Western metaphysics takes its starting point in the formulation of that root question which asks after its own object: "¿What is being?"⁽¹⁾. For, in effect, "there is a science which studies being qua being, and the properties inherent in it in virtue of its own nature"⁽²⁾. And yet from the outset, metaphysics is aware of the extraordinary difficulty involved in dealing with its proper object. Because "(...) it is impossible (...) for being to be a genus of existing things"⁽³⁾, since it is characteristic of the genus that the differences should lie outside it and yet there can be no differences that lie outside being. In this way metaphysics dodges ab initio what will continue to act as a temptation: the conception of its central theme as something supremely abstract and empty of content, and hence able to be inserted into a formal-logical framework⁽⁴⁾.

The best and most successful defence against such ever recurring risk comes from the following Aristotelian claim: "The term 'being' is used in various senses"⁽⁵⁾. In this fundamental thesis we find in a radical and precise way a conviction that reality as such -- being in itself -- cannot be fully grasped by our thought, and hence, the quest for the knowledge of its internal structure divides into different paths of approach, to which the different types of linguistic expression correspond.

Metaphysics is transcendental science. As a transcendental branche of knowledge its object surpasses us, in such a way that its unity does not exclude an internal tension towards plurality. But as a form of knowledge that seeks after itself as a science, it has to articulate its expressions with precision in order to stick to the principal differentiations of its own object.

The decisive discovery of the analogical character of being, thus, does not fit into a semantic research so much as into an investigation of the ontological which is truly unique. On this point alone, one must already be aware that the classical Aristotelian treatment of the senses of being is very different to that undertaken by current analytical philosophy regarding a similar question, oriented in this latter case to an almost exclusive look at logic and language. It should come as no surprise then that the different investigations -- the Aristotelian and the analytical -- should appear to be heterogenous.

It also happens that this difference between the two approaches is ever further emphazided by the manner in which Aquinas tackles it. For even if it is obvious that the Thomistic doctrine on the different meanings of being relies on Aristotle as its chief source, it is no less true that St Thomas Aquinas develops this issue from the perspective of Christian revelation, something that could not have been explicit in Aristotle. And it is precisely in this paper that I will look to show -- especially on what refers to the distinction between proper being and being as true -- that the decisive influence of Aristotle was not obstacle to Aquinas shedding new light on the matter.

Aristotle did not carry out only one classification of the differents senses of the word 'being'. But the clearest and most complete and metaphysically relevant one was that which presents us with a list of four rubrics. We are not talking about four senses -- the actual count would be at least fifteen -- but rather about four classifications headings, of four group of senses. In fact, the resulting senses from this classification cannot be added up since each one of the rubrics looks to a different semantic or ontological field, and as a consequence we are dealing with four different criteria of classification.

This aspect of the Aristotelian clasiffication -- which is ever more notorious in Aquinas -- has not been sufficiently emphazided by sistematic metaphysics, leading sometimes to simplistic and impoverished portrayals. Because we are not dealing only with a richer enumeration in the genuine Aristotelian and Thomistic tradition, in comparison to contemporary approaches: its defining feature lies in the classifications being open and differentiated among each other. The frugal framework presented by analytical philosophers in their critique of metaphysics -- with their typically triadic distinction between predication, identity and existence⁽⁶⁾ -- responds to the use of only one of the criteria of classification, of a formal-semantic nature; an exclusivism that accounts for the kernel of its metaphysical criticism. The many-hued aspect of classical treatment shows that the "interest"of realistic metaphysics does not lie in submitting oneself to the demands of a perflectly formalized method, but rather in sticking to reality just as it is and as we talk about it. The ontological perspective takes primacy over the semantic in Aristotelianism, but this does not lead to obscurity or confusion, because the corresponding ambits are explicitly differentiated, establishing a foundational order between them.

The two most complete texts about the senses of being in Aristotle's Metaphysics would appear to the Book V (Chapter 7) and the Book VI (Chapter 2).

In Book V we read the following: "'Being' means, first, accidental being, second, absolute being (…) The senses of essential being are those which are indicated by the figures of predication; for being has as many senses as there are ways of predication (…) Again 'to be' and 'is' mean that a thing is true, and 'not to be' that it is false. Similarly in affirmation and negation (…) Again 'to be' means that some of these statements can be made in virtue of a potentiality and others in virtue of an actuality"⁽⁷⁾.

