In our capacity as political scientists, historians, or philosophers we all have had occasion at one time or another to engage in debate with ideologists—whether communists or intellectuals of a persuasion closer to home. And we all have discovered on such occasions that no agreement, or even an honest disagreement, could be reached, because the exchange of argument was disturbed by a profound difference of attitude with regard to all fundamental questions of human existence—with regard to the nature of man, to his place in the world, to his place in society and history, to his relation to God. Rational argument could not prevail because the partner to the discussion did not accept as binding for himself the matrix of reality in which all specific questions concerning our existence as human beings are ultimately rooted; he has overlaid the reality of existence with another mode of existence that Robert Musil has called the Second Reality. The argument could not achieve results, it had to falter and peter out, as it became increasingly clear that not argument was pitched against argument, but that behind the appearance of a rational debate there lurked the difference of two modes of existence, of existence in truth and existence in untruth. The universe of rational discourse collapses, we may say, when the common ground of existence in reality has disappeared.
Corollary: The difficulties of debate concern the fundamentals of existence. Debate with ideologists is quite possible in the areas of the natural sciences and of logic. The possibility of debate in these areas, which are peripheral to the sphere of the person, however, must not be taken aspresaging the possibility in the future that areas central to the person (Max Scheler’s distinction of personperiphere and personzentrale areas) will also move into the zone of debate. Among students of the Soviet Union there is a tendency to assume that the universe of discourse, at present restricted to peripheral subject-matters, will, by the irresistible power of reason, expand so as to include the fundamentals of existence. While such a possibility should not be flatly denied, it also should be realized that there isno empirical evidence on which such an expectation could be based. The matter is of some interest, because philosophers of the rank of Jaspers indulge in the assumption that there is a community of mankind in existence on the level of the natural sciences, and that scientists form acommunity. That raises the philosophical question whether community is something that can be established on the level of a common interest in science at all, a question which at present is far from being thought through.
The phenomenon of the breakdown as such is well known. Moreover, the various Second Realities, the so-called ideologies, have been the object of extensive studies. But the nature of the breakdown itself, its implications for the advancement of science, and above all the methods of coping with the fantastic situation, are by far not yet sufficiently explored. The time at our disposition will obviously not allow an exhaustive inquiry concerning so vast a topic; still, I propose in the present paper at least to circumscribe some of the relevant points of such an inquiry. And as a step toward establishing the relevant points, I shall place the phenomenon of the breakdown in historical perspective.
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The Second Realities which cause the breakdown of rational discourse are a comparatively recent phenomenon. They have grown during the modern centuries, roughly since 1500, until they have reached, in our own time, the proportions of a social and political force which in more gloomy moments may look strong enough to extinguish our civilization—unless, of course, you are an ideologist yourself and identify civilization with the victory of Second Reality. In order to distinguish the nature of the new growth, as well as to understand its consequences, we must go a little further back in time, to a period in which the universe of rational discourse was still intact because the first reality of existence was yet unquestioned. Only if we know, for the purpose of comparison, what the conditions of rational discourse are, shall we find our bearings in the contemporary clash with Second Realities. The best point of departure for the comparative analysis of the problem will be St. Thomas’s Summa Contra Gentiles. The work was written as an exposition and defense of the truth of Christianity against the Pagans, in particular against the Mohammedans. It was written in aperiod of intellectual turmoil through the contacts with Islam and Aristotelian philosophy, comparable in many respects to our own, with the important difference however that a rational debate with the opponent was still possible or—we should say more cautiously—seemed still possible toAquinas. I shall reflect, therefore, on the opening chapters of the Summa in which Aquinas sets forth the problem of debate, not simple even in his time.
