D: Objections to the Natural Science Approach to Meta-Science
1) Thomist Objections
In Chapter II seven current interpretations of Aquinas were listed: (1) Essentialist orConceptualist, (2) Transcendental, (3) Existential, (4) Phenomenological, (5) Analytic,  (6) Semiotic, and (7) Aristotelian Thomisms. Of these the Analytic, and Semiotic views have up to now little concerned themselves with the question of the subject, or more properly, as I have shown previously, the object of Meta-Science. The Transcendental Thomists differ so much epistemologically from the Existential and Aristotelian positions that I will leave their position, including its nuanced exposition by W. Norris Clarke, S.J., to Chapter VIII that treats of epistemology. The Phenomenological view seems to be reconcilable either to an Existential or an Aristotelian position. Therefore, here I need discuss only the objections of the Conceptualist or Essentialist and Existentialist Thomist to what I am calling the Aristotelian interpretation. I am not concerned with the much-debated questions about whether Aquinas' reading of Aristotle is historically correct. In calling the view I favor the "Aristotelian approach" I claim nothing more than that Aquinas attributes it to Aristotle. Nor am I primarily interested in defending Aquinas himself or settling arguments as to what he personally thought. My concern is only to show the validity of Meta-Science in view of its present bad repute. Hence I refer to historical and textual questions only when this is necessary to explain the objective arguments.
The Conceptualist or Essentialist position is now generally considered outmoded and my friend Lawrence Dewan, O.P. would not accept any such label for the views he has recently expressed in criticism of my position.  Yet, since he avoids the kind of arguments used by the Existentials influenced by Étienne Gilson against the Essentialists, I will treat his arguments as an up-dated example of the Essentialist approach. I will also pass over his argument ex silentio in which he points out that even in the texts on which the Aristotelian position relies, Aquinas does not seem explicitly to state that position but generally discusses all philosophical questions as a meta-scientist. I have already pointed out in Chapter II that St. Thomas, like medievals generally, had no reason to defend the validity of Meta-Science (metaphysics) against materialism. Hence nothing can be concluded from the fact that Aquinas usually simply assumes the validity of Meta-Science or from his habit of discussing questions from for the broadest possible perspective, the meta-scientific attitude.
Dewan relies chiefly on two important philosophical arguments: (1) Meta-physics, as Aquinas certainly maintains, proves the first principals of all the other sciences, including those of natural science. Therefore, the establishment of the object of metaphysics must be independent of any demonstration from within natural science of the existence of immaterial causes.  (2) The proper object of the human intelligence, as Aquinas also certainly maintains, is ens, being. Being universally considered is the object of metaphysics not of the special sciences each of which deals only with a special kind of being. For example, natural science deals not with Being as Being but only with ens mobile, being as changeable.
As to the first of Dewan's arguments, it should be recalled that Aquinas himself takes up much the same argument as an objection in the Commentary on Boethius' 'De Trinitate' q. 5, a. 1, and provides an answer. 
Objection 9: That science on which others depend must be prior to them. Now all other sciences depend on divine science because it is its business to prove their principles. Therefore Boethius should have placed divine science before the others.
Reply: Although divine science is by nature the first of all the sciences, with respect to us the other sciences come before it. For, as Avicenna says, the position of this science is that it be learned after the natural sciences, which explain many things used by metaphysics, such as generation, corruption, motion, and the like. It should also be learned after mathematics, because to know the separate substances metaphysics has to know the number and disposition of the heavenly spheres, and this is impossible without astronomy, which presupposes the whole of mathematics. Other sciences, such as music, ethics, and the like contribute to its fullness of perfection. [Aquinas' paraphrase of Avicenna ends here and he continues his own comment]. Nor is there necessarily a vicious circle because metaphysics presupposes conclusions proved in the other sciences while it itself proves their principles. For the principles that another science (such as natural philosophy) takes from First Philosophy do not prove the points which the first philosopher takes from the natural philosopher. But they are proved through other self-evident principles. Similarly since the first philosopher does not prove the principles he gives the natural philosopher by principles he receives from him, but by other self-evident principles there is no vicious circle in their definitions. Moreover, the sensible effects on which the demonstrations of natural science are based are more evident to us in the beginning. But when we come to know the first causes through them, these causes will reveal to us the reason for the effects, from which they were proved by a demonstration quia [i. e. of the fact but not of the cause of the fact, i. e., a demonstration a posteriori not a priori]. Thus there is no difficulty in calling metaphysics "First Philosophy" yet admitting that it presupposes conclusions of natural science because these are better known to us in via inventions although metaphysics reflects on all the lower sciences in via resolutionis.
I have argued in Chapter IV that such first principles as that of Non-Contradiction and of Causality are shown in via inventions to be directly evident principles only as principles of natural science restricted to its scope as a science of the sensible. Only when natural science has proved that immaterial being exists can these principles be extended analogically to become universal principles common to all the sciences. Thus if taken in this universal sense they are first principles of all the sciences and are proved by Meta-Science in via resolutions. It remains true, therefore, that as Aristotle and Aquinas say, 
If there is no substance other than those that exist in a way that natural substances do, with which the philosophy of nature deals, the philosophy of nature will be the first discipline. But if there is some immobile substance this will not be natural substance, and therefore the philosophy that considers this kind of substance will be First Philosophy.