In Book VI he reiterates these distinctions in another way: "But since the simple term 'being' is used in various senses, of which we saw that one was accidental, and another true (not-being being used in the sense of 'false'); and since besides these are the categories, e. g. the 'what', quality, quantity, place, time and any other similar meanings; and further besides all these the potential and actual (...)"⁽⁸⁾.

Franz Brentano considered this last clasiffication as "the most complete", for which the former serves as an explanation and clarification with examples⁽⁹⁾. In his Commentary to the Metaphysics of Aristotle, Aquinas points out that the order in the enumeration of the first text correspons to a gradation of perfection in each use of the meanings of being⁽¹⁰⁾. We should realize, however, that the ordering of four groups of the senses of being that appears in the second text throws the succesion of the diverse perspectives adopted in each one of the rubrics more cleary into relief:

1. The coincidental being or ens per accidens is distinguished from being by itself or ens per se from a logical-semantic perspective of "formal" character.

2. The being as true or ens ut verum, in its difference with proper being or ens proprium, can be ascribed to a semantic dimension of "material" nature.

3. The division of being that comes out of a consideration of the figures of predicación or categories moves on to the ontological level of "categorial" nature.

4. Being as actuality and being as potentiality correspond, in this last case, to an ontological consideration at the "transcendental" level.

We are dealing hence with a progressive approach from the mind unto reality itself: from the ens secundum rationem (on kata logon) to the ens secundum naturam (on kata physin). It is necessary to insist, though, that the application of these four criteria of classification do not fence off certain meanings of being that should be completely independent the one from the other. According to the order put forward, one goes from the least basic to the most fundamental, given that the logical-semantic level is grounded in the ontological plane, and the categories are grounded in the transcendental principles. And just as the grounding is present in the grounded, so then the latter senses are present in the earlier ones: in (1) reside the senses (2), (3) and (4); in (2) the senses (3) and (4); in (3) only (4), and none in this last one.

This presence of some senses of being in others has not been systematically dealt with by the Greek commentators, nor by the medieval ones, and has been almost completely ignored in Neoscholasticism and in contemporary scholarship. And yet it is of great theoretical interest, because -in the overlap -- the combination of these senses of being gives rise to further relevant distinctions. For instance, the presence of the distinction between actuality and potentiality (4) in the sphere of being as true leads to a distinction between real possibility and veritative possibility, avoiding that this sense be confused with the mere logical possibility of late Scholasticism.

Keeping this in mind, we proceed now to the basic grouping together of these senses of being: while (1) and (2) refer to being in propositions, (3) and (4) signify being in reality. Aristotle himself provides a foothold for this kind of global discriminations, when he points out that only these last two senses of being form part of being qua being as the object of metaphysics:

Since the combinations and separation exists in thought and not in things, and this sense of being is different from the proper senses (since thought attaches or detaches essence or quality or some other category), we may dismiss the accidental being and the being as true. For the cause for the one is indeterminate, and of the other an affection of thought; and both are connected with the remaining genus of 'being' and not indicate any other nature of being. Let us therefore dismiss them, and consider the causes and principles of being itself qua being"⁽¹¹⁾.

Now entia per accidens do not form part of the object of metaphysics and are not studied as such by any science, as they are so neither usually nor always and of necessity, but fortuitously instead. In fact accidental being is nothing more than what comes about⁽¹²⁾. It is a mere coincidence, a coincidental being. "There can be no speculation about it. This is shown by the fact that no science, wether it be practical, productive or speculative concerns itself with it"⁽¹³⁾.

Moreover, the task of the first science is not that of looking for the origins to being as true, but rather to the origins of exterior and determinated being⁽¹⁴⁾, i. e. of really existent substances. Unlike de case of coincidental being, one can undertake a scientific study of the structures to being as true: something done by logic, which looks into matters "regarding the truth"⁽¹⁵⁾. For as Aquinas says, "tota enim logica videtur esse de ente et non ente sic dicto"⁽¹⁶⁾.

Having got thus far, it would seem that we must now enter into a fog of ambiguity, for Aristotle -- followed by Aquinas in his Commentary- maintains in Book II of the Metaphysics that philosophy as such, the first philosophy, is correctly called the "science of truth". Because the end of theoretical science is the truth, and in practical science is the result worked. Aristotle states:

"For even when they are investigating how a thing is so, practical men study not the eternal principle but the relative and immediate application. But we cannot know the truth apart from the cause. Now every thing throug which a common quality is communicated to other things is itself of all those things in the highest degree possessed of that quality (e.g. fire is hottest, because it is the cause of heat in everything else); hence that also is most true which is for all subsequent things to be true. Therefore in every case the first principles of things must necessarily be true above everything else -- since they are not merely sometimes true, nor is anything the cause of their being, but they are the cause of the being of other things-, and so as each thing is in respect of being, so it is in respect of truth"⁽¹⁷⁾.

