From the ongoing drafts of Searching for the Cosmos.
Let’s say that the universe or cosmos is the unity of order of all mobile beings according to place, duration, and causality. What is a “unity of order”? A “unity of order” is dependent upon a certain type of relation, in this case a certain relationship among parts and wholes. So, we should first consider parts and wholes as preparation for thinking about the unity of order of the cosmos.
Thinking about parts and wholes
There are various meanings of “part” and “whole” in St. Thomas’s thought (integral, potestative, and universal, as well as formal and material). Aquinas also uses various analogies for the universe so as to begin with what is more known to us: an army, a house, and a household. These are all characterized by certain types of parts and wholes. However, these basic distinctions and analogies were not Aquinas’s last word on the subject of the cosmos’s composition. Rather, he extends the analogies for the universe and descends to various levels of detail. The lesson to be drawn from these passages is the multiple-realizability of these notions for the sake of contemporary insight into the parts of the universe and their constitution.
The first analogy is found in Aquinas’ commentary on Pseudo-Dionysius’s On the Divine Names (hereafter, Dionysius). St. Thomas compares the universe to a house and uses this analogy to indicate four features the parts of the universe require in order to compose a universe. We will consider them as candidates for necessary conditions for being a universe. Some even states that these provide four conditions for the possibility of a universe.
In this part of the commentary, Aquinas is considering the causality of the beautiful itself, namely, God. The beautiful is a cause of being, of unity, of order, and of motion and rest among all things. Clearly, the context is cosmological as much as theological. In particular, the beautiful is a cause of order through a providential hierarchy over beings existing in themselves as well as dwelling in one another. The four conditions in question are elaborated when St. Thomas is discussing this notion of mutual indwelling. Despite the clearly metaphysical and theological context of these four, they are nonetheless introduced with the line “Whence, it should be known that, . . . .” The sequence of four are pedagogically preparatory, and, as such, must be commonly accessible apart from their context.
The first requirement “when something must be constituted from some other things” is a communion of parts, explained as follows:
First of all it is required that the parts must come together [conveniant], just as many stones out of which a house is built come together among themselves; likewise, all the parts of the universe come together in the notion of existing [in ratione existendi].
This first part of the analogy informs us that, whatever the parts of the universe are, they must “come together” in the sense that they all have something in common. They are all destined to be parts in the same whole, the same building, all at the same time. Explaining this common ratio existendi is the burden of the cosmologist, philosophical or not. Aquinas proceeds to explain this common notion of existing in terms of participation, but this result cannot be presumed here. Indeed, each of the philosophical schools of cosmology propose a common notion of existence in their discussions of the universe.
The second, coadaptation of parts, is as follows:
Second, it is required that the parts, even as they are diverse, be able to be joined together [invicem coaptari possint]. For a house does not arise out of cement and stones unless they be fitted together; likewise, the parts of the universe are fitted together [partes universi coaptantur] insofar as they are able to fall under one order.
This second level of the analogy tells us that the parts must not only “come together”—for the parts of a universal whole can do this—but they must be joined together or “fit together.” The universe is not a mere heap of parts in a common place, but the parts are all joined together in a certain definite order. This means that the parts will be disposed towards each other in various ways.
The third, cooperation of parts, is as follows:
Third it is required that one part be aided by the others, just as the walls and the roof of a house are supported by the foundation, and the roof works together with the walls and foundation; likewise, the superior things in the universe give perfection to the inferior things, and the inferior things manifest the power of the superior things.
This third layer of the analogy is important because we are thinking about the parts of a house not merely as parts that fit together, but fit together into a common function and purpose, a “working together.” The parts of the house have different roles and some are more “foundational” than others. Are the parts of the real universe thus mutually arranged?
This mutual cooperation of parts is a sort of strengthening. Aquinas elaborates a fourfold type of “strengthening,” elsewhere in the same commentary when discussing the omnipotence of God. The first three of these modes are the most relevant here, but I include the fourth also:
[Dionysius] mentions four ways in which something is strengthened [firmatur]. A thing is strengthened insofar as it is in its natural place; whence all natural bodies rest in their place—and hence he says, and gathering [collocans]. Again, some things are strengthened by something which undergirds them, as the walls of a house are supported by the foundation and a column by the base—and thus he says, and founding [fundans]. Further, certain things are strengthened by a band, as it clear in the case of barrels—and so he says, and binding about [circumstringens].
