What are the criteria of being a Thomist?

John Knasas defines a Thomist as “a philosopher or theologian who believes that his (or her) seminal, or core, ideas agree with those of the thirteenth-century Dominican theologian St. Thomas Aquinas, as that philosopher or theologian reads the Thomistic texts.”Footnote ¹ In another text, John Knasas suggests that there are currently three or four main schools of Thomists: Aristotelian Thomists, Existential Thomists, and Transcendental Thomists (with the possible addition of Personalist or Lublin Thomists).Footnote ² To these four, then, we can also add Analytic Thomism; a phrase apparently first coined by John HaldaneFootnote ³, but seemingly dating back to what might be called ‘Wittgensteinian’ ThomismFootnote ⁴ which began with philosophers such as Elizabeth Anscombe and Peter Geach.Footnote ⁵ For Haldane, to be a Thomist one must follow ‘the set of broad doctrines and style of thought expressed in the works of St. Thomas Aquinas and of those who follow him’.Footnote ⁶

With such diversity of ways of being a Thomist it is inevitable that tensions arise about how far one can be both a Thomist and follow a particular school or method of contemporary philosophy. Knasas, for instance, intimates that being a Thomist excludes the possibility of also being “a Kantian, Hegelian, or Heideggerian”,Footnote ⁷ but even this is somewhat problematic given that many contemporary forms of Thomism are associated with reading Thomas through the system or methods of particular modern philosophers, e.g., the association of Transcendental Thomism with Kantianism. This tension then gives rise to what Fergus Kerr, citing Serge-Thomas Bonino, calls a ‘hermeneutic conflict’ in which the pivotal questions concerning the diversity of ways of being a Thomist becomes whether the interpretation is true of Thomas’ philosophy, or alternatively, whether some forms of Thomism are just completely misguided.Footnote ⁸ Implicit in this question of hermeneutic conflict is the claim that to be a Thomist properly speaking one must, in essence, get one's reading of Thomas right.

In the broadest sense, then, we might say that to be a Thomist is constituted by two things: holding that Thomas’ system of philosophy is closest to the truth or leads us to the truth,Footnote ⁹ and additionally, that if one is to attain the objective of philosophy; the truth, one must be genuinely faithful to Thomas’ philosophy, in particular Thomas’ pursuit of the truth of being.Footnote ¹⁰ If this is the case, then it follows that the test of integrating or synthesising contemporary approaches to philosophy with the philosophy of Thomas Aquinas entails two questions: whether it is possible to unpack the truth claims made by Thomas in further depth and complexity through that approach to philosophy, and further, whether it is possible to remain genuinely faithful to the integrity of Thomas’ philosophy at the same time.

Given these basic criteria this paper will attempt to ask about whether it is possible to be a ‘phenomenological Thomist’. The attempt will be made to test out whether phenomenology as a methodological approach to ontology can be used to unpack the claims made by Thomas about the meaning of being in greater depth and complexity. At the same time, the paper will also attempt to test out the possibility of whether it is possible to posit a phenomenological approach to the question of the meaning of being while also remaining genuinely faithful to the integrity of Thomas’ metaphysics.

Problems in testing the possibility of phenomenological Thomism

The first issue that we need to contend with in working out whether it is possible to be a phenomenological Thomist is the difference between being a phenomenologist, in the sense Heidegger proposes it, and being a Heideggerian, in the sense of following Heidegger's overarching way of thinking and his truth claims about being. The latter entails a whole raft of views, such as the claim that Metaphysics must be overcome or that the history of metaphysics is a ‘covering over’ of the question and meaning of being,Footnote ¹¹ that are inherently inimical to any claim to be a Thomist. This is the sense, I think, in which Knasas suggests that being a Thomist excludes the possibility of also being a Kantian or Hegelian or Heideggerian. It is clear at this point that it is impossible to be a Heideggerian-Thomist insofar as Heidegger's aim is to deconstruct the notion of being as it develops within the tradition of metaphysics and Thomas is clearly one of the greatest exponents of being in that very same tradition.