Aquinas assumes the philosopher, as we have done, in the situation of debate with an opponent; he considers this the philosopher’s situation of necessity. For “as it is incumbent on the sapiens to meditate on the truth of the first principle, and to communicate it to others, so it is incumbent on him to refute the opposing falsehood.” Truth about the constitution of being, of which human existence is a part, is not achieved in an intellectual vacuum, but in the permanent struggle with pre-analytical notions of existence, as well as with erroneous analytical conceptions. The situation of debate thus is understood as an essential dimension of the existence that we recognize as ours; to one part, the quest for truth is the perpetual task of disengaging it from error, of refining its expression in contest with the inexhaustible ingenuity of error. Philosophy, as aconsequence, is not a solitary but a social enterprise. Its results concern everyman; it is undertaken by the sapiens representatively for everyman. More specifically the represented have a right to receive answers not only to their own questions but also to hear answers to brilliant and well propagated errors which threaten to disintegrate the order of society by disintegrating the order of existence ineveryman personally. It is a situation and an obligation that must be faced in our twentieth century as much as Thomas had to face it in his thirteenth. Hence, if the sapiensshuns the situation of debate, especially if he avoids the crucial intellectual issues threatening the beleaguered city, he becomes derelict in his duties to God and man, his attitude isspiritually, morally and politically indefensible.
The philosopher’s office thus is twofold: He must set forth the truth by elaborating it analytically, and he must guard the truth against error. But what is this truth the philosopher has to meditate and to set forth? I have called it the truth of existence, and by using this language I have terminologically modernized the problem that lies at the core of St. Thomas’s endeavour, as well as of the earlier one of Aristotle to which Aquinas refers in the passages under consideration. The modernization is legitimate, as you will see presently, because it does not modify the problem but only its symbolic expression; and at the same time it is necessary, because without it wecannot understand that the scholastic and classic problem is indeed identical with our own. The source of the difficulties we moderns have with understanding Aristotle and Aquinas is the fact that the truth of existence, of the first reality as we called it, in their time was not yet questioned; hence there was no need to distinguish it from an untrue existence; and consequently no concepts were developed for a problem that had not yet become topical. The truth of existence wastaken so much for, granted that, without further preparation, the analysis could proceed to develop the problems of metaphysics as they presented themselves to men who lived in the truth of existence. But let us now have a look at the manner in which Aquinas and Aristotle expressed their problem of truth.
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While the supporting argument is voluminous, the crucial formulations are succinct. Aquinas, following Aristotle, considers it the task of the philosopher to consider the highest causes of all being.
The end of each thing is that which isintended by its first author or mover. But the first author and mover of the universe is an intellect. The ultimate end of the universe must, therefore, be the good of an intellect. This good is truth. Truth must consequently be the ultimate end of the whole universe, and the consideration of the wise man aimsprincipally at truth.
Aquinas then refers to the authority of Aristotle himself who established
that first philosophy is the science of truth, but of that truth which is the origin of all truth, namely, which belongs to the first principle whereby all things are. The truth belonging to such a principle is, clearly, the source of all truth; for things have the same disposition in truth as in being.
So far the text (SCG I, 1. Met. alpha ellaton, 1,993b20–30).
At first hearing, I presume, these formulations will sound as strange to you as they did to me. There is talk about a first mover of the universe—who must be assumed to be an intellect—from whom emanates somehow an order of being that is at the same time an order of truth. Why should we be concerned with a prime mover and his properties?—you will ask. And does the matter really improve when Aquinas identifies the prime mover with the God of revelation and uses the Aristotelian argument for the prime mover as a demonstration of the existence of Cod? At the risk of arousing the indignation of convinced Aristotelians and Thomists must say that I consider such questions quite pertinent. The questions must be raised, for we do no longer live, as did Aristotle and even Aquinas, at the center of a cosmos, surrounding us from all sides spherically, itself surrounded by the outer sphere of the fixed stars. We can no longer express the truth of existence in the language of men who believed in such a cosmos, moved with all its content by a prime mover, with a chain of aitia, of causes, extending from existent to existent down to the most lowly ones. The symbolism of the closed cosmos, which informs the fundamental concepts of classic and scholastic metaphysics, has been superseded by the universe of modern physics and astronomy.
Nevertheless, if we admit all this, does it follow that Aristotelian and Thomist metaphysics must be thrown on the scrap heap of symbolisms that once had their moment of truth but now have become useless?