Thus this first argument of Dewan fails because it assumes that natural science is based on principles that are known in their meta-scientific extension when in fact he has not shown that Meta-Science is needed to know these principles. Since for Aquinas, just as for Aristotle, every science is based on evident first principles why does natural science need a Meta-Science to makes its own first principles evident, especially since, for Aquinas, natural science is more directly based on sense experience than any other science. 
Dewan's second argument concerns the proper object of the human intelligence. He says, 
Thomas never says to my knowledge, and never would say, in my judgment, that the proper object of the human intellect is ens mobile. When he needs to underline the humble beginnings of human intellection, he uses such a formula as "ens vel verum, consideratum in rebus materialibus," that is "a being" or "the true," considered in material things." (S. Th. I., q.87, a. 3 ad 1). This is a formula that, while indicating the mode of being that is the connatural object of the human intellect, preserves the metaphysical starting point from confusion with the notions proper to physical science.
In Chapter III A2 I discussed the material and formal objects of human intelligence and the difference between its formal object quod and quo and I need not repeat this here. I showed that it is true that what is intelligible to us in real objects (objectum formale quod) must always be their actuality or being. Otherwise we would be studying some supposedly possible essence, although we cannot know that an essence is possible without first knowing of some real instance of such a being. Thus it is correct to say that every science is about being and what is true of it. But meta-scientific being in the sense of Being as it extends to immaterial as well as material beings is not immediately evident to us. Hence we cannot begin our thinking as meta-scientists, as Dewan claims. It is only through following the order of the sciences presented by Aquinas in the Commentary on Boethius' 'De Trinitate' that the terms used in the principles of the different sciences become clear enough to us through a judgment that the first principles proper to each science can be said to be evident simply from their terms. This is supremely true of Meta-Science that enjoys the highest degree of immateriality and thus of intelligibility in itself, but is most obscure to us in our human way of knowing.
Dewan's real concern appears in the second part of his article, "Thomas on the Formation of the Educated Mind" where he quotes the beautiful text In Eth. VI, lect. 5, n. 1181 that shows why Meta-Science is the architectonic science (the very point to which the present book is dedicated) and again cites Aquinas:
"As that one is wise in some art is most sure in that act, so the science that is wisdom in most absolute sense is the most certain among all the sciences, in that it attains to the first principles of [all] beings which in themselves are most knowable, although some of them, namely immaterial [beings] are less known quoad nos. But the most universal principles are also most known quoad nos, as they are what pertains to Being as Being, whose cognition pertains to wisdom, as is said in Metaphysics IV, 6-8, In Met. Lect 7, nn .700-719.
On this Dewan says, 
Though some of these principles are less known to us than other things, nevertheless this claim is well founded, inasmuch as the most universal principles, pertaining to being as being, are both best known in themselves and best known to us [my italics and my distinction: best known to us in their restricted physical form, but not in the extended metaphysical form in which they are best known in themselves]. "And these pertain to metaphysics. Obviously, if the first principles, as first known, were at first limited to corporeal being as corporeal, they would not be known as they pertain to metaphysics. Thomas sees the principles, precisely as known first of all and to all, as having the properly metaphysical character. This does not make the beginner a finished metaphysician, but it does mean that the principles of metaphysics are precisely those very first-known principles, not some newly constructed conception of being resulting from the study of physics. If we did not start with metaphysical principles, no particular science would ever provide them."
He refers to S. Th., I-II q. 89, a. 6 ad 3 in which Aquinas indicates that in its earliest truly human acts the child must have some knowledge of the ultimate end in view of which every moral decision must be made, and of course in fact this end is union with God, to which Dewan remarks,  "Already, when one undertakes one's first moral act, one has knowledge of God. However, it does not have scientific perfection" [italics added]. Thomists, however, have generally recognized that this does not mean that to perform a moral act anyone, including a child, must have an explicit, formal knowledge that union with God is in fact the true ultimate end that alone constitutes human happiness. But this presents no difficulty for the Aristotelian approach to Meta-Science of which Dewan disapproves. St. Thomas teaches we have "a natural desire to see God," but that this desire demands the perfect beatitude, possible only in the order of grace, is not evident to reason. Indeed it is not evident to reason that such beatitude is even possible for finite beings. All that reason can show is that we are capax Dei since intelligence, whether human or angelic, has dynamic openness to receive truth.
Indeed Dewan's qualification, "However, it does not have scientific perfection" nullifies his argument, since it admits that the "knowledge of God" to which he refers is merely implicit and virtual. Therefore we must still ask by what stages of thought one comes to a scientific, critical knowledge of the object of Meta-Science as distinct from that of any of the specials sciences. Dewan, as far as I read him, provides no answer.
The Existential Thomists, like the Essentialists, argue that a valid Meta-Science need not presuppose the demonstration of the existence of immaterial substances, but they reach the same conclusion as Dewan but by a different route. They do not accept as Aquinas' own view that which he states without criticism in his Commentary on Aristotle's Metaphysics: :
For the ancients did not think any substance existed other than corporeal mobile substance about which the natural scientist is concerned. And therefore it was believed that only natural scientists treated of the totality of nature and consequently of being, even of the first beings. But this is false since there is a certain science that is superior to natural science, for nature, that is, those natural things that have an intrinsic principle of motion, is itself only one genus of universal being. For not all being is of this kind, since it is proved in Physics VIII that there exists some immobile being [italics added]. This immobile being is superior to and nobler than the mobile being that natural science studies. And since the consideration of ens commune pertains to that [superior] science, to which [also] pertains the consideration of the first being, it will also be for it to consider study its common principles. For natural science is a part of philosophy, but it is not First Philosophy which considers ens commune, and whatever pertains to this kind of being.
