (at least religions inspired by the Bible) admits an intelligent and willing God, but the condition for this admission, which is the faith, is the possibility of conceiving a similar being in a rational way, or at least in a way which is not contrasting with reason. All these conditions - this is my point - are not a question of religion (i. e. of a faith in a divine revelation, because these conditions are also the conditions for the possibility of the revelation itself), nor of science, because they go beyond the field of a scientific investigation. Therefore, they are matter of a discourse which is neither religion nor science, that is a discourse which we cannot indicate by no other name than philosophy, or better a particular type of philosophy, the metaphysics, or still better a particular type of metaphysics, i. e. the metaphysics of transcendence.

3. The Aristotelian Theology

As a matter of fact, all these conditions were satisfied by a philosopher, who didn't know the Bible and who was not influenced by it, in any sense, i. e. Aristotle. He realized these conditions through a process which he claimed to be rational, i. e. philosophical: this process may be criticized from a philosophical point of view or, on the contrary, it may be accepted as a valid philosophical demonstration: this is an open question for a philosophical discussion. But, in any case, it was historically included in a philosophical context and it was absolutely uninfluenced by any religious faith. According to the philosophers believing in religions inspired by the Bible – i. e. the Jews (as Avicebron and Maimonides), the Muslims (as Alfarabi, Avicenna, Averroes) and the Christians (as Albert the Great and Thomas Aquinas) – the Aristotle's formulation of these conditions was as a necessary premise to the religious faith. A necessary premise from a logical point of view, not from a psychological point of view, and obviously it was not a sufficient premise.

The “unmoved mover” (whether it is only one or a multiplicity), whose existence Aristotle tries to demonstrate in the XIIth book of his Metaphysics (i. e. in the so called “Aristotelian theology”), has an infinite power, because – as Aristotle explicitly affirms – it has the capacity of moving the heaven for an infinite time (1073 a 8-9); it is transcendent respect to every other being, because it is the only unmovable being, while all the others beings are moved (1071 b 17-20); and it is intelligent, because it thinks (the act of thinking is its self being, it is its self essence) and it wills (as it is proved by the fact that, according to Aristotle, it is happy). It has also the capacity of acting, because -as I tried to demonstrate in many writings - it is not only a final cause, but also an efficient cause of the movement of the heavens3. Therefore, according to Aristotle, “he” - now we can use the personal pronoun, because we are speaking of a person - is a God, and this is a consequence of the fact that he is eternal and happy (these are the characters that ancient Greeks attributed to gods), even if the is not a creator God (1072 b 26-30).

Obviously, I am not claiming that Aristotle's unmoved mover is the Bible' God: as I said, he is not a creator God. For Aristotle he is just a mover, even if by moving the heavens he is the cause of every generation and corruption on the earth, i. e. of life and death of every living beings. And, he didn't reveal himself to the man: Aristotle does not know any divine revelation. May be - but this is not sure - he doesn't know nor love the man: in some passages Aristotle seems to think that God knows and loves only himself, but in other points he affirms that wise men are beloved by gods. Therefore Aristotle's God has not the sufficient characters to be exactly the God of the Bible. But the characters he has, i. e. transcendence, intelligence, infinite power, are necessary for being the God of the Bible, in the sense that they are the necessary conditions for a creator God. From a philosophical point of view, it's important to add that Aristotle's unmoved mover has an advantage that the Bible's God doesn't have, i. e. he wasn't known by an act of revelation, but he was discovered by a philosopher only with human means, i. e. observation, reflection, and reasoning.

4. The Necessity of a Metaphysics

My aim, in this occasion, is not a defence of the Aristotelian theology, as it was historically realized; nevertheless, I believe that, in order to ensure the compatibility between science and religion, it is necessary to have a metaphysics of the sort of the Aristotelian theology – i. e. a metaphysics admitting the transcendence of the Absolute. This theology, or it's better to say, this metaphysics, is called “Aristotelian”, may be because Aristotle was the only philosopher, not influenced by the Bible, who reached the idea of a transcendent God only by rational ways. This metaphysics does not pretend to demonstrate the contents of the religious faith, but it just allows us to establish the logical conditions for their possibility, i. e. to create a sort of space, whichgoes beyond science, and without this space religion would be impossible. In order to believe in the religious sense, it is not necessary to profess explicitly such a metaphysics, but this kind of metaphysics is necessarily involved, from a logical point of view, in every authentic act of religious faith.

