To analyze the relationship between philosophy and theology, an interesting debate that took place in 1931 at the Sorbonne, among the members of the French Philosophical Society, is of great interest.
It all began with a visit by Étienne Gilson to his friend Xavier Léon, president of the French Society of Philosophy and director of the Revue de métaphysique et de morale. There he met Leon Brunschvicg, also a professor at the Sorbonne and a famous editor of Pascal. In connection with an article Brunschvicg had written in the journal, they discussed the philosophical importance of St. Augustine and St. Thomas. A lively conversation ensued. In addition, an article by Émile Bréhier, on precisely the same subject, had recently been received in the journal: There is a Christian philosophy (Y a-t-il une philosophie chrétienne?).
Emile Bréhier was a well-known historian of philosophy. He was writing a monumental history and argued that medieval Christian authors did theology but not philosophy: "During these first five centuries of our era there is no Christian philosophy properly so called which supposes a table of intellectual values clearly original and distinct from that of the pagan thinkers [...]. Christianity in its beginnings is not speculative; it is an effort of mutual aid, at once spiritual and material [...]. We hope, therefore, to show, in this and the following chapters that the development of philosophical thought was not strongly influenced by the advent of Christianity and, summing up our thought in one word, that there is no Christian philosophy.". It was the same thesis defended by many enlightened thinkers since the eighteenth century: in philosophy, one must go directly from classical Greek thought to Descartes because, in the middle, in the Middle Ages, there is only theology.
Different ways of understanding "Christian philosophy".
In history, many different things have been called "Christian philosophy". In a very general sense, ancient Christianity was presented as a "philosophy" (St. Justin, for example) because it is a wisdom about the human way of living. In this sense, one can also speak of "Buddhist philosophy" or, in general, of the "philosophy of life" that each person has. In Christian history, the thought of St. Augustine as a whole has also been called "Christian philosophy"; and, in general, the philosophical thought of Christians can also be called "Christian philosophy". But if we use the term "philosophy" in a more academic way, Christianity is not a philosophy, but a religious message, a revelation.
It is convenient to distinguish the fields. Philosophy is based on reason, it justifies itself with rational arguments. Therefore, when we have recourse to faith or to the Christian message to affirm a truth, we are not in the field of philosophy, but in that of theology. It is philosophy only what is done with rational justification. It is a question of principle and method. On this they were all in agreement.
They decided that the topic was interesting for the next session of the French Society of Philosophy. They agreed that Étienne Gilson would present a paper on whether or not there is, properly speaking, a "Christian philosophy". The debate took place on March 21, 1931. An outline was sent to everyone beforehand.
In addition to Étienne Gilson, Jacques Maritain and Émile Bréhier intervened in the debate. And interesting letters were received from the Christian philosopher Maurice Blondel and the historian of philosophy Jacques Chevalier, also the author of the famous History of thought (Histoire de la Pensée). The debate was published by the magazine and is still read with great pleasure. Professor Antonio Livi, a specialist in Gilson's work, has paid a lot of attention to it. Incidentally, the exemplary elegance of the debate and the respect and delicacy with which everyone treats each other is striking. They were friends and shared the same interest in philosophy, even if they held very different opinions.
Intervention by Gilson
Gilson distinguishes three objections and the position of the Augustinians. "It cannot be avoided that the philosophy of a Christian be purely rational, for otherwise it would not be philosophy; but from the moment that this philosopher is also a Christian, the exercise of his reason will be that of the reason of a Christian; which does not imply a reason different from that of non-Christian philosophers, but a reason operating under different conditions. [...] It is true that his reason is that of a subject who possesses something 'non-rational' (religious faith); but where is the 'pure' philosopher [...], the man whose reason is not accompanied by some non-rational element such as faith?".
"What characterizes the Christian is the conviction of the rational fruitfulness of his faith, and that this fruitfulness is inexhaustible. And this, in fact, is the true meaning of the creo ut intelligam of St. Augustine and fides quaerens intellectum of St. Anselm: an effort made by the Christian to deduce rational knowledge from his faith in Revelation. That is why such formulas are the true definition of Christian philosophy."
Medieval authors knew how to distinguish philosophy from theology, and their philosophy was based on rational arguments. It seems to Gilson that the name "Christian philosophy" can be misleading, but it can also be used to show the real influence that Christian revelation has had on the great themes of Western philosophy.
Gilson then developed a large body of research to showcase it in a series of lectures (Gifford Lectures1931-1932), compiled in his great book The spirit of medieval philosophy (1932), which is a classic of Christian thought.