Gilson adopted the Existential approach because he was convinced of the originality of Aquinas on the object of Meta-Science as esse or existential act as against Aristotle's conception of Meta-Science.  Thus he says, 
In fact, everything goes as if, when he [Aristotle] speaks of being, he never thought of existence. He does not reject it; he completely overlooks it. We should, therefore look elsewhere for what he considers as actual reality. "Among the many actual meanings of being, " Aristotle says, "the first is the one where it means that which is and where it signifies the substance. " [Meta. Z, 1, 1028 a13]. In others words, the is of the thing is the what of the thing, not the fact that it exists, but that which the thing is and which makes it a substance. This by no means signifies that Aristotle is not interested in the existence or non-existence of what he is talking about. On the contrary, everybody knows that, in his philosophy, the first question to be asked about any possible subject of investigation is, does it exist? But the answer is a short and final one. Once evidenced by sense or concluded by rational argumentation, existence is tacitly dismissed. For, indeed, if the thing does not exist, there is nothing more to say; if, on the contrary, it exists, we should certainly say something about it, but solely about that which it is, not about its existence, which can now be taken for granted. This is why existence, a mere prerequisite to being, plays no part in its structure. The true Aristotelian name for being is substance, which is itself identical with what being is [Meta., ibid. 1028b2 8].
Would it not be more correct to read Aristotle as saying that "being primarily is existing substance" so that for him (and for Aquinas) to say that Meta-Science is about "Being as Being," and hence primarily about existing substance, rather than simply about its act of esse? How can one speak of the act of something, without saying what that something is that is made actual by its esse? Thus Gilson, in spite of his important study of Scotus whom he compares unfavorably to Aquinas, comes, like Dewan, perilously close to the position that David Burrell describes as follows: 
So Scotus presents us with a First Philosophy which acts as a foundation science, elucidating the elementary component of any other kind of knowledge. The component is the most common notion of all hence the ground of predication; it is the most simple and hence the most certain notion and by rights it is the first known of all.
What is relevant in this historical thesis for our philosophical purposes here is only that it raises the question of what exactly it means to say that Meta-Science deals with "to be" (esse), as Gilson and his school so much insist. Once Question 1, "Does it exist?" is answered affirmatively, what more in fact remains to be said about that existent than to ask and answer Questions 2-4 about its essence and its properties? Gilson obviously thinks that much remains to be said, but he does not tell us what that might be, or what questions he would ask about esse that are not questions about what kind of a being is actualized by this esse.
Surely Meta-Science could not be called a wisdom, or even a science, if it amounted to nothing more than enthusiastic declarations that "Being is Being"! Certainly it is true, as Aquinas shows, that existence is the act of essence. As act is causally correlative to the potency of essence, esse causes the essence to be and the essence as the correlative potency of esse causally limits esse. When Gilson asserts that "The true Aristotelian name for being is substance, which is itself identical with what being is" he seems to forget that for Aristotle "substance is that which has independent existence." Hence it is quite correct to say that the study of "to be" is the study of substance as such, Being qua Being, along with any proper accidents it may have which are dependent on it for their existence and hence are Being in various different senses.
In the First Cause alone esse is identical with its nature or essence, because it is that very nature or essence to exist necessarily. Every effect of the First Cause by reason of the contingency of its nature or essence must receive its existence from an efficient cause other than itself, either directly from the First Cause or mediately through causes that can cause only when caused. Hence the existence of all beings other than their Creator is really distinct from their essences, yet this existence, esse, or actuality is nothing other than the various acts of their correlative essences. Hence nothing more can be known about an existent being as it is analogically included in Common Being, the subject of Meta-Science than its essence and its proper efficient cause. Thus it is puzzling that Gilson should complain because Aristotle after finding an answer to the question "Does it exist?" occupied himself with exploring what that existent substance was and what caused it to be what it was, rather than to trying to further explore an undefined esse that can have no meaning apart from the essences of which it is the act.
Indeed it is the contingency of the essence of changeable things with its consequent real distinction from its esse that is the basis of Aristotle's demonstration that the efficient cause of that existence must ultimately be immaterial. Thus far from neglecting esse the use of the demonstration of immaterial causes for material effects manifests its primary importance. Moreover, a Meta-Science established in this manner will not content itself with declaring the primacy of esse, but by exploring every kind (essence) of being in its different ways of being in act and the various relations between these ways of being to each other, it will seek to enrich the initial zero of "Being as Being" by giving it positive but diverse content. 
George Klubertanz, S.J., Leo Sweeney, and many others have also followed the Gilsonian version of Existential Thomism. It also ultimately gained the support of Jacques Maritain. His position, however, has an interesting relation to that of the Transcendental Thomists and in Chapter VIII I will discuss its epistemological significance for Maritain's important insights on "connatural knowledge." Since, however, the most thorough recent exposition of the Gilsonian view is that of John F. Wippel, it is in his formulation that I will discuss it here. 
