This entry raises the question whether Husserl’s theory of intentionality supports the sort of realism Thomists embrace. I argue that it doesn’t.

My Serbian correspondent Milosz sent me a reference to an article in Commonweal in which we read:

What attracted these Catholics to Husserl was his theory of intentionality—the notion that human consciousness is always consciousness “of” something. This appealed to Catholics because it appeared to open a way beyond the idealism of modern philosophy since Kant, which had threatened to undermine the possibility that human beings could possess an objective knowledge of realities outside the mind, including God.

Husserl’s phenomenology seemed to offer a solution to this problem. His promise to return “to the things themselves” sounded to many Catholics like a vindication of medieval scholasticism, which stressed that human beings have the capacity to objectively know reality independent of the mind. This led some Catholics to dub phenomenology a “new scholasticism.” By pointing “beyond” modern philosophy, they hoped that phenomenology could also serve as a path “back” to medieval thought, so that one might begin from the perspective of modern philosophy and end up somewhere closer to Thomas Aquinas. Husserl’s phenomenology thus opened up the possibility that modern, secular philosophy could be converted to Catholicism.

The Commonweal article is annoyingly superficial, and the last sentence quoted is just silly. Do I need to explain why? At the very most, Husserl’s doctrine of intentionality prior to the publication in 1913 of Ideas I could be interpreted as supportive of realism, and was so interpreted by many of his early acolytes, among them, the members of the Göttingen and Munich circles.    And so in some very vague sense, Husserlian intentionality could be taken as pointing back, via Franz Brentano, to medieval thought and to Thomas Aquinas in particular, assuming one doesn’t know much about Thomas or Husserl. But the claim that “Husserl’s phenomenology thus opened up the possibility that modern, secular philosophy could be converted to Catholicism” is risible.

Undiluted Roman Catholicism consists of extremely specific theological doctrines. No one could reasonably hold that a realistically  interpreted Husserl could soften secular philosophers up for Trinity, Incarnation, Virgin Birth, Transubstantiation, Papal Infallibility, etc.  (I will note in passing that it was the promulgation of the Infallibility doctrine that triggered Brentano’s leaving of the priesthood.) The most that could be said is that the (merely apparent) realism of the early Husserl was welcomed by Catholic thinkers. In any case, Husserl was not a realist, but a transcendental idealist as I will argue below.

But now let’s  get down to brass tacks with a little help from Peter Geach. I will first sketch the intentionality doctrine of Thomas. It will then become apparent, if you know your Husserl, that there is nothing like the Thomistic doctrine in Husserl. In the second main section I will explain how Husserl’s theory differs and how  it leads him to transcendental idealism.

A theory of intentionality ought to explain how the objective reference or object-directedness of our thoughts and perceptions is possible. How do our thoughts and perceptions reach things in reality ‘outside’ the mind? Suppose I am thinking about a cat, a particular cat of my acquaintance who I have named ‘Max Black.’ How are we to understand the relation between  my mental act of thinking, which is a transient datable event in my mental life, and its object, the cat I am thinking of? What makes my thinking of Max a thinking of Max?  Or perhaps Max is in front of me and I am not merely thinking about him but seeing him.  What makes my seeing a seeing of him? What makes these mental acts, whether of sense or intellect, take an object, and not just any object, but the very object they do take?  Please note that, while I have set up the problem as one concerning the relation of intentionality, it is not obvious that intentionality is a relation sensu stricto as we will see in a moment.

1. Intentionality in Thomas Aquinas

Here is what Peter Geach has to say, glossing Aquinas:

What makes a sensation or thought of an X to be of an X is that it is an individual occurrence of that very form or nature which occurs in X — it is thus that our mind ‘reaches right up to the reality’; what makes it to be a sensation or thought of an X rather than an actual X or an actual X-ness is that X-ness here occurs in the special way called esse intentionale and not in the ‘ordinary’ way called esse naturale. This solution resolves the difficulty. It shows how being of an X is not a relation in which the thought or sensation stands, but is simply what the thought or sensation is . . . .(Three Philosophers, Cornell UP, 1961, p. 95)

But what the devil does that mean? Allow me to explain.

The main point here is that of-ness or aboutness is not a relation between a mental act and its object. Thus intentionality is not a relation that relates my occurrent thinking of Max and Max. My thinking of Max just is the immaterial occurrence in my mind of the very same form or nature — felinity — which occurs physically and thus materially in Max. One and the same form occurs immaterially in my mind and materially in Max. The form itself is as it were ‘amphibious’ as between these two different modes of realization.