And these three modes of strength pertain to the fact that one thing is strengthened by another, for arrangement [locatio] in the universe can pertain to this, insofar as inferior creatures are strengthened in a certain way through superior ones, which are the place of the inferiors (just as the heavenly bodies to the inferior bodies); there is foundation [in the universe] insofar as forms are founded [fundantur] in matter and accidents in subjects; and there is a binding [circumstrictio] [in the universe] insofar as the elements are established [firmantur] in mixed bodies and, universally, all parts in a whole.
Now, the fourth mode of strength is insofar as each thing whatsoever has strength in its nature—and hence he says, and perfecting in Himself every firm thing. Or it could be said in another way that the divine session gathers and founds and binds, strengthening all things itself, as if to say: God himself is the place and foundation and bond connecting all things.
The first three modes of strengthening of one part with respect to another, namely, gathering or arranging, founding, and binding, are in Aquinas’ exposition clear aspects of how one part of the physical universe aids another. The more metaphysical fourth mode, the “confirmation” of natures, regards God’s relationship to the parts. Since God is not another part of the whole, this is not of a piece with the other three. Thus, in arranging, founding, and binding, the cooperation or mutual aid of parts (the third requirement for being a part of the universe) is given various modality, three ways in which parts cooperate to constitute a whole through order. Now, while Aquinas instantiates these modes through medieval cosmology, it does not necessarily follow that these three modes themselves are restricted to that cosmology.
The fourth requirement for being a part in the universe is harmony or proportion of parts:
Fourth, a due proportion in the parts is required, namely that the foundation be such so as to be congruent with the other parts—and so he says and the harmony of each thing, that is, of all the parts of the universe. For harmony is caused in sounds from a due numerical proportion.
This fourth and final aspect of the analogy between the universe and the house completes all that goes before it. Not only must the parts come together under a common notion of existing, not only must they fit together in a certain real order, and not only must they work or operate together, but they must be, fit, and act together in due proportion. No part must be louder and stronger or softer and weaker than it is supposed to be. This is a type of harmony, St. Thomas points out, just like the harmonies in music. Indeed, here is another analogy for the universe. Even though there were no symphonies in his day, there was polyphony: the universe is like a song in many parts.
St. Thomas ends this passage by noting that, given these four modes of parts being in the whole, the whole also exists:
The parts being thus disposed, their composition in the whole follows, insofar as from all the parts of the universe is composed one totality of things—and so [Dionysius] adds, in all things—that is, in the universe—concretions [concretiones].”
All four aspects are required of its parts for the universe to be a true universe, a totality, and, if they are present, they suffice for a universe. Thus, to St. Thomas’s mind, these four are necessary and sufficient conditions for the parts of a universe. Yet Aquinas is not finished. He adds the following clarification concerning the “concretion” of parts in a whole:
Now, this concretion of parts in the universe applies in two ways: first of all, by way of the containment of place, insofar as what is superior among beings is in some way the place of inferior ones, whether spiritual or corporeal—and so he adds: indissoluble containments of existents, namely, insofar as superior things contain inferior ones by an indissoluble order. Second, [this concretion] applies to the succession of time, albeit with regard to generable and corruptible things in which there is a succession of before and after—and so he adds, unceasing successions of things which come to be. However, the successions of things are called unceasing not because these genera last forever, but because certain things succeed without alteration as long as the course of this world lasts. However, he says that all these things are caused from beauty, insofar as they pertain to the notion of harmony, which is the notion of beauty.
The universe is concretized, its parts sealed and finished, in two ways: hierarchically and temporally. First, note that even Aquinas is using a transferred sense of “containment,” in place and causality. Superior things contain inferior ones in place, and superior beings contain inferior ones in orders of causality. Second, there is a temporal concretization to the universe which joins the host of processes in it together to form a certain whole of succession, a temporal harmony. That Aquinas supplies his own examples as commonplaces from medieval cosmology is not itself an argument that they are thereby restricted to that discarded image of the world.