It seems then that we can add a further criterion of what it means to be a Thomist based upon the difference between engaging in a method of doing philosophy and the overarching view of what constitutes philosophy as a systematic and unified endeavour. For example, one can be an analytic Thomist through the synthesis of the analytic method of philosophy and the broadly speaking Thomistic view of what philosophy entails as a systematic pursuit of truths about reality. To be a Heideggerian-Thomist, on the other hand, would be to attempt to integrate two contradictory overarching systems of philosophy; two fundamentally opposing meta-philosophical positions on reality and the nature of philosophy itself. To be a Thomist, then, is to be committed in some sense to the overarching meta-philosophical, or metaphysical, system of Thomas Aquinas.

On the other hand, when Heidegger proposes his own version of phenomenology as the proper methodology for engaging in ontological investigations in such works as Being and Time and Basic Problems of Phenomenology it is possible to find a common agenda, a shared love of the truth and reality of being, that would hint at the possibility of a synthesis of phenomenology and Thomism. In this sense, to talk of the possibility of phenomenological Thomism is really to talk about using the ‘phenomenology-as-ontology’ methodology as a way of shedding light upon and unpacking in further depth and complexity the claims that Thomas makes about being. It follows, then, that the test of the possibility of being a phenomenological Thomist will rest on the question of whether phenomenology, as a method of doing philosophy, can be integrated with Thomist metaphysics and can shed further light on the Thomist notion of being.

Martin Heidegger's conception of Phenomenology as the methodology of ontology:

Phenomenology, as Heidegger posits it in Being and Time, is a way of philosophical investigation that looks to discover the truth of being within a formal relationship between entities ‘as manifest’ and being as ‘the ground’ of that manifestation.Footnote ¹² Being, Heidegger asserts, is the hidden ground of the way in which entities are intelligible or available to thinking through experience.Footnote ¹³ Phenomenology, as such, can be divided into two interrelated claims: a claim about the relationship between being and entities that is given in everyday experience, and additionally, a claim about how philosophy can legitimately move from the way entities are intelligible via experience to the meaning of being as the ground of that intelligibility.

The first claim hinges on an ontological principle posited by Heidegger in various forms in the early stages of Being and Time, namely: ‘that being is always the being of an entity’.Footnote ¹⁴ According to Heidegger if philosophy is to ask the question of the meaning of being (qua being) – the question of traditional first philosophy since Aristotle – then it needs to pay attention to this relation and stay within the question of the relation between entities, the being of entities, and being qua being. That there is a relation between the entity, the being of the entity, and the question of being qua being suggests a number of possible lines of investigation for phenomenology. The first is that relation signifies some kind of analogy or likeness between being (as ground), entities (as manifest), and being qua being,Footnote ¹⁵ and additionally, that there must also be some degree of difference between entity, being, and being qua being.Footnote ¹⁶

Phenomenology, in this sense, runs parallel to what might be called the path of Aristotelian induction as it operates in the first books of his Metaphysics, beginning with the way entities are manifest in human experience and then moving from there back into the question of the principles and causes of the entity.Footnote ¹⁷ Unlike many other interpreters of Aristotle, however, Heidegger is opposed to the tendency to view this process as one of abstraction.Footnote ¹⁸ Phenomenology will not begin with experience and then perform an ‘objectification’ or mental abstraction of universal and unifying causes and principles of the experienced entity.Footnote ¹⁹ Heidegger's view of first principles is much more in line with Kant's critical philosophy in that first principles are constituted as the necessary grounds underlying the manifestation of the entity.Footnote ²⁰

For philosophy to investigate being as such it must be able to traverse the ‘ontological difference’ between beings (as manifest) and being (as ground).Footnote ²¹ It is clear at this point that Heidegger rejects what is nowadays called ‘naive realism’ inasmuch as his approach to phenomenology does not assume a straightforward unity of thinking and reality, i.e., does not take for granted that being is self-evidently given in our experience of entities. At the same time Heidegger also clearly intends to reject the ‘subject-object’ divide endemic in enlightenment and post-enlightenment philosophy inasmuch as he asserts an intrinsic and necessary relation between entity and being which precludes giving primacy to the distinction between subjectivity and objectivity.Footnote ²² The key question that phenomenology begins with then is the indicative relation between the meaning of being (as ground) and entities (as manifest to us in an intelligible way). In one sense, this is precisely what Heidegger means by phenomenology – to ask about and to resolutely remain within the question of the structure of the intrinsic relation and ontological difference between entity and being.