Aquinas, following Aristotle, views a concrete spatiotemporal particular such as Max as a hylomorphic compound, a compound of (substantial) form and (signate) matter. Old Max himself, fleas and all, is of course not in my mind, let alone in my head. It is his form alone that is in my mind.  ‘In my mind,’ of course,  is not to be taken spatially. If felinity informs my mind, however, why isn’t my mind a cat?

Here is where the distinction between esse intentionale and esse naturale comes in. One and the same form — felinity — exists in two different ways or modes. The form’s mode of being in my mind is esse intentionale while its mode of being in Max is esse naturale. You will note that the Thomistic doctrine of intentionality presupposes what I call the MOB-doctrine, namely, the theory that there are modes of being. Said doctrine is hardly obvious and is widely denied by distinguished contemporaries. I myself am open to the MOB-doctrine.

Because my thinking of Max just is the intentional occurrence in my mind of the same form or nature that occurs naturally in Max, there is no problem about how my thought reaches Max. There is no gap between mind and world.  One could call the Thomistic theory an identity theory of intentionality, or better, an ‘isomorphic’ theory.  One and the same form occurs in the mind and in the thing but in two different ways: with esse intentionale in the mind but with esse reale/naturale in the thing.  This isomorphism insures that the knower is not enclosed within the circle of his ideas and cut off from the world. It puts paid to the ‘gap problem’  that bedevils post-Cartesian philosophy. For Thomas, there is  a metaphysically antecedent community of nature between mind and world that underwrites the latter’s intelligibility to the former. Extramental beings are knowable by us because of this antecedent community of nature.

This view can be traced back to  Aristotle’s De Anima 431b20: “The soul (psyche, anima) is in a certain sense all things . . .” and a little before that, at 431b15 we read, “the mind when actively thinking is identical to its objects.” (emphasis added) No gap, no bridge, identity!

In sum, the sameness of form explains how the mind contacts reality outside the mind; the difference in modes of being or existence explains why the knower is not the known.  Knower and known are identical in respect of the common nature or form; knower and known are different in respect of how the common form exists in the knower and in the known. The common nature, as common, is neither immaterial nor immaterial, neither intentionally existent nor really existent.

That in a nutshell is the Thomist theory of intentionality. If you can see your way clear to accepting it as the only adequate account of intentionality, then it provides a bonus by supplying a reason for the celebrated real distinction (distinctio realis) of essence and existence. For the account requires that there be two distinct modes of esse, an immaterial mode, esse intentionale, and a material mode, esse naturale. Now if a form F-ness can exist in two different modes, then it cannot be identical to either and must be really distinct from both. (Cf. Peter Geach, “Form and Existence” in God and the Soul, Thoemmes Press 1994, pp. 62-64, orig. publ. 1969)

I have some questions about the Thomist theory, but I won’t raise them here because my present purpose is not to evaluate the Thomist theory but merely to contrast it with the theory of HusserI.

2. Intentionality in Edmund Husserl

We must now ask how Husserl’s approach to intentionality and thus to the possibility of knowledge differs from the above.  I say it does differ and that Husserl’s phenomenology gives no aid or  comfort to Thomist realism.  This is a large and controversial topic and I cannot say much about it in one weblog entry. But I must say something. I am not concerned at present with the tenability of either position. My sole present concern is to show that (i) Husserl is a transcendental idealist, and that therefore (ii)  Husserl’s position is incompatible with Thomist realism.

The Natural Attitude

The realism of Thomas was developed and is maintained within what Husserl calls the natural attitude (die natürliche Einstellung).  In the natural attitude the world we experience, live in, and act upon is naively taken as unquestionably given.  It is uncritically accepted as the ultimate backdrop of all our concerns, practical and theoretical. Within the world so taken there are knowers and things known. It also includes all intentional (object-directed) mental states, whether sensible or intellectual, of humans and animals. They too are taken to occur in the world of the natural attitude.  My seeing the cat or the mat on which he sits  is then explained under the presupposition that there really are,  extra-mentally, knowing beings and known beings.  A knower is a psychophysical complex, a minded organism.  Its mental or psychic states are naively taken as states or processes within the same spatiotemporal world in which the knowers’ bodily states occur.  This is all uncritically accepted and not put into question from within the natural attitude.

The natural attitude is not a philosophical theory, but is  prior to any philosophical theory one might adopt.  It is the pre-theoretical basis from which philosophical theories arise. So one must not conflate the natural attitude with  the philosophical theory of metaphysical naturalism, according to which  reality is exhausted by the spacetime system and its contents.