These four requirements for the parts of the whole universe, and how the parts must relate to other parts so as to constitute a single universe, can be usefully compared to the four aspects of how God arranges the parts of the universe, and the “foundational part” in particular, as agent cause. Aquinas details these in his commentary on Job 38:4–7, reading this passage as an argument against those philosophers who “did not attribute the position of the earth and of the other elements to some ordering plan, but to material necessity.” In the text, Aquinas finds four ways in which an architect (artifex) puts order into a building. Thus, again, the pedagogical mode of these four allow them to be useful for our purposes in some measure of separation from the theological context:
Consider that an architect puts four things in order in the foundation of a building. First, he orders the size of the foundation. In the same way, divine reason has disposed how great a quantity the earth should have, and not more or less. He expresses this, saying, who determined its measurements [quis posuit mensuras eius], in all its dimensions. He clearly says, determined [posuit], for earth by its nature does not require a certain quantity by necessity, but this quantity was only imposed on the earth from divine reason, which man cannot know. So He says, if you know it, since man cannot know or tell this. Second, the architect through his plans disposes a determinate site for the foundation, which he encompasses by the extension of the measuring line, and so He says, or who stretched the measuring line upon the earth? This means the plan of divine government, which clearly determined the place of the earth [situm terrae] in the composition [partibus] of the universe. Third, after the architect has determined the size of the foundation and where it must be located, he determines how to make the foundation solid. As to this He says, on what were the bases, of the land, sunk, because it was founded on the center of the world. Fourth, after these three things, the architect now begins to lay the stones in the foundation, beginning with the corner stone, on which all the different walls are aligned. As to this He says, or who has laid, put down, the cornerstone, on which the very center of the earth is clearly determined, according to which the different parts of the land are aligned [connectuntur].
The four, in summary, regard the determination of certain parts of the universe as a whole insofar as these are related to a foundational part. The foundation is considered with these parts in mind, and it must be determined as to its quantity, location, natural stability or permanence, and brought into existence. Again, despite the clearly geocentric details of Aquinas’ commentary, these do not prevent these four marks from being realized in a different manner. The genesis of the universe from a principal “part” is analogized to the construction of a house from its foundation. The determination of the quantitative measurements of the parts of the world are not by material necessity but through contingency limited by design. This contingency of parts within the whole has been noted by thinkers contemporary to Aquinas as well as by our own contemporaries.
Let us briefly recapitulate these analogies and the three sets of four that can be drawn from them. Flowing overall from an analogy to housebuilding, Aquinas draws out an array of mereological relationships that he uses as the basis of analogies for the universe as a whole and its parts. The first set concerns the parts within the whole; the second set considers the parts in their relationship to each other; the third considers the architect’s work regarding the parts, especially the principal part or foundation (see Table 3.2).
|Parts composing the whole||* Parts strengthening parts||† The whole’s foundation|
|In Div. Nom., n. 364||In Div. Nom., n. 851||Super Iob, cap. 38|
|communion of parts||arranging the parts||determination of quantity|
|coadaptation of parts||founding the parts†||determination of place|
|cooperation of parts*||binding the parts||determination of stability|
|proportion of parts||God confirming natures||making the foundation|
The second set expands upon the idea of cooperation or joint function of the parts within the whole. The third set expands upon the second item of the second set, the idea that certain parts serve as the foundations for other parts.
What lessons can be drawn from the above? The first lesson is the multiple-realizability of the notions in Table 3.2. That is, since Aquinas proposes them in a pedagogical mode, he is relying upon their analogical illustrative power independent from the way in which he instantiates them through medieval cosmology. It is no small part of the task of this book to substantiate how these notions are relevant to contemporary cosmology. Indeed, insofar as we can return to these beginnings repeatedly, they provide the basis for a perennial philosophy of cosmology.
The second lesson is the more important one for present purposes. The notions in Table 3.2 illustrate how the parts composing the whole universe constitute a unity through their mutual ordering to each other. This order is not merely in place and time, but most especially through causality, and not only agent causality, but all four Aristotelian causes. Thus, the lesson to be drawn about part-whole relationships in the universe is that the quasi-genus of the cosmos, unity of order, is a notion that emerges from a web of causal relationships. Let us explore this result more fully.