You will have anticipated that the answer will be negative. To be sure, a large part of the symbolism has become obsolete, but there is a solid core of truth in it that can be, and must be, salvaged by means of some surgery. Two stages of such surgery seem to be indicated:
(1) The first operation must extend to the demonstrations which depend for their validity on the imagery of a cosmos that is no longer ours. If however we survey the body of demonstrations in support of the formulations I have presented, and if we remove from it everything that smacks of cosmological symbolism, there remains as a piece de resistance the argument that a universe which contains intelligent beings cannot originate with a prima causa that is less than intelligent. Though the context of the argument is still the cosmos, at least the argument itself draws specifically on an experience of human existence which as such is independent of the experience of the cosmos.
(2) The second operation must extend to the prime mover itself. We must distinguish between the symbolic construction and the reality to which it refers; and we must be aware of the curious relations between the firmness of conviction that such a reality exists and the credibility of the construct. If the motivating experiences are known to the reader and shared by him, the construct will appear satisfactory and credible; if the experiences are not shared, or not even too clearly known, the construct will become incredible and acquire the character of an hypostasis. Aristotle could indulge in his construction with assurance because the experiences which motivate the symbolism were taken for granted by everybody without close scrutiny; and Aquinas, in addition to living in the same uncritical safety of experience, could as a Christian theologian blend the truth of the prime mover into the truth of revelation. Today the validity of the symbol, and with its validity the reality to which it refers, is in doubt, because the experiences which motivated its creation for their adequate expression have slipped from public consciousness; and they could slip from public consciousness with comparative ease, because neither were they set forth with sufficient explicitness, nor did the problem of experience and symbolization come into clear focus at all, in classic and scholastic metaphysics. Hence, in order to reach the truth contained in the apparently hypostatic construct, we must make explicit the motivating experiences.
The immediate experiences presupposed in Aristotelian metaphysics are not difficult to find in the classic sources, if one looks for them; but after all this preparation, I am afraid, they will come as an anticlimax because of their apparent simplicity. For we find ourselves referred back to nothing more formidable than the experiences of finiteness and creatureliness in our existence, of being creatures of a day as the poets call man, of being born and bound to die, of dissatisfaction with a state experienced as imperfect, of apprehension of a perfection that is not of this world but is the privilege of the gods, of possible fulfillment in a state beyond this world, the Platonic epekeina, and so forth. I have just mentioned Plato; if we survey this list of experiences, we shall better understand why for Plato (who had a sharper sensitiveness for the problems of existence than either Aristotle or Thomas) philosophy could be, under one of its aspects, the practice of dying; under another aspect, the Eros of the transcendent Agathon; under still another aspect (that leads us back to the formulations of Aristotle and Aquinas) the love of the Wisdom that in its fullness is only God’s. In these Platonic conceptions (the catalogue is not complete) we can see philosophy emerging from the immediate experiences as an attempt to illuminate existence, Moreover, we can understand how philosophy, once it had, thanks to Plato, developed its symbolism and become a going concern, could gain something like an autonomous life of construction and demonstration, apparently independent of the originally motivating experiences, how it could grow into an enterprise that would have to become unconvincing when, due to historical circumstances, the reader did no longer share the philosopher’s understanding of existence.
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We have assembled the data of the problem of experience and symbolization as far as they were immediately connected with the formulations of Aquinas and Aristotle. We can now attempt the exegesis of existence that is implied, though not explicitly given, in classic and scholastic metaphysics. In the course of this attempt, however, further data of the problem will emerge that will compel us to revise the initial propositions. The reader should be warned, therefore, that after the first we have to make a second start.
Human existence, it appears, is not opaque to itself, but illuminated by intellect (Aquinas) or nous(Aristotle). This intellect is as much part of human existence as it is the instrument of its interpretation. In the exegesis of existence intellect discovers itself in the structure of existence; ontologically speaking, human existence has noetic structure. The intellect discovers itself, furthermore, as a force transcending its own existence; by virtue of the intellect, existence not only is not opaque, but actually reaches out beyond itself in various directions in search of knowledge. Aristotle opens his Metaphysics with the sentence: “All men by nature desire to know.” I shall not bother you with the detail of Aristotle’s Argument on the point, because I suspect that in his etiology of being, i.e., in the doctrine of the four causes and the organization of the demonstrations according to the four causes, we touch again one of the areas of symbols that is incompatible with the present state of science and, therefore, will have to be abandoned to a large part, if not entirely, in order to reach the core of truth. I shall rather use a shortcut and divide the objects to which the desire to know reaches out into the two classes of (1) things of the external world and (2) human actions.