And while one needn’t philosophize within the natural attitude, and most don’t, one can.  One who philosophizes within the natural attitude may ask how objective knowledge is possible and may also ask about the relation in a knower between mental/psychic states  and physical states. Let’s briefly consider some natural-attitude solutions to the second problem, the mind-body problem.

If our natural-attitude philosopher is an Aristotelian he will hold that a knower is a hylomorphic compound in which anima forma corporis, the soul or psyche is the (substantial) form of the body.  The same goes for the Thomist, mutatis mutandis. If our natural-attitude philosopher is a hard-core materialist/physicalist, however, he will say that mental states are just states of the brain.  If our natural-attitude philosopher is a Cartesian substance dualist, he will reject all three of the foregoing positions and tell us that the soul/psyche/mind is an immaterial primary substance (and thus not a  form or state) really distinct from bodily primary substances. (There are of course other positions in the philosophy of mind such as epiphenomenalism, emergentism, supervenientism, panpsychism, functionalism, occasionalism, parallelism, and so on, all of them developed within the natural attitude.)

The four positions just sketched are all realist in the sense that the things the mind knows are taken to exist independently of the minds that know them.  On realism, the being of the things known is not reducible to their being-known, let alone their being thought-of.  But there is nothing to stop a natural-attitude philosopher from being an idealist who holds, like Berkeley, that esse est percipi, that to be = to be perceived.  On an idealism like this, which Husserl calls ‘psychological’ to distinguish it from his transcendental idealism,  the things known do not exist independently of knowers.

The main point, however, is that all of this theorizing, whether realist or idealist, is being done within the natural attitude.  So just as one must not confuse the natural attitude with any version of metaphysical naturalism, one must also not confuse it with any pre-Husserlian version of realism or idealism. Within the natural attitude, mundane idealists oppose mundane realists; Husserl’s idealism, however, is, or is supposed to be, transcendental or pre-mundane.   We will have to come back to this later.

Another point that needs to be made before proceeding  is that, within the natural attitude, one can perform an epoché or suspension of belief in the manner of such  Pyrrhonian skeptics of late antiquity as Sextus Empiricus.  There is such a thing as a natural-attitude epoché.  Suppose you tell me that Thomas Merton was assassinated by the CIA. There are three main attitudes I can take up with respect to this proposition: Accept, Reject, Suspend.  If I suspend judgment, I take no position with respect to the truth-value of the proposition you assert.  I merely entertain it without affirming it or denying it.  I put it ‘within brackets,’ if you will.  It is then, in Husserlian lingo, eingeklammert. But this Pyrrhonian bracketing is piecemeal and partial; it does not put the whole world of the natural attitude within brackets, as does Husserl’s, as we shall see.

The Pyrrhonian skeptic also advocates a sort of ‘reduction,’ a leading back, not from the thing taken naively as existing in itself to its appearing,  but from the propositional content affirmed as true or rejected as false, to the propositional content itself under bracketing of its truth-value.

Epoché and reduction in Husserl have a far more radical sense.

To understand Husserl, you must understand that his aim is to thematize what had been, before he came along, tacit and pre-thematic, namely the natural attitude and to show that it  presupposes something deeper,  transcendental subjectivity, a pre-mundane region of Being. He proposes to uncover this region of Being by way of a radicalization and purification of the Cartesian project of universal doubt. As he puts it in his late Paris Lectures, “The methodology of purified Cartesianism demands . . . the phenomenological epoché. This epoché eliminates as worldly facts from my field of judgment both the reality [Seinsgeltung] of the objective world in general and the sciences of the world.” (The Paris Lectures, Koestenbaum tr., 10) The word Koestenbaum translates ineptly as ‘eliminates’ is ausschalten. Its  relevant meanings in this context include switch off, disconnect, set aside, make no use of.  The idea is that if one aspires to be truly radical  in one’s philosophizing, and go to the root (radix) of the matter, one must set aside the reality or ontic validity [Seinsgeltung] of the world given in the natural attitude and make no use of any of its facts. In addition, radicality demands that we make no use of the positive sciences that investigate these facts.

But why perform the phenomenological epoché?