What it means to be unified by order
The unity of order (unitas ordinis) is the least of the sorts of unity. Yet, at the same time, it is the unity of the world, “for this world is said to be one by a unity of order, insofar as certain things are ordained to others.” Now, order itself is a notion that includes before and after (priority and posteriority).
Order includes three notions in its definition. First, [it includes] the notion of before and after; whence, according to all of those modes [of before and after] one is able to say that there is an order of things, insofar as some thing is said to be before another (according to place, time, and all the others of this sort). Order also includes [the notion] of distinction, because there is no order of things unless [they are] distinct. Yet the name “order” rather presupposes this than signifies it. Also, [it includes], third, the notion of order from which the species of order is drawn. Whence, one is an order according to place, another according to dignity, another according to origin, and so forth with the rest.
In this passage, St. Thomas alludes to the various sense of “before” in the twelfth chapter of Aristotle’s Categories. These senses of “before” or “prior” (and, consequently, “after” or “posterior”) are before in time, in being, in reason, in nobility, and in causality. Now, what Aquinas does not say in this passage is that a unity due to order arises automatically in each case. Presumably, this would depend not only upon the sort of priority and posteriority involved, but the nature of the things distinguished and potentially having such a species of order.
Which species of order most clearly gives rise to a unity of order? The better known examples of this “unity of order” are in human affairs, such as a family, a sports team, a symphony, and the like. Aquinas explains this in a passage from the beginning of his commentary on Aristotle’s Nicomachean Ethics, a text worth quoting at length:
This whole which a civil multitude is, or a family, has a unity of order alone, insofar as it is not something one simply speaking. Thus, the parts of this whole are able to have an operation which is not the operation of the whole, just as a soldier in an army has an operation not belonging to the whole army. Nonetheless, this whole also has some operation which is not proper to some part but to the whole, namely, the engagement of the whole army. The hauling of a ship is the operation of that multitude drawing it.
However, there is another whole which has unity not only by order but by composition or by conjoining, or even by continuity (according to which unity something is one simply speaking), and thus there is no operation of the parts which does not belong to the whole. For in continuous things the motion of the whole and of the part is the same, and likewise in composed or conjoined things the operation of the parts belongs principally to the whole. Thus, it is necessary that the consideration of such a whole and its parts belong to the same science; however, it does not belongs to the same science to consider the whole and parts of that which has a unity of order alone.
The main conclusion of these analogies is directed towards clarifying how ethics differs from other parts of moral philosophy, such as politics. However, the general principle illustrated is that the unity arising from parts in a whole comes in a gradation of strengths (cooperation, composition or conjoining, and continuity), and the stronger the unity the more properly does the action of the parts belong to the whole. A whole whose parts are more distinct and independent is one whose operation emerges from the parts but belongs to the whole: the army or city or family has an activity which cannot be reduced to any one part but depends upon all of them collectively. Thus, the nature of a whole which has unity “by order [ordine]” depends upon the nature of this relationship between its parts, in contrast to cases where the form of the whole has more causal priority.
This is evident in another analogy where St. Thomas employs the idea of a unity of order, in Quodlibet VIII, q. 3. The question concerns whether or not food is truly converted into human nature. After reviewing and rejecting two other opinions, Aquinas answers in the affirmative, making this analogy along the way:
For just as in a given republic a number of different men belong to the community, certain ones of them dying and others taking their places, and thus, according to matter the republic does not remain one (because there are at first some men and then others), nevertheless, it remains one in number according to its species or form on account of the unity of order in its distinct offices, so too in the human body also the flesh and bone and each of the parts whatsoever remain the same in number according to species or form (considered in a determinate site and power and figure), yet each part does not remain as to matter (because the matter of flesh in which such a form was previously is spent, and more takes its place). This is clear in the case of fire, which is renewed as to the same form or mode by this means, that, a certain amount of firewood being consumed, more is supplied which sustains the fire.