With regard to things the desire to know raises the questions of their origin, both with regard to their existence (I include under this title both the hyletic and kinetic arguments) and their essence (the eidetic argument). In both respects, Aristotle’s etiological demonstration arrives ultimately at the eternal, immaterial prima cause as the origin of existent things. If now we shift the accent back from the construct of doubtful validity to the experiences that motivate its construction, and search for a modern terminology of greater adequacy, we find it offering itself in the two great metaphysical questions formulated by Leibniz in his Principes de la Nature et de la Grâce, in the questions: (1) Why is there something, why not nothing? and (2) Why is something as it is, and not different? These two questions are, in my opinion, the core of true experience which motivates metaphysical constructions of the Aristotelian and Thomist type. However, since obviously no answer to these questions will be capable of verification or falsification, the philosopher will be less interested in this or that symbolism pretending to furnish the “true” answer than in the questions themselves. For the questions arise authentically when reason is applied to the experiential confrontation of man with existent things in this world; and it is the questions that the philosopher must keep alive in order to guard the truth of his own existence as well as that of his fellow-men against the construction of a Second Reality which disregards this fundamental structure of existence and pretends that the questions are illegitimate or illusionary.
Corollary I: Heidegger stresses very strongly the first of Leibniz’ questions, but neglects the second one. Nor does he pay any attention to the Aristotelian argument of the final cause (to be treated presently). His fundamental ontology is based on an incomplete analysis of existence. Even at this initial stage our analysis of existence shows already its importance as an instrument for classifying Second Realities and their various techniques of construction, one of them being the omission of parts of the experience of existence.
Corollary II: The symbolism providing an answer to the questions is of secondary importance to the philosopher. That, however, is not to say that it does not have an important function in protecting the order of existence both in man and society. For the development of an answering construct, even if it should have to be revised in the light of a later, more penetrating analysis of existence, will at least guard for a time against error concerning the truth of existence. But only for a time. For the structure of existence is complicated; it is not known once for all. If it be forgotten that the answer of the construct depends for its truth on the understanding of existence that has motivated it; if it be erected into an idol valid for all time; its effect will be the very opposite of protection. For the sensed, if not clearly known, invalidity of the symbol at a later point in history will be extended by the critics of the symbol to the truth nevertheless contained in it. An obsolete symbol may have the effect of destroying the order of existence it was created to protect.
The second class of objects considered by Aristotle, more immediately our concern as political scientists, is human actions. With regard to this class the demonstration of Aristotle is more easily understood. To be sure, the analysis is cast in the form of an etiological demonstration like the others, this time concerning the final cause, but the etiological skeleton of the analysis can be more easily discounted because the generically human experience cast in the dubious form is immediately intelligible. Moreover, on occasion of the final cause the style of Aristotle changes noticeably; all of a sudden it becomes warm and incisive as if now we had reached the heart of the problem; and it becomes discursive enough to make it clear that here indeed wetouch human existence at its center. The demonstration concerning the final cause, we may say, is the model demonstration; the three arguments concerning the aitia of things are derivative in the sense that their persuasiveness ultimately derives from the validity of the demonstration concerning the final cause. Hence, I shall quote the decisive passage:
The final cause is an end which is not for the sake of anything else, but for the sake of which everything else is. So if there is to be a last term of this kind, the process will not he infinite (apeiron); and if there is no such term there will be no final cause. Those who maintain an infinite series do not realize that they are destroying the very nature of the Good, although no one would try to do anything if he were not likely to reach some limit (peras); nor would there be reason (nous) in the world, for the reasonable man always acts for the sake of an end—which is a limit (peras).