Before I can answer this question we need a quick Descartes review. Renatus Cartesius (1596-1650), troubled as he was  by the cacophony of conflicting beliefs, sought objective certainty.  He sought a fundamentum inconcussum, an unshakable foundation for his beliefs.  His method of search was by doubting everything that he could possibly doubt to see if there is anything that he could not doubt.  He sought the utterly indubitable. What he found was the cogito, the ‘I think,’ where thinking (cogitation, from L. cogitare, to think) ) is understood sensu lato to embrace every type of object-directed consciousness, whether perceptual, imaginative, memorial, judgmental, etc. He found that he could not doubt his thinkings (occurrent episodes or acts of thinking, cogitationes).  He could doubt particular objects of thinkings, particular cogitata, whether they exist in reality, and whether in reality they have the properties they appear to have, but he could not doubt the cogitationes directed upon these cogitata.  For example, if I see a tree, I can doubt whether there exists in reality, i.e., extra-mentally, a tree that I see, and I can doubt whether it really possesses the attributes (being in bloom, say) that it is seen to have.  What I cannot doubt is the existence of an object-directed visual experiencing as of  a tree in bloom.

There are, however, not just one but two items I cannot doubt. I cannot doubt the cogitatio, the occurrent episode of object-directed visual awareness, but I also cannot doubt what could be called the CONTENT of this awareness, what Husserl calls the noema of this noesis, namely the cogitatum qua cogitatum.  (Side note: Some philosophers in the analytic tradition assimilate Husserl’s noema to Frege’s Sinn (sense) which mediates linguistic reference.  If for Frege, linguistic reference is routed through sense (Sinn), for Husserl, thinking reference is routed through the noema. I do not endorse this interpretation, but cannot discuss it further here. It is known in the trade as the West Coast interpretation of the noema.)

The Ambiguity of ‘Object’

There is an ambiguity here that must be carefully noted, and it is relevant to the idealism question.   A cogitatum is an object of thought.  But ‘object’ is ambiguous. Do we mean the thing in reality that presumably exists and has properties whether or not anyone is aware of it or its properties? Or do we mean the thing precisely as it appears to a conscious being with only the properties it appears to have when it appears?  The latter alone is the cogitatum qua cogitatum, the object of thought just insofar as it is the accusative of an act of thinking, that is, just insofar as it is a correlate of a cogitatio, the noema of a noesis.  The cogitatum qua cogitatum is what I will call the PURE OBJECT.  It is distinct from the ego, from the ego’s cogitationes, and from the thing itself in mind-independent reality, should there be one.  We can then call the cogitatum simpliciter the THING.

‘Object,’ then, is ambiguous as between pure object and thing.  This parallels the ambiguity of ‘Every consciousness is a consciousness of something’ as between ‘Every consciousness is a consciousness of a pure object‘ and ‘Every consciousness is a consciousness of a thing.’ Suppose I am imagining a winged horse. Am I imagining something or nothing? Something, obviously, but something that does not exist.  In this case, the cogitatum, object of thought, is a pure object, not a thing (res).  A pure object is a Gegenstand inasmuch as it stands over against consciousness-of. A thing, as I am using the term, is not a Gegenstand, but a thing the being of which is not exhausted by its standing over against consciousness-of.  But I don’t call it a Ding-an-sich because, for Kant, the Ding-an-sich is unknowable whereas for Thomist realists the thing is knowable as it is in itself.  In passing, I will also note that we should beware of confusing Husserl’s transcendental idealism with Kant’s.   The main point of difference is that Husserl’s transcendental idealism requires the epoché whereas there is no epoché in Kant. I cannot pause to explain this now.

We must, therefore, distinguish the pure object from the thing. For example, when I look at Max, I see a cat, which is to say: I live through (er-leben) a conscious state that is object-directed, but is this actual experience (Erlebnis) of seeing directed to, and terminate at, a pure object? Or is directed to, and terminate at, an extra-mental thing? In the first case the directedness terminates at a pure object.  In the second case it goes through the pure object and terminates at the thing. In the second case the pure object is an epistemic intermediary, and not the thing known.

In the first case, my living through the experience as of seeing a cat does not guarantee the extra-mental existence of a cat that I see. For it may be — it is epistemically possible — that nothing in reality corresponds to the pure object or even to an ensemble of mutually coherent objects  that appear to successive acts. In the second case the experience latches onto the thing itself, grasping it in its mind-independent being.

Two Uses of ‘See’

The difference between the two cases is reflected linguistically in the difference between a phenomenological use of ‘see’ according to which subject S’s seeing of x is consistent with the nonexistence of x, and a ‘verb of success’ use according to which  S’s seeing of x entails the existence of x.  We find both uses in ordinary English. If I tell you that you are ‘seeing things’ I am telling you that what you are seeing isn’t really there, i.e., doesn’t exist. And in dreams we do see things that aren’t there.   This is the phenomenological use of ‘see.’ The verb of success use, however, is at home in the natural attitude.