If we follow Heidegger's claim that there is an intrinsic and indicative relationship between the intelligible manifestness of entities and being as the ground of that manifestness then the question arises as to what constitutes this relationship and how philosophy can traverse that relationship properly; how does the manifest entity indicate or point towards being as ground? Heidegger initially intimates that this traversal from entity to being is possible on the basis of ‘original and intuitive grasping and explication’.Footnote ²³ Unfortunately, the key to this traversal in Heidegger's account of phenomenology is not explicitly developed in any further depth, primarily because he secures the foundation for his own phenomenological endeavours in Dasein; the being-understanding of human beings. This is why, in Being and Time, Heidegger focuses on what he calls ‘fundamental ontology’ or the existential analytic of Dasein.Footnote ²⁴ In this case, we can traverse the ontological difference from entity to being precisely because the relation is interior to ourselves. This, of course, is not sufficient to constitute Heidegger's phenomenology as a way of doing philosophy or even first philosophy in the broadest sense (rather than philosophical anthropology) for it forces the reader or disciple of Heidegger to follow his path through Dasein and Dasein's sense of being back to the question of being qua being; a path that Heidegger himself arguably failed to traverse.

Prior to the publication of Being and Time Heidegger offered a series of lectures now published as The Phenomenology of Religious Life in which he talked about bridging the entity-being difference through ‘formal indication’.Footnote ²⁵ Unfortunately, his exposition of the meaning of formal indication was cut short by students who complained that the course had nothing to do with religion.Footnote ²⁶ What Heidegger did discuss, in brief, was that formal indication contained three intrinsically unified senses: ‘what’ is experienced (content), the ‘how’ of the experience (relation), and how the experience is ‘enacted’.Footnote ²⁷ These three senses of formal indication express, in the broadest sense, the way ‘intentionality’ is employed in phenomenology to analyse and unpack the capacity of the intellect to grasp being in its immediacy.Footnote ²⁸ Formal indication, as such, is the method of traversing from entity to being through a primal experience and engaging in an in-depth analysis of that primal experience in order to uncover the basic structures of the way being is indicated as ground in the intelligible manifestation of the entity.

Whether we follow Heidegger's path into Dasein's sense of being or whether we attempt to adapt the curtailed and incomplete notion of formal indication probably doesn't matter. Underlying both is a presupposed indicative relation between the entity and its being.Footnote ²⁹ In either case, if the ontological difference is to be traversed, and further, traversed in a way that allows philosophy to analyse and interpret being as such then it follows that there must be a real and truth enabling relation between the manifest entity and being as its ground. This indicative relation, for a phenomenologist, will be possible to uncover through an analysis of the ‘primordial’ or ‘pre-theorised’ experience of entities as manifest to human understanding. I would suggest, on this basis, that the real test of the possibility of phenomenological-Thomism is the question of whether in analysing and interpreting the basic infrastructure of the experience of entities and how they are manifest to us can serve as a basis for shedding further light on Thomas Aquinas’ conception of being.

It is reasonably clear, on the basis of the discussion above, that Heidegger's phenomenology can be used as a way of positing a form of ‘realism’ that does not naively rest upon notions of self-evidence and does not lead to abstract ‘objectivist’ (or subjectivist) notions of being. In fact, to engage in phenomenology as ontology provides the opportunity to analyse and interpret the fundamental infrastructure of what it means to be a realist through an exploration of the ‘given-ness’ of being in the entity manifest in everyday human experience.