As Aertsen indicates, "this argument must have had a strong appeal to Thomas, for he makes use of it in his proofs for the existence of God and in the doctrine of creation. Metaphysics II is also fundamental for his view that there is an intrinsic connection between being and truth (...). Truth now appears not as an intramental mode of being but as having an ontological dimension. The two approaches taken by Thomas result in two basic conclusions about truth. The first aproach based on Aristotle's claim that truth is not in things but in the mind, results in the conclusion that 'being-as-true' falls outside the metaphysics. The second approach follows Aristotle's statement that there is the same disposition in being and in truth and results in a conception of truth as being (...). The crucial question is, of course, whether the two conceptions of truth are compatible"⁽¹⁸⁾.

And the answer, for my part, is clearly in the affirmative. Truth as being and being as true are two differents meanings of 'being'. The first of these -truth as being- corresponds to a particular modus significandi of ens, whose reference is co-extensive with being, while its sense adds something to it that obviously cannot be real, but which signals the rational relationship that each reality has with the intellect that can know it as intelligible, i. e. as true in itself. We are dealing hence with a term among those that would later be called transcendentia, transcendental properties of being. And as, according to Aquinas, a thing is intelligible in so far as it is in act, this meaning of being should be classified into the fourth group of the senses of being, that is, being as actuality and being as potentiality.

The second of these two meanings of 'being', that is to say, being as true does not have a trascendental character as it does not refer to every type of things but rather only to a very particular type, which is no longer to be found in exterior natures but only in the mind: true propositions. We are not longer before the truth of being, but rather the being of truth. As we already know, we are dealing with the second of the senses of being, i. e. being as true or esse ut verum.

The relationship between these two meanings of being is found in that of the grounding being present in the grounded, given that the truth that is in the mind -- so called logical truth -- is grounded in the internal transparency of being in as much as it is actualized, that is to say, in transcendental truth ⁽¹⁹⁾ .

Although only transcendental truth -- and not logical truth -- forms part of metaphysics' object, it would be a grave error to ignore logical truth, what Aristotle called 'being as true'. For amongst other things, we can easily fall into a confusion about proper being and being as true, especially when dealing with existence which, as we shall see, can mean either actus essendi, or esse ut verum, in propositions of an existential nature. In fact, such confusion has occurred at crucial junctures in history, in issues of the greatest ontological, even theological, relevance.

This is not of course the case of St Thomas. Because Aquinas makes constant use of this distinction, to which he usually refers when he affirms that "ens dupliciter dicitur". And this happens especially in matters that, due to his own conception of the world, Aristotle never got around to confronting such face-on.

Particular attention should be paid to a brief text from the Summa Theologiae, which stands out for its clarity and punch, included in the fourth article of question three of the Prima Pars, considered rightly by many commentators to be the key-stone of Thomist natural theology. We are considering none other than the locus solemnis in which Aquinas shows that in God essence and being (in the sense of existence) are identified.

In order to establish this identity, St Thomas brings to bear the most advanced aspects of his metaphysics of being as actuality. "Being -- he writes in the corpus of the article -- is the actuality of every form or nature, as goodness or humanity only signify in act in so far as they are. It follows then that being itself is compared with essence, which is distinct from it, as actuality is with potentiality. But as in God there is nothing that is potential, it follows that the essence is not distinct from being. And hence, his essence is his being"⁽²⁰⁾.

Whilst in all other realities, being as existence is really distinguished from the essence, this distinction cannot be applied to God, in whom essence and existence are identified.

But in the second objection of the same article the following difficulty arises: As Aquinas himself has set forth in the brief Introduction to this third question, we can know of God's existence (an sit), but we cannot know what he is (quid sit). Hence the existence of God is not the same thing as his essence.

In reply to this objection, Saint Thomas calls into play the very distinction between the existence which is placed in the level of being as true and the existence in proper and real sense: "Being is said in two ways (esse dupliciter dicitur): in one case it means the actuality of being (actus essendi); in the other it means the composition of a proposition, which the soul gets to when it joins the predicate to the subject (alio modo significat compositionem propositionis, quam anima adinvenit coniugans praedicatum subiecto). According to the first meaning of being, we cannot know the being of God, nor can we know his essence. But we can know it in the second meaning. Because we know that this proposition, which we form when we say 'God exists', is true (scimus enim quod haec propositio quam formamus de Deo, cum dicimus 'Deus est', vera est). And this we know by his effects"⁽²¹⁾.