Now back to our Descartes review. From Husserl’s point of view, Descartes, with his universal doubt is on the right track, but he doesn’t go far enough. He  is still partially stuck in the natural attitude, and fails to execute, or fully execute, the ‘transcendental turn.’

Descartes’ underlying schema is this:

D. Ego-cogito-cogitatum qua cogitatum-res.

Husserl’s underlying schema is similar but also importantly different in one respect:

H. Ego-cogito-cogitatum qua cogitatum-[res].

In (H) ‘res’ or ‘thing’ is bracketed, in (D) it is not. Let the thing be the paloverde tree in my backyard presently in glorious yellow bloom in the Sonoran spring. In the natural attitude we take the tree to exist in itself whether or not I or anyone make(s) it the object of an intentional (object-directed) act, whether a perceiving, a remembering, whatever.

But are we justified in taking the tree to exist in itself?

Granted, my seeing is an intrinsically object-directed state that purports to reveal a thing that exists and has the properties it is seen to possess whether or not I or anyone see it.  This purport is intrinsic to the conscious directedness. To put it paradoxically, the intentional state  intends the object as non-object. (I borrow this formulation from Wolfgang Cramer. It is paradoxical but non-contradictory. The paradox is rooted in the ambiguity of ‘object’ which I have already explained.)

To put it non-paradoxically, the intentional state intends a thing (purports to reveal a thing) the being of which exceeds its being a merely intentional object for a subject. Consciousness-of, by its very nature, purports or ‘wants’ to reach things transcendent of consciousness. This, I claim, is part of the phenomenology of the situation.   I am pretty sure that  Husserl would agree with this. Whether or not he agrees, the point I am making can be put in Husserlian jargon: what is intended is intended to be more than a mere noematic correlate of a noesis, and indeed more than an entire ensemble of mutually coherent noemata.  As it seems to me, what is intended in an intentional state is intended as existing an sich, in itself, and not merely for me or for us.  Consciousness-of, by an inner necessity, desires its own transcendence.  Every noesis is a nisus, a mental striving or perfective endeavor. These last two formulations are mine, not Husserl’s, but in line with his views.  But in the interests of strenge Wissenschaft (rigorous science), this lust for transcendence, which is endemic to the natural attitude, must be chastened and inhibited.

The purport to reveal a thing as it is in itself may also be expressed in terms Descartes borrows from the scholastics. Accordingly, what is intended in an intentional state is the thing in its formal reality (realitas formalis), its formal or trans-objective reality, and not merely in its  its objective reality (realitas objectiva) as an object for a subject.  ‘Objective reality’ refers to the reality the thing enjoys when its stands in relation to a conscious subject. ‘Formal reality’ refers to the reality that the thing has in itself whether or not it stands in relation to a conscious subject.

Of course, the purported reference of an intentional state beyond itself to a thing in reality may not pan out. Usually it does, but sometimes it doesn’t. It may be that  there exists in reality no  tree such as the one the directedness purports to reveal. In the natural attitude, we naturally go along with these purports in the vast majority of cases; we do not inhibit them as we do when we are doing phenomenology in the Husserlian style.

From this example we can begin to see what the phenomenological reduction or phenomenological epoché is all about. It is about inhibiting the natural tendency of mind to posit its objects as existing in themselves. The thing is bracketed as in schema (H): it is re-duced to its appearing. Ducere in Latin means to lead; a reduction, then is a leading back, a regression.

Before we get to the question of Husserl’s putative idealism, we need to ask and answer two questions: (Q1) why would he want to put the world of the natural attitude within brackets, and (Q2) why does he think that Descartes did not  go far enough?

Q1: Why the Need for the Phenomenological Reduction?

The short answer  is to avoid the epistemological circle. Husserl appreciates that one cannot answer the epistemological question of how objective knowledge of real beings is possible if one presupposes what one wants an account of, namely, objective knowledge of real beings. Let me explain.

Consider again my seeing of Max the cat. What makes my seeing a seeing of Max and thus a sensory knowing of Max? How do I know that he exists extra-mentally and has the properties extra-mentally that  I see him to have? A natural-attitude answer might be in  terms of causal actions of physical  things spatially external to my body that act upon my body’s  optical transducers (eyes),  which in turn convert photons into neural information which is then transmitted by electrochemical means to the  visual cortex in my brain, and voila! a cat appears.  Such an account is epistemologically worthless because circular: it presupposes that we have knowledge of both (i) the existence of mind-independent things and of (ii) the truth of the sciences of the natural attitude (physics, physiology, electrochemistry, etc.).  Husserl’s intention  is not to deny or doubt any of this.  His point is that no use may be made of it in epistemology.   A radical critique of knowledge cannot presuppose knowledge.