Some Existentials reject the Aristotelian approach to Meta-Science outright because they think the demonstration in Physics VIII of the Prime Mover in fact proves nothing more than the existence of an ensouled outer celestial sphere and not God as the First Cause.  The Aristotelian approach, as we have seen, requires nothing more for the establishment of the validity and independence of Meta-Science than a proof that some being is immaterial. The positive essence of this immaterial being is for Meta-Science to explore. Wippel is willing to grant that this proof may be valid.  Yet he raises difficulties about it, minimizes its importance, and contends that Aquinas provided a better way of establishing Meta-Science.  He and others of this school generally rely on Gilson's reading of the history of medieval thought according to which Aquinas' commentaries on Aristotle do not reflect his own views and hence seek, as Wippel puts it, to "reconstruct" a better view from texts that more certainly express Aquinas' personal views. 
Wippel sums up of his reconstruction of this supposedly superior and more authentically Thomistic view on the object of Meta-Science as follows:
That by reason of which something is recognized as enjoying being need not be identified with that by reason of which it enjoys this or that kind of being. Therefore, we may investigate one and the same physical and changing thing from different perspectives. We may study it insofar as it is material and mobile, or insofar as it is living, or insofar as it is quantified. But we may also study it insofar as it enjoys reality at all, i.e., insofar as it is a beingâ€¦Is this not to make metaphysics a science of the merely possible? Not at all. To examine something from the standpoint of being is to continue to apply to it the intelligible content contained in our primitive understanding of being as "that which is," As a result of separation we continue to recognize whatever we study in Meta-Science as enjoying being, or as an instance of "that which is." We do not abstract from this inclusion of existence in our primitive understanding of being when we apply separation to it. We rather judge that the intelligible content in virtue of which we recognize any thing as being ("that which is") is not to be restricted to or identified with that intelligible content which we recognize it as being of this or that kind. Otherwise being could be one in kind.
But just what is this "intelligible content" of "that which is" other than the actuality of the different kinds of being that are analogically included in it, but way that are more different than alike? To avoid the circularity we have seen in Dewan's arguments, however, Wippel insists that 
[This] is not Thomas' distinction and composition of essence and an intrinsic existence principle (act of being) which is discovered through separation. Through separation one simply recognizes the legitimacy of investigating any thing in terms of its reality or as a being ("that which is") rather than from any other perspective. Investigation of the relationship between essence and existence (esse) can come later in the order of discovery, and presupposes that one has already discovered being as being.
Yet he does not say what the difference is between recognizing that material things are of the different kinds (essences) yet have esse in common and saying that their essence and existence are really distinct. The distinction that Wippel makes is between (1) a "primitive" awareness of being acquired simply by recognizing that, although sensible things differ greatly in kind or essence, they have existence in common, and (2) a fully developed grasp of the meaning of esse that is required for it to serve as the object of Meta-Science. This latter awareness of esse must be known not by the first operation of the human intelligence, simple apprehension, but by the second, judgment. Thus Aquinas in his Commentary on Boethius' 'De Trinitate,' q. 5, 3 contrasts the way that the object of metaphysics (Meta-Science) is known with the ways in which the objects of natural science and mathematics are known. 
We conclude that there are three kinds of distinction in the operation of the intellect. There is one through the operation of the intellect joining and dividing [componentis et dividentis] which is properly called separation; and this belong to divine science or metaphysics. There is another through the operation by which the quiddities [essences] of things are conceived which is the abstraction of form from sensible matter; and this belongs to mathematics. And there is a third through the same operation which is the abstraction of the universal from a particular; and this belongs to physics and to all the sciences in general, because science disregards accidental features and treats of necessary matters.
Louis Geiger, O.P. first brought this text of Aquinas about the judgment of separation that is somehow involved in establishing the object of Meta-Science into prominence in 1947.  He read it as supporting the natural science approach to Meta-Science that gave a better view of Aquinas' position on the distinction of the sciences than the classical view of Cajetan that distinguished them by "three degrees of abstraction. For Wippel and other Existential Thomists, however, this text is read as the chief textual support for their own position.
What point is Aquinas really making in this text? The reason for the distinctions he makes is that an abstraction cannot be valid unless what is abstracted can be separated in existence from that from which it is separated. This is the case in the first way in natural science that only separates essences from accidents and in a second way in mathematics that separates the accident of quantity from the other accidents, since it is prior to them in existence. On the contrary, however, although the esse of things that is the intelligibility under which things are studied in Meta-Science is really distinct from their essences, it cannot be separated from them in extra-mental reality. This is so because esse is nothing but the very actuality of things, their actus essendi. Thus esse cannot be validly known by abstraction but only by a judgment that the object of the science does in fact exist.
It should be noted, however-and this is often overlooked in citing this text-that Aquinas is not claiming that the objects of the sciences other than Meta-Science are validated simply by a first operation of the mind. The first principle of any real science, not just that of Meta-Science, must be asserted by a judgment of separation that judges on the basis of evidence (ultimately the evidence of the senses) that this object exists. Natural science and mathematics can judge that their objects somehow have real existence, because these are known by a legitimate abstraction from objects known to be real. Thus we can truly judge that the object of natural science, namely, changeable being really exists, although that science considers it apart from its accidental properties that are to be demonstrated of it and from its mere accidents. Similarly we truly judge that the object of mathematics exists because we consider quantity as it really exists in material substances, though we study it in abstraction as the first property of these substances. The object of Meta-Science, however, since it is the very actuality of all that exists, Being as Being, cannot be validly abstracted, since nothing real would remain.