The task of this article is to test the possibility of a ‘phenomeno-logical-Thomism’. The question that remains, then, is that of precisely how this possibility can be tested? Phenomenological-Thomism, if it is to add anything to the thought of Thomas Aquinas whatsoever, will investigate the relationship between the manifestation of the entity and being in such a way that the infrastructure of Thomist realism is disclosed and the meaning of being, as posited by Thomas, is analysed and unpacked in further depth. Phenomenology begins with the ‘showing-itself’ of entities in experience. Therefore, in what will follow the article will use a particular experience as a means to attempt these tasks.

A Phenomenological Interpretation of the experience of the being of entities:

One of the activities I enjoy the most in life is going for what we call a ‘bushwalk’; that is, walking through preferably remote and rugged terrain in one of Australia's extensive national parks. Given that this activity constitutes an experience of the kind the article needs, I will use it as the basic framework for the phenomenological interpretation to come. Imagine for a moment then that you are walking through the bush, or the woods, or forest, or whichever similar experience you are familiar with …

The first thing one notices when bushwalking, especially if you are not with other humans, is the intertwined but distinctly doubled nature of the experience; on the one hand there is the horizon or environment of the walking, and on the other there is the individual entities that we notice whilst walking. Both are important to a phenomenological interpretation of the experience of the being of entities but the individual entities are those things that give us our first access to the question of being. Given that this will be a phenomenological investigation we must first ask: how do individual entities show themselves to us in the experience? In asking this question, inasmuch as we are addressing the being of entities that are not humans, it will be important to focus on the way in which entities show themselves rather than the intentional structure of the experience.

What is it that draws our attention to individual entities? There is a sense, of course, in which the local environment and its dangers will dictate what it is that humans look for whilst bushwalking. In Australia, for instance, it is tantamount to suicide to not be on the lookout for snakes, so a great deal of focus in this environment will be on looking for things that might be snakes, e.g., sticks, lizards, bark, etc … Likewise, the point of bushwalking is more often than not for the aesthetic experience; the grandeur, the mystery, and wildness of land not touched by human homeliness. Excluding this kind of ‘looking out’ for particular things, there is nonetheless something about the individual things themselves that draw our attention.

The place to begin an explication of this showing itself is the immediate sense perception that draws our attention and the nature of what it is that shows itself. It is interesting to note that it always appears to be difference that shows itself in the first instance to our perception; a rock or flower that is a striking colour, a tree that is losing its bark leaving streaks of colour down its trunk, the movement of branches in the wind, or an unusual shape. The immediate showing itself of entities, then, involves some kind of self-differentiation from the surrounding environment, some kind of feature that stands out and calls for our attention as if to say “here I am, look at me”.

It is not merely difference, however, that calls our attention to the showing itself of an entity, for it is never simply a striking colour, or streaks on the trunk of a tree, unusual shapes, or even movement that draws our attention to entities. These are merely the signs which point towards the showing itself of entities. When bushwalking, we are also aware of the showing itself of most of the entities which immediately surround us and we will give at least token attention to all of those entities that are immediately available to us.

To engage in a phenomenological interpretation of the showing itself of an entity we need to go past the immediate sense perception, to dig deeper into the question of how an individual entity shows itself, and to ask the question of what it is for an entity to show itself in a universal sense. We can start with the claim that at the very base level an entity shows itself to us as a sheer existent; an entity is there, or is present, not simply for or in our perception, but is there as such for and in itself, and as itself.

So, what is existence as the bare showing itself of an entity? Formally, we could say that this bare showing itself is identity or individuality. It is also a differentiation; for individuality distinguishes from an environment or horizon. Formally, existence also signifies integrity – the unified whole of identity. These formal characteristics are all there in existence, but also only tell us about the ‘what’ of existence; what existence is inasmuch as it is intelligible to the human intellect. To engage merely with the formal concept of existence at this point is to jump ahead of ourselves and to perhaps miss something of importance. The question in the first instance is not ‘what’ existence is, but the ‘how’ of existence inasmuch as it is the way into understanding the ‘showing itself’ of an entity.