Maritain agreed with Gilson and established a distinction between the nature and the state of philosophy: "It is necessary to distinguish the nature of philosophy, what philosophy is in itself, and the state in which it is found in fact, historically in the human subject, which refers to its conditions of existence and exercise in concrete terms. [...] And so, the appellation 'Christian' applied to a philosophy, does not refer to what constitutes it in its nature or in its essence of philosophy; if it is faithful to this nature, it does not depend on the Christian faith as to the object and also not as to the principles and method". Shortly thereafter, in a lecture in Leuven (1931), he developed the question and published it as a book, De la philosophie chrétienne. Their distinction is reflected in Fides et ratio.
Speeches by Bréhier and Brunschvicg
Émile Bréhier repeated the rationalist thesis that there is properly no philosophy but theology, although he accepted that there are other ways of understanding the question.
Brunschvicg held a similar position, and tended to reduce the importance of the Christian contribution. For him, the novelty of Christianity consists mainly in its mystical impulse. Many of the Christian concepts come either from permanent forms of human religiosity or have been borrowed from Greek philosophy.
The letter of Jacques Chevalier, himself a great historian of philosophy, is relatively brief and substantially agrees with Gilson. To the question of whether Christianity has played an observable role in the constitution of certain philosophies or, in other words, whether there are philosophical systems that are purely rational in their principles and methods, whose existence cannot be explained without reference to the Christian religion, "you have to answer without hesitation yes".. Although "proof of this assertion would require careful and thorough investigation.".
Chevalier illustrates this with the example of creation ex nihilo (starting from nothing). It is "a notion undoubtedly of Judeo-Christian origin that has played a capital role in the constitution of modern philosophy or, if you will, of some of these philosophies". There is nothing similar in Eastern myths or in Greek philosophy. The Platonic demiurge organizes, but does not create; in Aristotle, matter is as co-eternal as form, and they are subject to a "circular generation"; and Plotinus, who is familiar with the Christian notion of creation, rejects it, because, for him, the world cannot proceed directly from the One.
It is a Judeo-Christian idea. And when philosophy has received it, it has been able to develop a new idea of causality: the causality proper to the first cause is an absolute causality. "I think it is not too much to affirm that both this notion of true causality, which is derived from the Judeo-Christian notion of creation, and the correlative notion of personality, are at the basis of all modern science and all modern philosophy. It constitutes, of course, the foundation of the science and philosophy of Descartes, who bases everything, both the real and knowledge [...], on continuous creation, which, in turn, is the expression of the sovereign, independent and immutable will of the Creator"..
Letter from Blondel
Blondel has his own idea about the relationship between philosophy and theology. He believes that Christian revelation has a universal scope, affecting everything and everyone. At its core it is not attainable by reason, but it provides the solution to many problems posed by reason. For this reason, a Christian philosopher, who knows the answers, must be able to make a philosophy that poses the questions rightly and with all their force. Faith serves him as an inspiration, a guide and a purification. It helps him not to be satisfied with philosophy, to recognize its limits and, therefore, to open himself to transcendence, to pose the great human questions well and to prepare himself for the answers that come from God.
What is proper to a Christian philosophy is, precisely, to show the limits, to open the paths and to raise the questions that lead to faith. In this sense, the philosophy that Christians must do becomes an apologetic, a true preparation for the faith. But respecting the two spheres.
In referring to the theme of "Christian philosophy", Gilson was thinking of the contents that faith has aroused in the history of philosophy. Blondel is thinking, rather, of a way of proceeding, of a stimulus to prepare minds to open themselves to Christian truth. This is another way of understanding "Christian philosophy" which is also legitimate.
The debate aroused much interest to better establish how Christian thought had influenced philosophy. Of course, the most important book is that of Gilson, The spirit of medieval philosophy. But many other authors made very interesting contributions. Among others, Regis Jolivet wrote an intelligent essay on the relations between Greek and Christian thought (1931); Sertillanges, an important book on the influence of the idea of creation. And Tresmontant, his beautiful essay on Hebrew thought. In addition, a day of Juvisy studies (organized by the Maritains) was also dedicated to "Christian philosophy" (1933) and counted with the participation of Edith Stein.
A phrase of Heidegger's, spoken in passing in the first chapter of his Introduction to metaphysics: "a Christian philosophy is the equivalent of a 'wooden iron'. [ein hölzernes Eisen]. and a misunderstanding".. And explains: "Certainly, there is an intellectual and interrogative elaboration of the world experienced as Christian, that is, of faith. But this is theology.". To Heidegger it seems a misunderstanding to speak of "Christian philosophy" because it distinguishes the method of each knowledge, but this was defended by all and, as we have seen, in the debate nuances were made that probably did not reach him.
Gabriel Marcel expresses it very well in his lecture on The mystery of being: "It is quite possible that the existence of the fundamental Christian data is necessary. in fact to allow the spirit to conceive some of the notions [...]: but it cannot be said that these notions are under the dependence of Christian revelation. It is not assumed".