Thus for Being in this inclusive meta-scientific sense to play its role as the first principle of an independent science, it must, like the subject of any science, be truly judged to exist. And if it is to be the first principle of an independent science it must somehow be evidently judged to be true simply from its terms. This does not mean that the first principles of every valid science (especially metaphysical principles, as Dewan claims) are immediately evident to every one. Mathematics is an independent science with first principles evidently true from their terms, but its axioms are not immediately evident to every student. It was the great achievement of the Greeks among all the world cultures to be able to formulate them precisely. The terms of first principles must be made evident by a process of abstraction or in some other manner and their reality must be grounded in some direct or indirect evidence. That is why St. Thomas in the Commentary on Boethius' 'De Trinitate' devotes so much attention to the "order of the sciences." Hence as regards Meta-Science, the ultimate science, we must ask how we can judge that Being as Being, in the sense proper to Meta-Science as an independent science, really exists, rather than an empty verbalism as so many modern philosophers claim.
Does Wippel answer this question? He first says, 
Just what does separation contribute to metaphysics or to our discovery of it subject? I would be considerably easier for us to answer this question if Thomas had devoted a full article to separation itself. Since he did not do so, we must base our interpretation on the few remarks he makes about it in [the Commentary on Boethius' 'De Trinitate.'] q. 5, a. 3.
I have previously granted that we have an "awareness" of being that enables us to answer Question 1, "Does it exist?" and that this answer already confusedly contains the answer to Question 2, "What is it?" Hence this awareness can be called "primitive" in contrast to an explicit answer about essence that answers Question 2 and thus makes clear that the "to be" of any contingent thing is not identical with the kind of thing it is. Thus, as Wippel says, we know that the act of esse is other than essence it actualizes, since we observe that different essences all have esse in common. We cannot, however, on this basis alone assert that this esse that is common to different kinds of material things is other than the actus essendi of material things.
Though some Existential Thomists have argued that natural science is only about the appearances of changeable things and not about their ontological being as such, this could be true only if they were considered merely as possible not as real. Wipple is firm in denying that metaphysics is about the merely possible.  In any case there cannot a real science about the merely possible, since possibility can be known only through what is actual. All real sciences first ask the question "Does it exist" and whatever they say about "What is it that exists" what is being considered is being as it has esse.
Therefore, in order to get beyond this primitive awareness of esse, Wippel has to argue that the judgment of separation specific to metaphysics renders this awareness "unrestricted" to merely material being, or as Wippel sometimes says, "negative" to material and immaterial being alike. Yet if the object of Meta-Science (metaphysics) is ens commune it cannot be "neutral" to material and immaterial being, since, as Wippel certainly admits, it positively includes them both. The statement that ens commune is "neutral" brings us much too close to the Scotistic univocal concept of being as "that which is merely not nothing." More correctly, Wippel also says that metaphysical Being is "unrestricted" to the material. But how can we judge this to be the case if the only being that we know is material being? While it is true that ens potentially, or if you like, virtually contains whatever is or can be known, our direct knowledge of it based on the senses tells us only about but the material and sensible things directly experienced by us.
Thus the judgment of separation of "being" from the "kinds" of being, as Wippel describes it in the foregoing summation, can be made only on the basis of our sense experience of real material beings which all in common have being but only a being restricted to materiality. How can we make the further step of extending the term "being" in that limited sense to immaterial beings by an analogical reasoning from effect to cause and thus establish that the object of Meta-Science exists, which is the first principle of all properly meta-scientific truth? In all his discussions of the existence of immaterial beings Aquinas insists that they are known to be included in ens commune only by a demonstrations from their material effects. Once their existence has been demonstrated a posteriori as the cause of material effects, it then becomes evident that the term "Being" can be extended without restriction to include whatever is common to both material and immaterial beings in a single judgment that Being as Being (in that extended sense) truly is-that it has esse. In this way, as Aquinas explicitly states in the texts I have cited, the subject of Meta-Science is validated, while it is not validated by the reconstruction that Wippel on the basis of a "few remarks" conjectures to be Aquinas' way. Thus the negative judgment of separation on which this allegedly superior way depends is evidently true only if its terms have first been established by natural science as real and not merely nominal.
For that reason, however, the subject of Meta-Science must indeed be "unrestricted" with regard to any kind of real being. It is insufficient however, merely assert that it is "unrestricted" without further validly judging that immaterial being as well as material being does it fact exist. It is in this precise sense that the term "separation" is needed to establish the object of Meta-Science. We can validly judge that the universal essence of changeable beings can be abstracted from their concrete condition of existence without losing their existence. And we can judge that mathematical beings can be abstracted from the other properties of really existing changeable quantified beings without losing their existence. But how can we judge-but without abstraction-that the object of Meta-Science includes both material and immaterial beings without losing its status as the actus essendi. Without that status it would, contrary to Wippel's claim, be reduced to mere possibility, a figment of the mind, as modern materialists claim that it is.
Thus, as with Dewan's remarks, I find nothing in Wipple's careful exposition of the Existentialist thesis, or in that of others of this school that answers that inescapable question. I grant with them that the object of metaphysics (Meta-Science) is known only by a judgment of separation, but for that judgment to be valid, somehow it must first be known that immaterial substances really exist. Wipple says, 
One judges that being, in order to be realized as such, need not be material, or changing, or quantified, or living, or for that matter spiritual. Hence one establishes the negatively or neutrally immaterial character of being, and prepares to focus on being as such or as being rather than on being as restricted to this or that given kind.