To exist is to be-there in such a way that one is both unique and common at the same time. An existent entity will always share with other entities common properties or characteristics. However, it is not the common properties or characteristics, in the first instance, that show themselves as the existent entity. When I bushwalk, I do not see a tree and mistake it for every other tree. Rather, when my attention is drawn to a tree it shows itself in the first instance as something standing out and as having some kind of immediate integrity. It is not even the individual tree's unique features; its attention grabbing movements, shape, or colours, that strikes me. It is the entity's individual existence that shows itself.

The next question, then, is how an entity shows itself in this way and what existence means here. How is it that an entity shows itself as an individual integral whole? The clue to answering this question lies in the nature of ‘existence’ as a showing itself – in fact – as the most immediate and basic ‘showing itself’ of an entity. If we can analyse and unpack existence as a ‘showing itself’ then we should be able to draw out the fundamental characteristics of the being of an entity in its immediacy.

Thomas Aquinas claims in his Commentary on the Sentences that ‘the word being (ens)Footnote ³⁰ is imposed from the very act of existing (esse) … ’Footnote ³¹ and similarly in the Summa Contra Gentiles, ‘(esse) is that by which substance is given the name of a being (ens).’Footnote ³² It is clear in both cases that for Thomas, our first access to being; even in circumstances where we do not really understand what being truly means, is grounded upon our experience of the esse of an entity. In the first statement, we find Thomas arguing that the concept of the being of entities is arrived at and necessarily grasped by the intellect through esse. In the other, we find Thomas arguing that our access to a substance is grounded upon esse. It follows, therefore, that what Thomas means by esse corresponds with our immediate experience of an entity as an act of existence and therein our first point of access to the meaning of being. The immediate act of existence, however, is only the point of entry into the question of the showing itself of the being of entities.

‘Showing itself’ or being-present is not a static presence. If anything, ‘showing itself’ is precisely the opposite and has the fundamental characteristic of act or activity. The tree with the peeling bark and the bright colours on the trunk beneath shows itself immediately as being-there inasmuch as it has an act in the most general sense. The peeling bark and the bright colours underneath are-there only inasmuch as they belong to the overall act of the tree. It is this bare self-giving ‘act’ that constitutes ‘showing itself’ in such a way that we can talk about or perceive the actuality of the tree – it is there only insofar as it has an act that shows itself as self-presenting in act. In this bare brute ‘act’ of existence each entity is individualised inasmuch as it is only there as an individual act and is no other act than its own.

Likewise, the peeling bark, the movement, the colours, the differences which call out for attention are the ‘showing itself’ of activity; the tree shows itself precisely in the way it has activities that call out for attention or present themselves as something to notice. Even with regard to those things which do not move themselves we still find, in the way they show themselves, activities which constitute their existence. For example, on my bushwalk the piece of quartz rock shows itself as an act that allows the activity of glittering in the light of the sun and bright whiteness that stands out. Whether an entity is animate or inanimate makes no real difference; all entities have at the very least delimiting activities or boundaries of what activities they may or may not undertake given their act of existence. Activities, as such, are all expressive of the individual act.

Thomas’ arguments about the nature of esse provides us with the means by which we can provide an analysis and interpretation of esse as individuating. For Thomas, unlike Aristotle, it is not merely matter that individuates although matter is a feature of the individuation of composite entities.Footnote ³³ Thomas writes, in ‘De ente et essentia’, that there are substances, powers, or entities composed of form and esse, but not matter.Footnote ³⁴ Given this, it follows that they are individualised on the basis of their esse.Footnote ³⁵ If this is true, it is also possible to argue that composite entities (physical entities) are individualised at least in part on the basis of their esse. To be manifest as an individual entity is to be present to and for others in act and through activity.Footnote ³⁶

We can unpack and explain the way in which esse individuates in further depth. The clue here is the way in which Thomas argues that in all created beings esse is finite, and thus, a limited act of existence.Footnote ³⁷ This then explains, in part, why it is that when I bushwalk I do not encounter one tree and mistake it for every other tree, for it is precisely the finitude or limited nature of the individual act that is manifest in the experience of the singular tree.