The text surprises, because it places the existence of God, arrived at from the five ways, in a logical-semantic level, according to the sense of being as true (esse ut verum). As Inciarte has pointed out⁽²²⁾, to demonstrate the existence of God only answers the question as to whether God exists (an Deus est). To reply in the affirmative to this question only means that to something (existent) corresponds the predicate 'God'. We do not conclude, thus, that God is something, but rather that something is God; of which we do not even know exactly what to exist means for him. To demonstrate the existence of God does not amount to more, then, that to show that the proposition 'God exists' is true (Deum esse, verum est). As occurs in symbolic logic when one applies the existential quantifier to a propositional function, what we see here involves a given proposition; but not what happens with a determinated real being. With the proposition 'God exists' it so happens that this is true. And the existence affirmed in the proposition is signified by a predicate of the second level, a predicate of concepts, according to the terminology of Gottlob Frege. But we do not refer directly here to the real being of God, to his proper existence (esse proprium), something inalienable to him that constitutes his specific life, according to the sense of being that we use in a typically Aristotelian proposition like"vivere viventibus est esse". And it is in being in this last sense -- and only in this last sense -- that the Thomist thesis maintains that God's existence is really identical with his essence. In this way, the difficulty posed in the second objection is clearly resolved: there is no identity between the essence of God and the fact of his existence; and so the Thomist thesis does not infringe upon the situation of one who is homo viator, who knows that God exists, but who does not know how God himself really is.

Although this interpretation comes directly from the Thomistic text itself, it could seen to disappoint or at least raise a few eyebrows. Because it would seen to show that the result of the demonstration does not lead us to the real existence of God but to somewhat strange propositional existence instead, which is not what we were looking for; nor, of course, is it what the great run of people -- and even some analytical philosophers of recent times contrary to the Fregean conception⁽²³⁾ -- understand by the verb 'to exist'.

But such surprise is not justified. To see why, let us stop for a few moments to better consider the nature of this sense of being that Aristotle called on hôs alêthes and Saint Thomas ens ut verum. In the first place, we need to realice that this veritative being does not identify with intentional being: with the kind of being that objects have in our mind upon being known.

Returning to some previous observations, one could say that the difference between coincidental being and being as true lies in that the first one, from real things that happen to occur, establishes as a predicate this coincidence ad instar entis; while the second one consists in the intellectual composition that conforms to the being of things. In being per accidens one goes from things to the mind; in being as true one heads towards things from the mind.

The reference of adequation, a constitutive dimension of being as true, does not establish itself from reality nor in every intentional act, for as Aristotle says, "(...) 'falsity' and 'truth' are not in things -- the good, for example, being true and the bad false -- but in thought; and with regard to simple concepts and essences there is no truth or falsity even in thought"⁽²⁴⁾. This allows us to already see that veritative being does not simply coincide with intentional being; because there are entities that possess esse intentionale, but to them we cannot attribute esse veritativum, as in the case of concepts captured by simple aprehension, that is to say, in the first intellectual operation.

Both being as true and intentional being correspond to intellectual operations that radically surpass all that is corporeal or animal⁽²⁵⁾. But intentional being is proper to the cognitive species and is part of the self sane life of the living being for whom their intellection is their life. With being as true, however, its exclusive seat is in judgements, but not only in so far as these are operations of an intelligent life form, but also and above all in so far as in them there is an adequation with natural reality, that is to say, truth. Thomas Aquinas, as is well known, developed this doctrine well beyond the point where Aristotle had left it, especially on the aspects concerning the peculiar reflexion which, together with adequation, is the very essence of human truth.

Nor can a precipitated identification be established between veritative being and what is called logical being, that is to say, the existence possessed by secundae intentiones, according to the scholastic terminology. Given that second intentions possess only a being of reason, they constitute one of the classic types of entia rationis, which are no more than objectivizations in the immanence of logos, "pure objects", following the denomination of Antonio Millán-Puelles in his fundamental book The Theory of the Pure Object⁽²⁶⁾ . Whereas being as true is not limited to its mental presence, rather, it refers to reality, given that it is in the truth of the proposition in which it appears, in its adequation with the things it deals with. For, as Aristotle indicates,

"the terms 'being' and 'not-being' are used not only with reference to the types of predicación, and to potentiality and actuality, or non-potentiality and non-actuality, of these types, but also to denote truth and falsity. This depends, in the case of the objects, upon their being united or divided; so that he who thinks that what is divided is divided, or that what is united is united, is right; while he whose thought is contrary to the real condition of the objects is in error. Then when do what we call truth or falsity exist or not exist? (...). It is not because we are right in thinking that you are white that you are white; it is because you are white that we are right in saying so"⁽²⁷⁾.