W. V. Quine would disagree. See his Epistemology Naturalized.

One objection to Quine from a SEP article has an Husserlian flavor:

(2) A second objection is that Quinean naturalism is viciously circular. Among the central tasks of epistemology, it’s said, is to establish that empirical knowledge is possible—that we may, for example, legitimately rely upon empirical science as a source of knowledge. However, Quine would have epistemologists make “free use” of the results of science from the start.

Q2: Husserl on Descartes’ Lack of Radicality

The reduction in Husserl is a two-step move: from the thing to its appearing to a subject, and then from the subject initially and naively taken to be psychological or psychophysical to the transcendental subject.  The reduction is thus a transcendental-phenomenological reduction.  Husserl’s beef with Descartes is that he doesn’t execute the second step.  In Cartesian Meditations, sec. 10, Husserl alleges that the Frenchman fails to make the transcendental turn (die transzendentale Wendung).  He stops short at a little tag-end of the world (ein kleines Endchen der Welt), from which he then argues to get back what he had earlier doubted, including the external world.

Despite his universal doubt, Cartesius remains within the world thinking he has found the sole unquestionable part of it. Although he achieves something very much like a phenomenological reduction, the Frenchman fails to inaugurate a transcendental-phenomenological reduction.  He reduces things to their appearances, but fails to properly identify that to which they appear, the transcendental ego. He misidentifies it as something within the world of things, not a material thing, but an immaterial thing. As I would put, Descartes reifies the transcendental ego. A thing is a thing whether material or immaterial.

The reification consists in the misconstrual of the transcendental ego as substantia cogitans, mens sive animus.  This gives rise to what Husserl calls the absurdity of transcendental realism.  Husserl’s thought seems to be that if one fully executes the transcendental turn one is left with no entity (res) in the world that can serve as the subject for whom there is a world. If everything in the world receives its Seinsgeltung (ontic validity) from the transcendental ego, then this ego cannot be a thinking thing or substance.  It cannot be either the empirical ego (the animated body that psychology and physiology studies) nor can it be a soul substance as it is for Thomas and his followers. It has to be the source of the ontic or existential validity (Seinsgeltung) of the objects that appear.

But this is perplexing. Just what is this transcendental ego if it is the purely subjective source of all Seinsgeltung?  Is it at all?  If it is or exists at all, then it is in the world, even if not in the physical world.  It is in the world, the totality of entities. But it can’t be inasmuch as the transcendental ego as the constitutive source of all ontic validity is pre-mundane.

The puzzle could be put like this. Either the constitutive source of all Seinsgeltung is pre-mundane or it is not. If the former, then it would appear to be nothing at all. If the latter, then it is not the constitutive source of all Seinsgeltung.

Conclusion

In a later post I may come back to the problem just posed, which concerns the tenability of Husserl’s final position, but for now, I believe I have said enough to scotch the notion that Husserl’s position supports Thomist realism.  Husserl’s phenomenology  is committed to transcendental idealism, according to which  beings do not exist in themselves but only for transcendental subjectivity.  Here is a characteristic passage:

Alles, was ich je als wahrhaft Seiendes einsehen kann, ist gar nichts anderes als ein intentionales Vorkommnis meines eigenen — des Erkennenden — Lebens . . . . (Erste Philosophie (1923/24), Zweiter Teil, Theorie der Phaenomenologischen Reduktion, Husserliana Band VIII, S. 184 f.)

Whatever I can recognize as a genuine being is nothing other than an intentional occurrence of my own — the knower’s — life . . . .

For Husserl, the very Being of beings is their Being for consciousness, their being constituted in and by consciousness.  Their Sein reduces to Seinsinn, and that Sinn points back to the transcendental ego from which all sense derives. So the Sinn is not Original Sinn, pun intended, but derivative Sinn. Therefore, on transcendental idealism, contingent beings have no need for a divine ground of their existence, their existence being adequately accounted for by transcendental subjectivity. And since they have no need of a divine ground, one cannot prove that they must have such a ground. Husserl’s phenomenology lends no support to Thomist realism such as we find in Gilson and Maritain.  It is indeed incompatible with it.

The Commonweal article under critique is here.