To have a limited act, however, can be taken in two ways: as a universal delimitation or in relation to activity. In one sense, limit or finitude signifies a universal existential boundary; that is, each entity is manifest in experience as an individual act that is limited inasmuch as it is not another act aside from itself. This limiting act does not necessarily disclose anything about itself in the first instance aside from the fact that it has a dynamic presence in the world that is existentially distinct from other acts.Footnote ³⁸ In another way, to be limited in act is to be manifest as spatio-temporal; to be there through the activities of change, movement, and dynamic potency. It is the fact that individual entities have certain activities, engage in particular actions, and are present as dynamic actualities that there is something in the experience towards which our attention can be drawn. The sheer individualised act of existence of the being of entities, therefore, is constituted by a dynamic self-presentation that is limited in its existential extension and a delimited potency for change or movement that announces itself as manifest through activity. However, although esse as limited and finite discloses the individuality of the entity as manifest, it does not yet explain the integrity of the act of existing.

What, then, gives an individual act its integrity; its unity as a whole act of existence? Certainly there must be an integrity to each entity qua act of existence, for integrity is the necessary ground (or principle) of the individualised act. To provide an answer to this question, however, would be to jump ahead of ourselves again inasmuch as answering this question involves a jump from ‘how’ an entity shows itself to ‘why’ the entity shows itself as such. This question, as the reader would be aware, is nothing other than the question of the primary meaning of being; in Aristotelian terms, the question of the primary sense of being amongst the several senses.

To discover the primary sense of being is to disclose the truth about being. Here, we are aided by Thomas’ argument to the effect that truth is grounded in esse; ‘since both quiddity and existence (esse) are present in a thing, truth is grounded on the thing's existence (esse) more so than upon its quiddity.’Footnote ³⁹ The question of truth, however, refers us back to the question of the integrity of the entity in its being and in turn to the ‘why’ of the entity rather than ‘how’ it shows itself as esse. Thus, even though esse is the ground of the possibility of truth and is the truth inasmuch as truth is in some sense independent of the intellect, to have the truth in full requires something in addition to the esse of the entity.Footnote ⁴⁰ For Thomas, to have the truth – as it was the case for Aristotle – is to understand the reason why the entity as it shows itself is an integrated unified whole. To get to this we must first be able to traverse the ontological difference between the manifestation of the entity (esse) and the being of the entity (ens).

In interpreting the meaning of existence as the ‘showing itself’ of entity through act and activity we are nowhere near able to answer this question as yet. Indeed, the act or activity of existence is not, and cannot be, the primary sense of being, but is merely the entrance point to asking the question in the right way. We can say with some certainty, however, that this phenomenological interpretation of the ‘act of existence’ indicates that the meaning of being must necessarily provide us with a ‘reason why’ entities are an integrated unified whole. In other words, being must at the very least signify the ‘reason why’ or ground of the integrated identity of individual acts of existence.

The showing itself of the horizon or local environment of the walking:

The phrase ‘esse commune’ is often thought by interpreters and scholars of Thomas to signify the general ‘nature of being’ of created beings.Footnote ⁴¹ As such, ‘esse commune’ is thought to be in some sense a correlate of ‘ens commune’; in which the latter signifies the formal concept of being in general (being qua being) while the former signifies the manner in which entities have their common participatory act of existence as created beings.Footnote ⁴² Insofar as ‘esse commune’ is interpreted this way it is for the most part constituted as the means by which Thomas differentiates between how the human intellect has access to knowledge of God; as self-subsistent ‘esse’ only knowable through the effects of God's acts via analogy,Footnote ⁴³ and the kind of existence all beings have insofar they are created. Moreover, some scholars of Thomas also suggest that the concept of esse commune is solely an intellectual abstraction which has no real meaning outside the esse of individual entities except for the fact that they are all created and every individual entity participates in an existence dependent upon their creator.