Returning to the Thomistic text about the existence of God, after this somewhat more technical digression, we can now see that upon saying that the proposition 'God exists' is true, we are not maintaining that God should have a merely intentional being, limited to thought reality. Hence, contrary to what Aertsens seems to suggest, it is not an "intramental mode of being" . In the case of the five Thomistic ways, the result of the demonstration -- even with this apparently restrictive interpretation -- is that there really is something that we call 'God', that God really exists, and not only in our way of thinking or speaking. Ex eius effectibus, from his effects, and by different paths, we come to know that the statement 'God exists' is true, which is exactly the same a s knowing that God exists. For, as Aquinas says in his Commentary on Book V of the Metaphysics, "cum enim dicimus aliquid esse, significamus propositionem esse veram"⁽²⁸⁾.

From the existential viewpoint, thus, our interpretation does not restrict in any way the a posteriori demonstration of the existence of God. What the distinction between esse ut verum and actus essendi highlights is that what we have arrived it at in the demonstration is not the proper being of God, but only the pronouncement of the existence of that reality which people of all religions and cultures call 'God'. The word 'God', despite the role it plays in the text from the Summa as subject, and Aquinas thinks here so, is not a proper noun from a logical point of view, but rather a predicate, that means a nature in the classic sense or a concept (Begriff) in a Fregean sense; a concept of which is said that there is an individual that falls under it. And hence, to say that "there are many gods" is false, but not absurd.

Taken in this way, existence is, according to the famous declaration of Immanuel Kant, "not a real predicate, not the concept of something that can be added to the concept of a thing"⁽²⁹⁾. But this thesis was not a discovery of Frege, nor was it from Kant. As we are now seeing, one finds it in Aquinas and one could even rake it out of Aristotle, when in Book IV of the Metaphysics he says that "existent man" and "one man" and "man" are de same thing ⁽³⁰⁾. Which means that neither 'to exist' not 'to be one' add to the definition of man any real or essentian determinations. And this means that neither existence nor unity are real, essential predicates. Let it be said in passing that Arthur Schopenhauer had already taken note of this when he said that in this text Aristotle has anticipated the Kantian criticism of the ontological proof of God's existence. A fact remembered by Elisabeth Anscombe and Peter Geach, Professor Geach having done so in direct connection with Thomas Aquinas⁽³¹⁾.

The advantage that Aristotle and, moreso, that Aquinas, enjoyed over the Kantian approach which predominates in contemporary linguistic analysis, is that, in addition to this sense of existence, which is signified in the expression "there is" -- the es-gibt-Existenz of Frege --, they also recognise another sense of being as existence, which is the very act of being proper to each thing. What is crucial to the fate of metaphysics, having been made problematic by the Kantian and logical-positivist approaches.

We can now make reference to something that was already implicit in all that has been said so far: that the distinction between veritative existence and being as actuality is not to be confused with the real distinction between esse and essentia, that is to say, with the genuine Thomistic distinctio realis, whose speculative relevance is even greater. It is quite significative, and even curious, that Aquinas should use both distinctions, without confusing them, in the same article of the Summa Theologiae that we are looking at. The real distinction between actus essendi and potentia essendi is the conceptual key to the argument put forward in the corpus of this forth article of the first question. While the distincion between esse ut verum and actus essendi is the tool with which Aquinas resolves the second objection made therein. But he even applies this second distinction to God, rigth after having demonstrated that in him the first distinction does not apply.

In the thougt of St Thomas Aquinas, the distinction between existence as propositional predicate and as act of being, is succintly put in two cases, the one been metaphysically the antithesis of the other, but which coincide in their logical expression: the affirmation of God's existence -- as we have just seen -- and the affirmations of the existence of privations, as it appears in a highly revealing text from the Commentary to the Sentences, whose relevance has been stressed by Professor Christopher Martin:

"Being is said in many ways. For in one way we speak of being as divided into the ten genus. And in this sense, being means something that exists in nature: be it a substance, like man, or be it an accident like colour. Another sense of being is that which points to the truth of a proposition: because when one says that an affirmation is true, it means that what is signified to so be, exists.; and when dealing with a negation, it means that what is not exist. And this sense of being signifies the composition that the intellect which composes and divides arrives at. Now all that is called being in the first sense is also being in agreement with the second way. Because all that has natural being in things can be signified as existing by means of an affirmative propositiom; as when one says that 'colour exists' or that 'man exists'. However, not all that is being in accordance with the second way is being according to the first way. Because with regard to privation as is the case with blindness, one forms a proposition in the affirmative, when one says 'blindness exists". But blindness is not something that pertains to the nature of things, but is rather a removal from being. And in this way one says that privations are beings in accordance with the second way but not according to the first way. Because being is predicated in a different manner in each of the two ways. According to the first way it is a substantial predicate and is concerned with the question as to what a thing is (ad quaestionem quid est). But according to the second way it is an accidental predicate, as the Commentator says, and pertains to the question as to wether a thing exists (ad quaestionem an est)"⁽³²⁾.

This coincidence -- paradoxical but rigorous -- of the logical form according to which we express the existence of God just as much as the existence of privations is grounded in both cases being, so to speak, limit cases of the graduated possession of being. Neither 'is' -- in the sense of 'exists' -- in which we affirm the existence of a privation, nor 'is' with which we affirm the existence of God, directly express an esse proprium: because the privation does not have proper being and the being proper to God -- with which himself is identified -- is unknown to us. Such coincidence underlines -as suggested in the text just quoted -- the non complete correspondence of being de dicto with being de re, as the greater amplitude of the first with respect to the second.

Aquinas refers to both cases -- with explicit mention of Aristotle, in the same logical context and without a solution of continuity -- in a text from the Quaestio disputata De Potentia:

"'Ens' and 'esse' are said in two ways, as Aristotle made clear in Bokk V of the Metaphysics. For at times it can mean the essence of the thing, or the act of being; whereas at others it refers to the truth of the propositions, concerning even to things that do not have being; as when we say that 'blindness exists' because it is true that a man is blind. When St Joh Damascenus says that the being of God is manifest to us, he takes the meaning of being in its second sense and not in the first one. For in the first sense, the being of God is identified with his substance; and as his substance is unknown to us, so too his being is also unknown to us. In the second sense, on the other hand, we know that God exists, because we can conceive this proposition in our intelligence, starting from his effects"⁽³³⁾.

The issue of the type of being that correspons to privations takes on special metaphysical ant theological relevance when we look at the problem of evil. As Aquinas says in the Prima pars of the Summa Theologiae, question 48, article 2, it is evident that there is evil in things. But one could object that evil is a privation, a mere non-being, and that it is impossible, hence, for evil to exist in things because non-being does not exist.⁽³⁴⁾ In order to respond to this difficulty, Thomas draws once more from the already alluded to distinction. 'To be', he reminds us, is taken in two senses. With the first, it means the entity of the thing (entitas rei); an this is the sense according to which the entity is declined analogically into ten predicaments o categories. The second sense (itsel univocal in meaning), in which being is taken, means the truth of a proposition (veritas propositionis), which is in the composition and has as its distinctive sign the verb 'is'. This is the sense of being to which corresponds the question an est, i. e., to wether something exist or not. In this second mode we can say with truth that 'there is evil', that 'evil exists'. And Aquinas could conclude that, by not attending to the double meaning of the verb 'to be', there were some who, when saying that things are evil, or that evil is in things, believed that evil was actually some thing⁽³⁵⁾.

As we are presently seeing, the distinction between the different senses of being always has the effect -- in one way or another -- of overcoming reification in metaphysical problems. This is an unmistakeable sign that Aquinas did not limit himself to take from Aristotle a handy conceptual tool for solving linguistic puzzles, but rather that this technical recourse was at the service of an intellectual dynamic that moved his metaphysics progressively from contents to acts: from ens per accidens to ens per se; from esse ut verum to esse proprium; from accidents to substance; and, in short, from form to act, until reaching pure Actuality, God himself, in whom all content is transcended, reaching toward the supreme perfection of a praxis teleia that referes to itself, because it is a noesis noeseos noesis. Is the substantive Act, which Aquinas called Ipsum esse subsistens. In such a way that the negative aspect which the Thomistic essential theology appeared to adopt at the start, does not in any way present the agnostic bias acquired in Maimonides. Rather it is ordained towards a knowledge of the divine essence which is purified from all adhesion to mundane realities that are proper to the differente types of anthropomorphism.