One may indeed make this judgment, but what validates it? Wipple in his lengthy chapter on "The Discovery of the Object of Metaphysics" casts no further light on this inescapable question. It is true, as he says, that the intelligibility of two material beings known to us to have have esse is not the same as the intelligibilities of their different essences. This, however, does not validate the judgment that this esse also includes the totally different esse of immaterial things, who existence we know only by a demonstration through their material effects. Therefore, as John Knasas also notes,  Wippel's argument from separatio leaves us completely in the dark.
Therefore Joseph Owens took another Existential approach to our question, Joseph Owens,  Owens was an expert on Aristotle's Metaphysics, and his solution to our question is stoutly defended and developed by John Knasas in his work cited above. Knasas for his own part maintains  that the arguments for a First Immaterial Cause in Aristotle's Physics, Book VIII and an immaterial human soul in De Anima III, are (at least as Aquinas' reads them) already meta-scientific arguments. Owens and Knasas cannot accept as adequate the position of Wippel, Sweeny, etc. nor the Aristotelian approach because, as Knasas puts it, 
Unlike separatio Thomists Owens makes no problematic claim that intelligibilities able to be apart from matter can be derived simply from the material. Unlike some Thomistic natural philosophers, he likewise makes no doubtful claims that matter/ form principles succeed in demonstrating immaterial realties. Finally, unlike Transcendental Thomists, Owens is under no pressure to take an apriori route to the immaterial with all of its tragic Kantian consequences. Owens is content to allow the judgmental grasp of esse in sensible things to specify the entry into metpahysics.
Therefore Owens and Knasas, though they also hold that the object of a Meta-Science is known by a judgment of separation that frees it from all immateriality, they deny that this judgment is necessary to begin that science. For them all that is required in establish the validity of a Meta-Science independent of natural science is to recognize that the material beings that we directly know from sense experience are beings that have the act of existence (habens esse). Therefore the demonstration of the existence of immaterial beings can be left as a task for Meta-Science to perform in the due course of its argumentation.
One would like to know, just as one would for Wipple, how Owens shows that his project is Thomistic or feasible, yet Knasas admits  that, although Owens has written extensively on this object, "As far as I know, Owens offers no such direct textual proof for his position."  Consequently, Knasas seeks to provide such a proof. He begins by referring to Aquinas' description in the Summa Theologiae I, q. 44, a. 2 c. of the three historical steps by which the object of a Meta-Science was historically established.  Knasas interprets these three steps not as degrees of immateriality but of "increasing profundity," in understanding the intelligibility of things as having esse. He understands these deepening insights to have been: (1) the materialism of the pre-Socratics; (2) the approach to Meta-Science through natural science of Plato and Aristotle; (3) the approach through habens esse that he accredits to Aquinas and which is that of Owens.
This interpretation is highly questionable, since the mention of Plato and Aristotle at stage (2) does not say that Aristotle (nor Plato) got no deeper in their thinking than that stage. In seems to me that Aquinas mentions them there only to indicate that as Greek thought moved from the first to the second stage a division arose between Plato's theory of Ideas and Aristotle's theory of the celestial spheres. Aquinas certainly cannot be saying that Aristotle got no further, since he knows perfectly well that Aristotle held that celestial spheres are moved by immaterial intelligences and hence arrive at immaterial being. Moreover, Aquinas does not claim the third stage as his own discovery but simply speaks of "Some who understood."
Though Knasas thinks that this text "catches Aquinas in presenting metaphysics simply in terms of habens esse," yet he raises the question whether knowing that material things have esse guarantees that this same esse can be considered without materiality, as it must be for a Meta-Science to be a science other than natural science. He has to answer this difficulty since he has himself raised it as an objection to the position of Wippel and others who share his views. Knasas resorts to the text so much favored by the Wippel on the "judgment of separation." Knasas understands this, however, to mean that the first operation of intelligence attains the essence of material being, but the second operation, namely, judgment attains its existence. He then cites texts of Aquinas to show that in every science when a judgment has been made that separates a universal essence from what is accidental to it, the intelligence by a reflex act then judges that this essence exists concretely together with those accidents, yet is utterly different than they are.
Therefore Knasas asks if it similarly possible for the esse of material things that differ in essence to be judged to be common to them yet free of their common materiality. He quotes Owen as showing that not only real material things have esse. Objects that have only mental existence also have esse, though a cognitional not a real esse. Thus he argues that it is possible to arrive at a judgment that the esse that a material object has in real existence can be considered as common to that same object as it exists intentionally and immaterially in the knower. Therefore esse so understood is neutral to materiality and immateriality and can serve as the object of Meta-Science. He grants that this is not ens commune as this is understood by most Thomists to be the object of Meta-Science, since that is an concept positively including all types of being, not neutral to them. Yet Owens and Knasas are content to leave the task of developing the understanding of ens commune to Meta-Science itself after it has established the existence of immaterial substances..
This solution like the other solutions of the Existential Thomists, in spite of Knasas valiant efforts to defend it, is wholly unsatisfactory even to other Existentials. Thus Wippel says of Owens' view, 
This approach fails to do justice to Thomas's understanding of the subject of a science, knowledge of which is required for one to begin the science. It also contradicts a principle Thomas accepts from Aristotle to the effect that no science can establish the existence of its own subject.