I would suggest, however, that the notion of ‘esse commune’ may have wider application and can aid in the task of accessing the meaning of the being of entities further than this interpretation would imply. Rather than presuppose that esse commune simply signifies a general notion of created being, I will return to the experience of bushwalking in order to ask what we might find out about the meaning of esse commune, and further, how the notion of esse commune might serve as a point of entry into the question of the meaning of being of entities.

If we return to our experience of walking in the bush (or equivalent) we find that there is still a second key feature of our experience yet to be interpreted phenomenologically, namely; the way in which our experience contains a horizon or local environment in which entities are manifest. What does the horizon or local environment of the bushwalk indicate about the meaning of being an entity?

When we walk along a track in the bush we are always aware of the local environment in which we walk. In this awareness of the local environment we are immediately aware of the presence of various entities and we are also aware of a unity or common context of the various individual entities. The horizon of a bushwalk, as such, includes the individual acts of entities, but is also more than the sum of those individual acts. The question of the horizon, it follows, is how it is that the horizon is ‘more’ than the sum without the horizon itself being an individual act. In a phenomenological sense the question can be framed in this way: what constitutes the ‘more’ of the horizon and how does this ‘more’ show itself as manifest in experience?

The first and most immediate manifestation of the ‘more’ of the horizon of the bushwalk is the way it appears to give itself through identity and difference. Individually existent acts are present as unique identities and it is the horizon, therein, that appears to provide the space in which these individual acts are differentiated. Difference, therefore, seems to be constitutive of the ‘more’ of the horizon. However, we need to be careful here about what we mean by difference, for if we dig a little deeper into our experience of how the horizon shows itself we find that the appearance of difference only points to something more fundamental.

If we pay close attention to the showing itself of the horizon we find that difference only appears inasmuch as the individual entities can be differentiated from one another on the basis of relation. For example, when on a bushwalk in the Australian Blue Mountains – my favourite being the National Pass walk in Wentworth Falls – the path at one point sits in the middle of a cliff. The horizon of the walk, here, is a sheer cliff face above and a sheer drop to the other side. Individual entities are differentiated from one another within the horizon only inasmuch as they are related to other entities; there are trees that have grown out of cracks and crevices in the cliff face, lizards (or snakes) lie on rocks in the warmth of the sunlight, water falls down canyons formed by the relations of water, wind, and sandstone. A fence runs along the edge of the drop. The experience of difference in the horizon of the walk, therefore, shows itself as a distinction grounded upon relation. If the ‘more’ of the horizon of experience shows itself as relation, then the phenomenological question remains as to what constitutes this relation? What are the basic characteristics of the relational showing itself of the horizon?

The first characteristic of this relational showing itself of the horizon is what we might call the ‘common act’ constitutive of the common unity of individual entities in relation to each other. When we carefully consider how it is that we find unity in the showing itself of the horizon we find nothing more or less than a unity of interaction; that is, individual entities become the horizon inasmuch as they have an active presence that is mutually determining and mutually affecting. Each individual entity is an act of existing, and yet at the same time, each individual act only shows itself and only engages in activities inasmuch as it is already in relation to, and therefore in a common unity with, other individual acts. In other words, to have an act or to engage in activities is always already to be in a relation with others. Thus, in the first instance, the common act signifies the way in which entities show themselves as an interaction which forms a unified horizon of existence.

In Thomas’ thought the meaning of this horizon as a common unity through act (esse commune) is posited through and within an integration or synthesis of the Neo-Platonic notion of participation with the Aristotelian prioritisation of the individual act (as ousia).Footnote ⁴⁴ Within Thomist scholarship, however, there is great debate as to which philosophical system; Aristotelianism or Neo-Platonism, serves as the hermeneutic key to interpreting the notion of esse commune.

Those of Aristotelian bent propose that the notion of esse commune is in effect synonymous with ens commune and refers to the intellectually abstracted notion of being that has no reality outside the intellect.Footnote ⁴⁵ Often, a passage from the Summa Contra Gentiles is cited in support of this proposition: ‘Much less, then, is esse commune itself something outside all existing things, save only for being in the intellect.”Footnote ⁴⁶ The problem, of course, with this reading is that the claim that esse commune is not an entity with being does not necessarily support the conclusion that it is merely an abstraction.