As Mercedes Rubio has pointed out, "Thomas Aquinas appreciated and shared Maimonides' commitment to physical reality and undertook the task of finding a way to the knowledge of God taking the world as startirng point⁽³⁶⁾. Strikingly, after taking the same route, each one eventually reaches opposite conclusions regarding the possibility of the knowledge of God. In fact, according to Aquinas, the human intellect is able to apprehend being by nature. This aprehension, which he calls ratio, would enable the crossing from the ontological level (reality) to the gnoseological one (knowledge) and back (knowledge of that reality). The ratio consists of the intellectual content of an apprehension without the limitations inherent to a concept. At the linguistic level, concludes Mercedes Rubio, Aquinas expplains the 'hinge' between reality and knowledge with the distinction of the two senses of the word being: being as real (ontological being), and being as truth (veritative or gnoseological being)"⁽³⁷⁾.

It is evident that this Thomistic recourse to the distinction between the different meanings of being, and especially to the distinction between being as true and proper being, is not limited to metaphysics, within which natural theology is included, but that it extends quite naturally to theology in its strict sense, that is to say, to the doctrine of Christian faith.

Aquinas makes use of this distinction when dealing with theological problems of the firs importance. In the IX of the Quaestiones Quodlibetales, for instance, he try to demonstrate that in Christ there one only esse substantiale. The fourth objection raises the following difficulty: one can attribute esse to all that one can ask about as existing or not (an est); now then, one can ask if the human nature of Crist exists (and the answer is in the affirmative, contrary to the monophysite heresy). Hence the human nature of Christ -- as well as the divine one -- has an esse proprium in Christ, and thus there is in Him a double esse. In reply to this objection, Aquinas limits himself to invalidate it by mentioning the meaning of being employed by the objector, which is not relevant to the context. And in making this allegation, he compares once more the case of God with the privations: "Obiectio illa procedit de 'esse' quod in actu animae consistit; quia an est, etiam de caecitate quaeri potest"⁽³⁸⁾.

In the corpus of the article, Aquinas develops the doctrine we are now familiar with: 'Being' is said in two ways, in accordance whith what Aristotle had indicated in Book V of the Metaphysics. According to one of them, it is the verbal copula that signifies the composition of any sentence made by the mind. Hence, the esse to which we refer in this first sense is not something in the nature of things, but only in the act of mind that composes and divides; and such esse is attributed to all that can form a proposition, be it being or be it privation of being (or, as in the case of the human nature of Christ, to somethig that is not a suppositum substantiale, but rather that by which -- quo -- Christ is truly man). According to the other way, 'being' is said as act of the entity in so much as it is an entity, that is to say, as that by which one calls something entity in act in the nature of things; and in this second sense, the esse is not attributed to other than the things contained in the ten predicaments or categories (as with the person -- which is divine -- of Christ, whose esse substantiale is the only one that Crist has)⁽³⁹⁾.

The Thomist argument in the treatise De Verbo Incarnato as much as in the treatise De Trinitate would not be viable without the continuous use of the distinctions between the different senses of being, just as Aquinas found them in an Aristotle who, for historical and religious reasons, was obviously quite removed from such concerns. Certainly, as we have seen, his own metaphysics of being as actuality and his biblical and Christian theology move Aquinas to render an original argument from the Aristotelian linguistic and conceptual analysis, without deviating from such in any way. The study of the philosophia perennis -of philosophy as such -- places us in an ambience of thought that is miles away from multiculturalism.

1. Metaph., VII, 1028 b 4 (trans. The Loeb Classical Library).

2. Metaph., IV, 1, 1003 a 21-22.

3. Cf. Metaph., III, 998 b 22-27.

4. Cf. HEIDEGGER, M.: Nietzsche II, Pfullingen, Neske, 1961, p. 211.

5. Metaph., IV, 2, 1003 a 33; Metaph. VII, 1028 a 10.

6. Cf. CARNAP, R.: "Ueberwindung der Metaphysik durch logische Analyse der Sprache". Erkenntnis, II, 1932, pp. 219-241.

7. Metaph., V, 7, 1017 a 7, 22-24, 31-33; 1017 a 35 - 1017 b 2.

8. Metaph., VI, 2, 1026 a 33 - 1026 b 2.

9. BRENTANO, F.: Von der mannigfachen Bedeutung des Sienden nach Aristoteles. Hildesheim, Olms, 1960.

10. Cf. In V Metaphysicorum, lect. 9, nn. 885-897.

11. Metaph, XI, 8, 1064 b 30 - 1065 a 6.

12. Cf. Metaph., XI, 8, 1064 b 30 -1065 a 6.

13. Metaph., VI, 2, 1026 b 3-5.

14. Cf. Metaph., XI, 8, 1065 a 21-24.

15. Cf. Metaph., IV, 3, 1005 b 3; BRENTANO, op. cit., p. 30.

16. In VI Metaphysicorum, lect. 4, n. 1223.

17. Metaph., II, 1, 993 b 20-30.

18. AERTSEN, J. A.: Medieval Philosophy and the Transcendentals. The Case of Thomas Aquinas. Leiden, E. J. Brill, 1996, pp. 251-252.