Furthermore, Owens' approach, even with Knasas' attempts to strengthen it, neglects a fundamental point that applies also to the approach of Wippel and others. Esse and essence are correlative causes, related as form to matter, and act to potency, hence though they are really distinct, one cannot be separated or known apart from the other. To say that "something has esse" means nothing unless we understand it in relation to the essence of that which has this "esse." It is untenable to suppose, as does Wippel, that what material beings of different kind have in common is simply a neutral esse. It has to be at least some generic essence that is correlative to and limits that esse. The broadest genus that we can judge from direct experience to have esse is ens mobile that is restricted to matter and motion. But though Knasas recognizes this error of Wippel, he makes a similar error when he asserts that for the material things that are the only ones we known directly to "have esse" is sufficient grounds for beginning a Meta-Science as a science distinct from natural science. The esse that material things have is the ultimate act and perfection of material things and as such its study falls within the scope of natural science and leaves nothing over as the object for an independent Meta-Science.
Thus what is common to all these conflicting Existential arguments is the assumption that any consideration of esse must be meta-scientific. In fact, as shown in Chapter III, every real science must first answer Question 1 about its subject , "Does it exist?" before it can proceed to the other questions about it. Hence science deals primarily with the intelligibility of the acts of its object and considers its potential aspects only in relation to its acts, first of all its actus essendi, or esse. Yet Owen says  that while Aquinas holds that being is accidental to an essence,
Can this interpretationâ€¦be called in any sense genuine Aristotelianism? At least there is no hint in the text of Aristotle that being per accidens and being as the true express basically but one way of being. Nor is there any notion in the Stagirites' [Aristotle's] doctrine that a further actuality is required for all forms, substantial as well as accidental. Still less is there any teaching in Aristotle that the being that answers the question an est is accidental to a thing. Rather, it is the general aspect of being that necessarily accompanies every definable thing. The definition gives the answer to the question quid est but you cannot know the quid est without thereby knowing the an est. If a thing can be defined it is by that very fact known as a being in the sense corresponding to the an est for Aristotleâ€¦.The definition would not be immediately known, but only mediately as the result of a reasoning process. So where the defining elements are not immediately known as such, the being that corresponds to the an est has to be known as such, the being that corresponds to the an est has to be known before the answer to the quid est can be attained (Apo.[Post. An.], II 8, 93116-b3). In no case, then can the quid est be known before the an est. For Aristotle, consequently, the an est does not signify any accidental or contingent existence. For St. Thomas, on the other hand, it denotes an accidental predicate. For Aristotle, the answer to the question quid est necessarily includes the answer to the question an estâ€¦For St. Thomas, on the contrary, the an est is asking precisely "Does the thing exist?" The being that answers such a question is accordingly an accidental predicate, whether it is the existence actually exercised by the thing in reality or whether it is the composition by the intellect in forming a proposition. That then is the first sense of being for St. Thomas. It is being in the sense of actually exercised existence. As such it is described as accidental to the thing.
Again this seems an apologetic attempt to find Aquinas superior to Aristotle. Aquinas may be somewhat more explicit than Aristotle on this point, but certainly they are in agreement that material things as such do not exist necessarily, since some material things at least come into existence and cease to exist. Hence for Aristotle, just as for Aquinas, existence is accidental to their essence and any proposition that asserted otherwise would be false. For Aristotle, just as for Aquinas, "the an est is asking precisely 'Does the thing exist?' since this must be affirmed by a judgment (second operation of the intelligence) before it can be defined.
Aquinas would agree that "The definition would not be immediately known, but only mediately" by analyzing and perhaps further observing the confused understanding of the thing known to exist, not, as Owens says, " as the result of a reasoning process." For example nothing can be known about a kangaroo until we observe a specimen and know that it exists as some kind of an animal, or at least a material object. To classify it specifically, however, is not done by reasoning (that is, demonstration) but by observation and classification.  When Aristotle requires that we affirm the an est before we can affirm the quid est he is requiring, just as Aquinas does, that this is necessary for the latter proposition to be true, either as an accidental predicate in the case of what does not exist necessarily or an essential predicate in the case of what exists necessarily, if there are such things.
Existential Thomism, as are most of the other types of Thomism, each in their own way, are suspicious of Aristotelian Thomism because they fear it imperils the certitude of a Meta-Science. They think that by making the foundational part of natural science the condition for a valid Meta-Science they are grounding it in a modern science that yields only probabilities and today is liable to post-modern deconstruction. They fail to see that the Aristotelian position does not expect from natural science to do more than to prove the existence of some causes that are not material. It leaves to Meta-Science the positive discussion of the nature of these causes. Moreover the proofs that natural science provides of immaterial existents are entirely independent of any of the details of natural science that are subject to revision because they are only probable. These proofs rests only (1) on the foundational part of natural science that is an analysis of our direct sense knowledge prior to the use of artificial observation or experimentation, and (2) on the argument that our human intelligence as it is presupposed to all science cannot be reduced to a merely material process.
 For a recent defense of this interpretation of Aquinas see John Haldane, John, "Thomism and the Future of Catholic Philosophy", 1998, Blackfriars Aquinas Lecture 1998, Internet http:/www.holycross.edu/
 This controversy is vigorously explored by John Knasas in his The Preface to Thomistic Metaphysics: A Contribution to the Neo-Thomist Debate on the Start of Metaphysics, especially as regards the views of Étienne Gilson, Jacques Maritain, John F. Wippel, and Joseph Owens whose position Knasas prefers. His extensive references make detailed bibliography unnecessary here.