It is a very poor metaphysics, because it does not include the whole “natural theology”, such as it was developed by Christians (but also Jews and Muslim) philosophers in the middle age (but also in the modem age). This kind of metaphysics could be defined a "weak" metaphysics, from an epistemological point of view, i. e. in the same sense in which scientific theories with a poor cognitive content are called "weak theories". The fundamental issue of this metaphysics, in fact, is based on the idea that the world of our experience, which forms the object of our scientific investigation, does not coincide with the entire reality. For this reason, the world of the experience is not an absolute world, it is not self-sufficient, and it doesn't have in itself everything it is necessary to explain it. We would say that this metaphysics only creates a space. But, just in virtue of its weakness, this metaphysics is very strong from a logical point of view, because it is extremely difficult to refute it. In order to refute it, in fact, it would be necessary to demonstrate that the world of our experience can be completely explained by some factors which are immanent to it, i. e. that it is an absolute: a result that any scientific theory can hardly pretend to obtain.

To tell the truth, at the end of the XXth century the main alternative advanced by scientists to the metaphysics of transcendence, i. e. to theism, is not a metaphysics of immanence, of the same kind of positivism, or materialism, like in the XIXth century. At the end of the last century a large part of scientists thinks that the alternative to metaphysics is the appeal to the pure chance; this is the thesis that the whole universe, with its actual structure and order, included the existence of life and man, is the result of an infinite series of changes, exclusively due to the chance. This position seems to me a renounce to an exhaustive explanation, rather than a claim of a perfect explicability of the universe by its internal factors. But in fact, if the chance is considered the only possible explanation of the universe, it becomes an exhaustive explanation, i. e. an explanation which considers the universe as perfectly self-sufficient and which does not admit any further research, an explanation which, at its time, suffices completely to itself.

A similar attitude seems to me the negation not only of the philosophical spirit, but also of the scientific research and in general of any critical sense. The | existence itself of science and philosophy, and their continue and perhaps infinite desire of knowing, is the best refutation of that attitude. This never satisfied desire of knowing, like the awareness of an incomplete and inadequate explanation of the universe, is not only a requirement of human reason, but - in a realistic perspective, which is the prevailing attitude of scientists — it corresponds to a real feature of the universe itself, i. e. to its incapability of explaining completely itself, of having in itself all those factors which are necessary to its complete explanation. In this way the metaphysics of transcendence results to be not only the necessary condition for the compatibility between science and religion, but also the necessary condition for a genuine scientific attitude towards the universe, i. e. a fair admission of the problematic character of our experience of the world.

1 See R. Swinburne, The Existence of God, Oxford University Press, 1979.

2 See J. Polkinghorne, Belief in God in the Age of Science, Yale University Press, 1998.

3 See E. Berti, Da chi è amato il motore immobile? Su Aristotele, Metaph. XII 6-7, "Méthexis. Revista Argentina di Filosofia Antigua", X, 1997, pp. 59-82; De qui est fin lemoteur immobile?, in M. Bastit ed J. Follon (eds.), Essais sur la ihéologie d'Arìstote, Louvain-la-Neuve 1998, pp. 5-28; The unmoved mover as effìcient cause in Aristotle's Metaph. XII, in T. Pentzopoulou-Valalas (ed.), Aristotle on Metaphysics, Thessaloniki, Aristotle University — Department of Philosophy, 1999, pp. 73-81.

M. Berti, The Relationship between Science, Religion and Aristotelian Theology Today, in "Science and the Future of Mankind" (Vatican City: Pontificia Academia Scientiarum, 2001), pp. 228-234.