The basis of this analogy is a reference to Aristotle’s conclusion in the Politics that a polis is the same not in virtue of the generations of its citizens, but in virtue of the continuation of its form, namely, its regime, including its various offices. The relationships among these civic offices, functions, and duties are analogized to the arrangement (situ), power, and figure of the parts of the human body. The analogy does limp, however, since the city, unlike the human body, does not possess a substantial form. The human body is not first made one by a unity of order, even if it exhibits, at the level of its accidents, such unities of order (for what the analogy is meant to indicate is that the order among the powers and parts of the body—a sort of homeostasis—is dynamically maintained as to its form but not as to its material composition). Likewise, the closing analogy to fire is meant to illuminate the overall analogy concerning how a resultant form can be a certain invariant across varying matter.
From both of these analogies (and the examples of a city, a household, an army, and hauling a ship), it is clear that something is one by a unity of order when its parts exist in some way before the whole which they compose and have some bearing upon each other such that from their mutual relationship or interaction there emerges a certain order (in most examples, a unity that bears a common action). Particularly, in these examples, the order arises not from time or place or the consideration of the mind, but from causality.
That the universe is made one by causality is confirmed when looking at contexts where St. Thomas discusses the universe as unified by order. For instance, speaking about “the order of the universe,” Aquinas notes that “if actions are taken away from things, the order of things to each other is taken away, for among things which are diverse in nature there is no connection in a unity of order unless some act and others are acted upon.” Thus, a unity of order arises in the cosmos due to agent causality. In another place, he observes that “in creatures one does not find one form in many individuals except a unity of order, as the form of an ordered multitude.” Thus, formal and material causality are also involved in the unity of order of the cosmos. That is not all, “for this world is said to be one by a unity of order, insofar as certain things are ordained to others,” which implies final causality. Exemplar causality is included also, for “creatures are like unto God in unity, insofar as each one is one in itself and insofar as all are one by a unity of order.”
 See St. Thomas, In Div. Nom., c. 4, lect. 6, n. 364. The translations from the text quoted below are my own modifications of the Hannon translation, with consultation of Marsh.
 St. Thomas, In Div. Nom., c. 4, lect. 6, n. 359.
 Ibid., n. 364.
 St. Thomas, In Div. Nom., c. 10, lect. 1, n. 851.
 St. Thomas, In Div. Nom., n. 364.
 St. Thomas, In Div. Nom., n. 364.
 St. Thomas, In Div. Nom., n. 365.
 “Where were you when I laid the foundation of the earth? Tell me, if you have understanding. Who determined its measurements, if you know it? Or who stretched the measuring line upon the earth? On what were the bases of the land sunk or who has laid the cornerstone when the morning stars praised me, and all the sons of God shouted for joy?”]
 St. Thomas, Super Iob, c. 38, lect. 1, n. 495; Mullady translation.
 Ibid., n. 495; translation slightly modified.
 See St. Thomas, ScG, II.58: “Unitas ordinis sit minima unitatum.” (Leon.13.409)
 St. Thomas, ST, Ia, q. 47, a. 3, c.
 St. Thomas, In Sent., lib. I, d. 20, q. 1, a. 3, sol. 1.
 St. Thomas, Sent. Ethic., lib. I, lect. 1, n. 5.
 Note, first, however, that in other texts composition or conjoining (colligatio) are used interchangeably with the unity arising from order. However, this breadth of sense occurs in English as well. Second, this passage does help one understand why St. Thomas calls the unity of order the least sort of unity.
 St. Thomas, Quodlibet VIII, q. 3, c.
 See Aristotle, Politics, III.3.
 Perhaps for this reason St. Thomas calls the unity of order the least sort of unity, for it arises due to causal relationships between things which already possess substantial unity, and “relation has the least share of being among the genera.” See De Pot., q. 9, a. 5, ad 2; see also In Sent., lib. 3, d. 2, q. 2, a. 2, sol. 3. c.
 St. Thomas, ScG, III.69, n. 17.
 St. Thomas, ST, Ia, q. 39, a. 3, c.
 Ibid., q. 47, a. 3, c.
 St. Thomas, De Pot., q. 3, a. 16, ad 2; see ibid., obj. 2 and 10.