We must discount, as I said, the etiological language. If that is done, Aristotle insists that human action is rational, but that rationality hinges on the condition of an ultimate end. The indefinite regress from means to ends, which in their turn are means to further ends, must be cut short at some point by an ultimate end, by a summum bonum. The limit to the chain of means and ends is the condition of rationality in action. This in itself is true; to be sure, there would be pragmatic rationality, if a project of action adequately coordinates means toward an end, but there would be no substantive rationality in any action, if the whole network of a man’s action could not be oriented toward a highest good from which such rationality radiates down to the single actions. Aristotle, however, goes farther on this occasion. Not only would the nature of the Good be destroyed without a limiting good that is no means to a further end, but there would be no reason (nous) in the world at large, because a man who has reason (noun echon) will only act for the sake of a limit-end. The limit seems to be something inherent in reason; and this qualification appears in the context of the analysis of action, betraying that here we have reached the experiential origin from which derives the argument concerning a limit also in the demonstrations concerning the knowledge of things. For the demonstrations culminating in the assumption of a prime mover do not rely ultimately on the proof that a thinker who denies the existence of a prima causa and assumes an infinite chain of causation will involve himself in contradictions (for there is no reason why the universe should not be unintelligible and on closer analysis should not involve the thinker in unsolvable contradictions), but on an experience that reason is indeed embedded in the order of being and it is the property of reason to have a limit. We have returned to the initial proposition concerning human existence (common to Aristotle and Aquinas) that intellect discovers itself as part of human existence, Here, in the exegesis of existence, seems to lie the critical area in which originate the propositions, advanced as self-evident, on the level of metaphysical doctrine. We must examine this problem of reason in existence once more.
Corollary: The modern reader, unless he is an expert in metaphysics, will have difficulties in understanding the Aristotelian etiology, as well as our present analysis, because the term aition, rendered in modern languages as cause, does not have the meaning of cause which the modern reader associates with it. The aitia have nothing to do with cause and effect in the natural sciences; they refer to a relation in the hierarchy of being that we can neutrally term “derivation.” Aristotle can say for instance (Met. 994a311): “The hyletic generation of one thing from another cannot go on ad infinitum (e.g.flesh from earth, earth from air, air from fire, and so forth without end): nor can the kinetic causes form an endless series—man, for example, being moved by air, air by the sun, the sun by strife, and so on without limit.” Obviously Aristotle’s etiology is still deeply embedded in the Ionian speculation on the cosmos, which in his turn is still close to the realm of mythical symbolization. The etiology, therefore, must not be understood as having anything to do with the chain of cause and effect in time, in the modern sense. The problem of the limit belongs strictly to the analysis of existence; it has nothing to do with the infinity or createdness of the world. Aristotle himself held firmly that the world exists from infinity; his rejection of the infinite regress pertains exclusively to the hierarchy of being culminating in the prime mover. Moreover Aquinas follows him in this issue: no philosopher, he concedes, has ever given a valid reason why the world should have a beginning in time; his conviction that the world is not infinite in time but created does not rest on philosophical argument but on faith in revelation, It should be noted that Aristotle was not emotionally upset, as far as we know, by the infinity of time; and we may wonder whether he would have been upset by the infinity of space that became acutely apparent with the development of physics and astronomy since the sixteenth century A.D. The question is of interest, because ever since Pascal it has become a fashion in the interpretation of modernity to acknowledge in the loss of man’s position at the center of a closed cosmos one of the causes of psychic disturbance and unbalance. The interpretation of modernity would result in a quite different picture, if the infinity of time and space were experienced as disturbing because existence has lost its truth, and with its truth its balance.
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In the light of the preceding analysis, which has introduced new factors into the problem of existence, we shall now make our second start, repeating first the propositions that will have to stand:
Man discovers his existence as illuminated from within by Intellect or Nous. Intellect is the instrument of self-interpretation as much as it is part of the structure interpreted. Existence, we said, has noetic structure. It furthermore turned out that Intellect can transcend existence in various directions in search of knowledge. These tentative formulations can now be given more precision. By virtue of the noetic structure of his existence, we may say, man discovers himself as being not a world unto himself, but an existent among others; he experiences a field of existents of which he is a part. Moreover, in discovering himself in his limitation as part in a field of existents, he discovers himself as not being the maker of this field of existents or of any part of it. Existence acquires its poignant meaning through the experience of not being self-generated but having its origin outside itself. Through illumination and transcendence, understood as properties of the Intellect or Nous, human existence thus finds itself in the situation train which the questions concerning origin and end of existence will arise.