Ibid. p. 551 f. Dewan say of the natural science approach to metaphysics as presented by James A. Weisheipl, "Thomas nowhere presents us with such a view of the formation of meta-scientific concepts: he everywhere treats the metaphysicals as a domain unto themselves, even though they are objects first encountered by us in sensible reality."
 Expositio super librum Boethii De Trinitate, ed. Bruno Decker,. Questions 5 and 6 are translated by Armand Mauer as The Division and Methods of the Sciences, Chapter 2, qq. 5 and 6, a.1. It was composed about 1257-1259 a little before the Summa Contra Gentiles and is contemporary with the disputed questions De Veritate generally considered to exhibit St. Thomas' mature epistemology. On the dating, see James A. Weisheipl, O.P., Friar Thomas D'Aquino. pp. 136f., 381f.; and Jean-Pierre Torrell, O.P., Saint Thomas Aquinas, op. cit. p. 345. Note that the contrast between the via inventionis by which principles are discovered and the via resolutionis by which they are applied in demonstration is not identical with that between the via resolutionis that analyzes a whole into its parts and. the via compositionis that again synthesizes these parts.
 The text of the Latin Avicenna (Venice 1552) says " post scientias naturales et disciplinas", i.e., "the natural and logical disciplines."
 In VI Meta, lect 1, n. 1170; also III, lect. 4, n. 398 and XI, lect 7, n. 2267. On this Dewan comments, "Aristotle there in fact says nothing about discoveries made by natural scienceâ€¦he saying that physics would be metaphysics if there were no separate entity. It is not said that physics discovers the existence of a separate entity. What certainly could be said is that, until they discover the existence of separate entity, the thinkers who do it, though they are metaphysicians, might not be able to distinguish themselves from physicists" (p. 553). He also remarks, "A thinker who does not draw the erroneous conclusion that all beings are bodies might well recognize that he was doing something different from the physicists even before he has succeeded in concluding to existence of separate entity." (p. 554, note 11).
 Dewan says, "If we find, in the treatments pertaining to physical science, some approach from the viewpoint of being, this will be, not properly physical scienceâ€¦, but a case of the physicists taking on the role of the metaphysician. Along these lines, Thomas tells us that the geometer proves his own principles by taking on the role of the metaphysician" (p. 557; in note 18). He supports this by quoting Aquinas, "For no science proves its own principles...He [Aristotle] says 'according as it is geometry' since it happens in some science that the principles of that science are proved in so much as that science assumes what is proper to another science, as geometry proves its own principles according as it assumes the form of , i.e., metaphysics." But a Meta-Science (if it has been shown to be valid) demonstrates the principles of the particular sciences only by deciding whether they pertain to all Being (ens commune), not only the subject of some special science. We teach geometry to children for whom, Aquinas says In Eth. VI, lect. 7, that metaphysics may not be taught. Dewan also quotes Aquinas In Met. IV, lect 1, on Aristotle c. 1 (1003a28-32) that early philosophers were seeking the highest causes and suggests that these Pre-Socratics, although they did not recognize the existence of immaterial things, were already metaphyisicians not natural scientists." But did they think these highest causes were immaterial?
 Dewan's states his position most precisely the second part of his article: "Thomas on the Formation of the Educated Mind" where he quotes the beautiful text In Eth. VI, lect. 5, n. 1181 that shows why metaphysics is the architectonic science (the very point to which the present book is dedicated) and says, "As that one is wise in some art is most sure in that act, so the science that is wisdom in most absolute sense is the most certain among all the sciences, in that it attains to the first principles of [all] beings which in themselves are most knowable, although some of them, namely immaterial [beings] are less known quoad nos. But the most universal principles are also most known quoad nos, as they are what pertains to Being as Being, whose cognition pertains to wisdom, as is said in Metaphysics IV, 6-8, In Met. Lect 7, nn.700-719. On this Dewan says (p.558), "Though some of these principles are less known to us than other things, nevertheless this claim is well founded, inasmuch as the most universal principles, pertaining to being as being, are both best known in themselves and best known to us [my italics] And these pertain to metaphysics. Obviously, if the first principles, as first known, were at first limited to corporeal being as corporeal, they would not be known as they pertain to metaphysics. Thomas sees the principles, precisely as known first of all and to all, as having the properly metaphysical character. This does not make the beginner a finished metaphysician, but it does mean that the principles of metaphysics are precisely those very first-known principles, not some newly constructed conception of being resulting from the study of physics. If we did not start with metaphysical principles, no particular science would ever provide them." On the contrary, I understand Aquinas as meaning that certain first principles such as that of Non-Contradiction and of Causality are first and best known to us in natural science in a restricted and hypothetical form as true for our actual universe. In their universal and necessary form, however, they are known meta-scientifically as applying to all Being material and immaterial.
 Ibid., p.558, note 20.
 In Met., IV, lect.5, n. 593 on Aristotle IV, 3, 1005a 31- b 2 and commented by John T. Wippel, The Metaphysical Thought of St. Thomas Aquinas From Finite Being to Uncreated Being (, pp. 55-57. For a review of this work see Emmanuel T