19. "Veritas fundatur in esse rei, magis quam in quidditate, sicut et nomen entis ab esse imponitur". In I Sententiarum, d. 19, q. 5. a. 1.

20. Summa Theologiae, I, q. 3, a. 4c

21. "Esse dupliciter dicitur: uno modo significat actum essendi; alio modo significat compositionem propositionis, quam anima adinvenit coniugans praedicatum subiecto. Primo igitur modo accipiendo esse, non possumus scire esse Dei, sicut nec eius essentiam: sed solum secundo modo. Scimus enim quod haec propositio quam formamus de Deo, cum dicimus 'Deus est' vera est. Et hoc scimus ex eius effectibus". Summa Theologiae, I, q. 3, a. 4, ad 2.

22. Cf. INCIARTE, F.: El reto del positivismo lógico. Madrid, Rialp, 1974, pp. 134-135.

23. Cf. KNUUTTILA, S. and HINTIKKA, J. (eds.): The Logic of Being. Dordrecht, Reidel, 1986.

24. Metaph., VI, 4, 1027 b 25-28.

25. Cf. INCIARTE, F.: "Ser veritativo y ser existencial". Anuario filosófico, XIII/2, 1980, pp. 22-23.

26. MILLÁN-PUELLES, A.: The Theory of the Pure Object. Heidelberg, Universitätsverlag C. Winter, 1996.

27. Metaph., IX, 10, 1051 a 34 - 1051 b 9.

28. In V Metaphysicorum, lect. 9, n. 895; cf. n. 896.

29. Kritik der reinen Vernunft, A 598, B 627.

30. Cf. Metaph., IV, 2, 1003 b 26-27.

31. Cf. INCIARTE, F.: "La importancia de la unión predicado-sujeto en la doctrina trinitaria de Tomás de Aquino". Scripta theologica, XII/3, 1980, p. 875.

32. In I Sententiarum, d. 34, q. 1, a. 1. Christopher Martin me hizo reparar en la importancia de este texto. Cf. In VI Metaphysicorum, lect. 4, n. 1223; BRENTANO, op. cit., p.34.

33. De Potentia, q. 9, a. 2, ad 1. Cf. Contra Gentiles, III, c. 9, a. 6.

34. Summa Theologiae, I, q. 48, a. 2, obiect. 2.

35. Summa Theologiae, I, q.48, a.2, ad 2.

36. Cf. HARVEY, W. Z.: Physics and Metaphysics in Hasdai Crescas. Amsterdam, Amsterdam Studies in Jewish Thougt, 1998, p. 76; DEWAN, L.: "St. Thomas, Physics, and the Principle of Metaphysics". The Thomist, 61, 1997, pp. 549-566.

37. RUBIO, M.: "Maimonides and Aquinas on the Knowledge of God". Pro manuscripto, Jerusalem, 2000, p.3.

38. Quodlibetum IX, q. 2, a. 3, ad 4.

39. "Esse dupliciter dicitur, ut patet per Philosophum in V Metaph.(…). Uno modo, secundum quod est copula verbalis significans compositionen cuiuslibet enuntiationis quam animam facit: unde hoc esse non est aliquid in rerum natura, sed tantum in actu animae componentis et dividentis. Et sic esse attribuitur omni ei de quo potest propositio formari, sive sit ens, sive privatio entis; dicimus enim caecitatem esse. Alio modo dicitur actus entis in quantum est ens, idest quod denominatur aliquid ens actu in natura. Est sic esse non attribuitur nisi rebus ipsis quae in decem generibus continentur; unde ens a tali esse dictum per decem genera dividitur (…). Quia in Christo ponimus unam rem subsistentem tantum, ad cuius integritatem concurrit etiam humanitas, quia unum suppositum est utriusque naturae; ideo oportet dicere quod esse substantiale, quod proprie attribuitur supposito, in Christo est unum tantum; habet autem unitatem ex ipso supposito, et non ex naturis". Quodlibetum IX, q. 2, a. 3. Cf. ANSCOMBE, G. E. M. and GEACH, P., Three Philosophers, p. 90.