Corollary: The preceding description seems to me more exact than Heidegger’s descriptive term Geworfenheit. The passive geworfen requires a subject that does the throwing. Either the state of Geworfenheit must be made explicit by naming the subject, perhaps a daemonic creator in the gnostic sense; or the term must be considered methodologically defective inasmuch as it introduces an element of construction into the strictly noetic description of existence.
But where is the origin and end of existence to be found? As a preliminary to the answer we must interpret the phenomenon of questioning itself; and for this purpose we must add to illumination and transcendence two further properties of the Intellect, the properties of ideation and reasoning. Through illumination and transcendence existence has come into view as an existent thing, in a field of existent things. Through the ideational property of the Intellect it is possible to generalize the discovered characteristics of existence into a nature of existence, to create an idea of existence, and to arrive at the proposition that origin and end of existence are to be found in one existent thing no more than in another. To be not the origin and end of itself is generically the nature of existent things. With this proposition we have reached the experiential basis for extensive demonstrations of both Aristotle and Aquinas that the infinite regress in search of origin can have no valid result; the postulate of the peras, of the limit, is the symbolism by which both thinkers acknowledge the truth that the origin and end of existence is not to be found by ranging indefinitely over the field of existent things. But if it is not to be found in the field of existent things, where is it to be found? To this question, Intellect, by virtue of its reasoning power, will answer that it is to be found in something beyond the field of existent things, in something to which the predicate of “existence” is applied by courtesy of analogy.
Corollary: The analysis of existence has to proceed step by step; and it has to use verbal expressions such as “illuminate,” “become aware,” “transcend,” and so forth. The appearance of a process in time thus created, however, must not be taken for reality. The process is inherent to the analysis, not the existence. In reality all the moments of the structure, distended into analytical steps, are present at once and “known” at once in pre-analytical experience. Pre-philosophical wisdom has its compact expressions—such as “What comes into being must perish”—which at an intuitive glance size up the nature of existence. The analysis of existence can do no more than make explicit what everyman knows without it. That situation raises the question: to what purpose is the analysis undertaken at all—a question that will be dealt with presently in the text. And beyond this question arises the further one: to what purpose should an understanding of existence be expanded into the symbolic forms of metaphysics of the Aristotelian or Thomist type; what purpose could be served by the demonstrations of the prime mover, converted by Aquinas into proofs for the existence of God, especially since they prove nothing that is not known before the proof is undertaken? I have tried to show that the knowledge of the something that “exists” beyond existence is inherent to the noetic structure of existence. And this result is confirmed by Aristotelian and Thomist demonstrations in which the postulate of the peras, whenever it is formulated, is richly studded with the suspicious adverbial expressions of “evidently,” “obviously,” “clearly” which indicate that the premise of the argument is not derived from any demonstration, but that the prime mover which emerges from the demonstration has in fact been smuggled in with the unproven premise. In search of the meaning of such demonstrations (setting aside the previously mentioned usefulness of symbols for protective and defensive functions) there seems to suggest itself the possibility that demonstrations of this type are a Myth of the Logos offered by the Intellect as a gift of veneration to the constitution of being.
At this point the analysis must stop. Any further elaboration would only obfuscate the basic structure just outlined. Hence, I shall not enter in such problems as the via negative, or via remotiva, or analogia entis, which are rational instruments for arriving at clarity about the something; for all reasoning in such forms makes sense only if there is agreement on the structure of existence which requires the pursuit of its problems by such means. As in the case of the questions formulated by Leibniz, the philosopher is more interested today in the experiential structure which motivates speculation than in the answers themselves. The analysis has tried to show that the problems of transcendence, the questions of origin and end, and the postulate of the limit, are inherent to the noetic structure of existence; they are not doctrines or propositions of this or that metaphysical speculation, but precede all metaphysics; and these problems of existence cannot be abolished by discarding this or that speculation as unsatisfactory or obsolete. In an age that has good reasons to doubt the validity of large parts of classic and scholastic metaphysics, it is therefore of the first importance to disengage from the metaphysical efforts of the past the truth of existence that has motivated and informed them.