Other Thomist scholars more inclined to accept the reality (in some sense) of esse commune tend to cite a passage from Thomas’ In librum beati Dionysii De divinis nominibus expositio in which he treats esse commune as that which is common to all things, and further, that all created entities depend on esse commune.Footnote ⁴⁷ This dependency on esse commune is then thought to express the centrality of the neo-Platonic notion of participation in Thomas’ notion of existence inasmuch as each individual entity, qua being created, has its existence through participation in creation.Footnote ⁴⁸ On this reading, therefore, there is a real extra-intellectual dimension to esse commune – namely; that all finite entities exist in a common unity through and in participatory act.

Each of these tendencies in reading Thomas go further than it is possible here in that they have both already jumped from the showing itself of entities and their horizon into the question of the reason why of the horizon. That is, both ways of reading esse commune in Thomas already presuppose something about the primary meaning of being; the first presupposes that substance is primary, the second presupposes that participation in God's self-subsisting act of existence is primary. The question remains then of what is it that a phenomenological interpretation of the horizon as it shows itself can add to the notion of esse commune?

If we turn back to the experience of the horizon as it shows itself we find that the common unity of inter-action is grounded upon an intrinsic interdependency of each individual act of existence. Everywhere we look we find individual acts that have their act only insofar as another act is there for it. On my bushwalk, I discover trees whose individual existence depends upon cracks and crevices in the cliff face, birds which depend on the tree for theirs, and so on … Everywhere I walk, the individual entities that are manifest are all unified through interactions of dependency. What Thomas calls esse commune, as such, is arguably the way in which the horizon of experience shows itself as a community of interaction and interdependency through which individual entities have their act of existence.

We can dig deeper into this interdependency by stopping for a moment at an individual entity and examining how it is interdependent on other acts and activities of existence. Take for example a gum tree whose act of existence is located at the edge of a cliff. The gum which has its existence at the edge of a cliff is constantly buffeted by the wind and is pelted at times by rain driven at an angle by that same wind. The gum tree at the edge of the cliff grows roots into rock not soil, and is more often than not dependent on water which seeps through cracks in the rocks. We do not necessarily encounter these interactions in the showing itself of the gum tree which exists on the edge of the cliff. On the other hand, the individual act of the tree which we encounter bears all the signs of these encounters and is received and delimited in part by these interactions. Thus it is the case that a gum tree by the edge of the cliff is more often than not twisted and bent. It is shorter than other trees of the same species which exist further from the cliff side. We can see in this example some of the effects of the intrinsic interdependency of individual entities, in living things at least, but I would suggest this is also the case for non-living things in the same fashion.Footnote ⁴⁹ In this case, the horizon to some degree determines and delimits the specificity of the individual act.

I would suggest, then, that a phenomenological interpretation of the horizon of experience allows new ways of unpacking and re-interpreting Thomas’ notion of esse commune. We can say initially that we encounter the horizon as a community of interaction which is a real common unity without itself having an individual act of existence. Esse commune, therefore, can be posited as the showing itself of community via interactivity. Additionally, we can also say that we encounter in the horizon, as it shows itself, a community of entities grounded upon relations of inter-dependency. Thus, esse commune can also be posited as the showing itself of the intrinsic interdependency of individual acts of existence. Finally, when we turn to the way individual acts show themselves within the horizon, we find that individual acts have their act in part delimited and determined by their horizon. Here, the horizon is not the ‘reason why’ of the individual act of an entity, but rather, is the delimitation of its specific act and activity through its interactions with its environment. Thus, esse commune can be unpacked and reinterpreted as the determination of the specificity of the received individual act.

There still remains an unresolved question in the showing itself of identity and community, namely: the ‘reason why’ of the integrity of both identity and community. In order to answer this question we would need to bridge the ontological difference between the manifest and being. This would only be possible on the basis of a phenomenological investigation of Thomas’ notion of analogy.