I have again used the expression “truth of existence.” We can now define it as the awareness of the fundamental structure of existence together with the willingness to accept it as the condicio humana. Correspondingly we shall define untruth of existence as a revolt against the condicio humana and the attempt to overlay its reality by the construction of a Second Reality.
Corollary: The analysis of existence here offered pertains only to the structural elements that have informed the demonstrations of classic and scholastic metaphysics. It does by far not exhaust the structure of existence; large areas, as for instance historical existence, have not even been touched.
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We have traced the problem of truth in reality as it appears in the strange-sounding formulations of Aquinas and Aristotle to its origin in the noetic structure of existence. We shall now resume the problem of debate as it presented itself to Aquinas.
The Summa Contra Gentiles defends the truth of faith against the Pagans. But how can one do that, if the prospective partner to the debate will not accept argument from Scripture? Let us hear Aquinas himself on the question. It is difficult to argue the truth of faith against the Gentiles, he admits, because they do not agree with us in accepting the authority of any Scripture by which they may be convinced of their error. And then he continues:
Thus, against the Jews we are able to argue by means of the Old Testament, while against heretics we are able to argue by means of the New Testament. But the Mohammedans and Pagans accept neither the one nor the other. We must, therefore, have recourse to natural reason, to which all men are forced to give their assent.
The passage formulates succinctly the problem of debate in the thirteenth century and together with it, by implication the profound difference which characterizes the situation of debate in our own time. For every debate concerning the truth of specific propositions presupposes a background of unquestioned topoi held in common by the partners to the debate. In a debate with the Jews the unquestioned topoi are furnished by the Old Testament; in a debate with heretics, by the New Testament. But where do we find them in the debate with the Gentiles? It seems to me no accident when in the answer to this question Aquinas shifts from the earlier language of Intellect to the language of Reason, without further explaining the shift. We remember our analysis of existence: We had to distinguish between the various properties of Intellect, between Illumination, Transcendence, Ideation and Reasoning. If Aquinas believes that he can rely on the power of Reason to force the assent of the Gentiles, he tacitly assumes that the reasoning of the Gentiles will operate within the same noetic structure of existence as his own—a quite justified assumption in view of the fact that the Mohammedan thinkers were the very transmitters of Aristotle to the Westerners. For obviously—that is, obviously to us—the logical operations of Intellect qua Reason will arrive at widely different results, if Reason has cut loose from the condicio humuna. The unquestioned topoi which Thomas has in common with the Gentiles of his time, to whom he addresses his argument, so unquestioned that he does not even formulate them but can take them for granted, are the topoi of existence. He can justly assume that his opponents are just as much interested as he is himself in the Why and How of existence, in the questions of the nature of man, of divine nature, of the orientation of man towards his end, of just order in the actions of man and society, and so forth.
These however are precisely the assumptions that we can no longer make in the situation of debate in our time. Going over again the list of Aquinas, we must say that we cannot argue by the Old Testament, nor by the New Testament, nor by Reason. Not even by Reason, because rational argument presupposes the community of true existence; we are forced one step further down to cope with the opponent (even the word “debate” is difficult to apply) on the level of existential truth. The speculations of classic and scholastic metaphysics are edifices of reason erected on the experiential basis of existence in truth; they are useless in a meeting with edifices of reason erected on a different experiential basis. Nevertheless, we cannot withdraw into these edifices and let the world go by, for in that case we would be remiss in our duty of “debate.” The “debate” has, therefore, to assume the forms of (1) a careful analysis of the noetic structure of existence and (2) an analysis of Second Realities, with regard to both their constructs and the motivating structure of existence in untruth. “Debate” in this form is hardly a matter of reasoning (though it remains one of the Intellect), but rather of the analysis of existence preceding rational constructions; it is medical in character in that it has to diagnose the syndromes of untrue existence and by their noetic structure to initiate, if possible, a healing process.