On Aristotle’s Doctrine of Elements

The Aristotelian cosmos is composed of moving elements. An understanding of these motions of elements is necessary for an understanding of Aristotle’s cosmology. Therefore, in this paper, I will briefly examine the question: what is Aristotle’s doctrine of moving elements?

Motion, according to Aristotle in his Physics, is the ‘activation of potency qua potency’ (Physics, III 1, 201a 10). To inquire into any kind of motion, therefore, is to inquire into the activity and potency that belong to the moving thing. Both activity and potency are facets that delineate the thinghood of a thing. But what kind of thing is an element?

Elements are simple and natural bodies. They are thereby distinguished from artifacts and composites. Being bodies, these elements have certain forms and activities. Hence elements are not pure material (ὕλη). Moreover, since most elements are inanimate, their motions should be distinguished from those of animals. It is against these four, i.e. artifacts, composites, matter and animals, therefore, the genus of elements is to be determined and clarified.

1. Contra Artifacts

Different from artifacts, natural bodies have physical forms preceding them; human beings are born from human beings, but chairs are not born from chairs. According to Aristotle, elements are neither actualized from nor put into work by the sources in the soul (Metaphysics, VII 7, 1032b 1), but the sources of their motions pre-exist physically as localized principles of formation or teleological destinations, i.e. natural places. These always extant physical forms of the elements are pre-ordered into a topological hierarchy,

But since place is the limit of what encompasses, and the extremity and the center encompass all the things moving upward and downward, it in a certain way becomes the form of what is encompassed, it is to its like that a body moves when it moves to its own place. (De Caelo, IV 3, 310b 5)

And we say that what encompasses pertains to form, what is encompassed to matter. And this distinction exists in every genus. For in [the category] of quality as in of quantity, there is what is more the way form is, and what is more the way matter is. And in the case of what has to do with place it is the same way: up pertains to what is defined, down pertains to matter. (De Caelo, IV 4, 312a 10)

Elements move to their natural place to be fully actualized among their own kind. We could conceive of this ordering in such terms as if the ordered cosmos were an animal. This does not stray far from the Aristotelian doctrine, since one cannot maintain that Aristotle necessarily believes the cosmos to be inanimate, as he ascribes life to the outermost sphere and categories such as ‘right’ and ‘left’, which only properly belong to animate things, to this heaven (De Caelo, II 2). This conception, analogical at least, is helpful. Elements in their right place can therefore be conceived as organs of this eternal animal, which have their own organic, functional forms that distinguish each from the others. These natural places are, accordingly, not uniform spaces, but are boundaries, as Aristotle always insists, that both encompass and form bodies into ‘organs’.

To trace the history of elements and their motions, we start from when one such simple body first comes to be. Let us suppose a particular fire is generated among other particular earth elements. This nascent fire is already stabilized in its form, but this form has not yet been fully actualized. This form of fire is ‘what is more the way form is’, the most form-like form, and hence the form of the most encompassing. This ‘encompassing-ness’ of fire, in its gradual actualization, sustains its upward motion, so that as it arrives at the extremity of the cosmos, it is fire. The same works for earth, which has the most material form, and only is earth when it arrives at the place where it is the most encompassed, namely, the center. The center of the cosmos is therefore indeed a limit and a formative principle, but it only pertains to the least form-like form. Intermediate between fire and earth are air and water. This ordering of the cosmos is always extant, though elements come to be and pass away, because, formally, the outermost sphere neither comes to be nor passes away, and its shape always ordains the same hierarchy of formations, i.e. extremity (the most encompassing), middle (the intermediary), center (the most encompassed); physically, elements only transform among themselves, but do not all pass away at once, so that there always remains the matter out of which the ordered cosmos is to be recomposed, and the order is always maintained as a whole in its potency; moreover, since it is highly unlikely that there is one such instant in which the universe is totally devoid of one element so that all of one element is transformed into others, one is safe to assume that the order is also maintained in its actuality.

Two other things are noteworthy about this pre-established order. First, this ordering is potentially infinite,

For there is nothing to prevent there being one or more intermediates between the contraries, as in the case of colors. For ‘intermediate’ and ‘center’ are said of things in many ways. (De Caelo, IV 5, 312a 30)

The preliminary division of the order into four primary places is therefore permeated by all kinds of mediation and gray areas. Second, this order is asymmetrical. Such asymmetry is most manifest in the intermediate elements,

Each of the bodies having both heaviness and lightness, then, has heaviness in its own space (whereas earth has heaviness everywhere), but does not have lightness, except in those in which it rises.

That is also why if a supporting body is removed each spatially moves to the body next below it, air to the space of water, water to that of earth. But air will not spatially move upward into the space of fire, if the fire is done away with, except by force...... (De Caelo, IV 5, 312b 1)

The intermediate elements never naturally move up. This displays an asymmetry between the encompassing and the encompassed, the forming and the formed. When material is lacking, lower forms descend in order to replace the material, yet when higher forms are lacking, these lower forms do not elevate themselves. Lower forms are only elevated when the material is profuse, like water expelled by earth from the center is pushed upwards. But is this upward push a compulsion? If so, how can the middle be a natural place for water, when water is only compelled by earth to move there? The intermediates therefore display a curious structure of nature and compulsion that is dependent upon the structure of form and matter. At this point we can only conjecture what such asymmetry implies metaphysically, if there is any such thing implied. To make this asymmetry between form and matter more explicit, since water has a nature to form earth and be formed by air, once earth is lacking, water is left as the most material form among the rest of elements, and is to be used as matter and formed at the center. Yet when fire is lacking, air does not move upward. So it seems that a form is easily converted into material by a higher form when matter is lacking, but what is used as matter is not easily converted in the reverse direction, in the same sense that a general can easily replace a soldier, but he ought not to replace his king. To convert matter into form is therefore unnatural, and can only be done through compulsion. Water is only pushed upward by the profuse matter, the profuseness of which forces water to be more encompassing and more form-like. Yet from this it does not follow that air, water and earth all share the same natural place (the center), if only earth is more compelling than others and is able to force others out of that shared space. As it is unlikely that at any moment the center is totally devoid of earth, the natural cosmic order almost always persists, and each element is assigned to its usual place. But since what is natural is in a way what is usual, any change in this ordering is in this sense incidental to nature, and where water stays usually, hence, is where it should stay naturally. Moreover, water is indeed compelled by earth to move upwards, but only in an insignificant sense. For it is natural of water, the second lowest form, to be ‘compelled upwards when earth, the lowest form, is present’, but ‘descend when such material is lacking’. The same structure inheres in air,

For air is naturally both light and heavy. Insofar as it is light, it produces spatial movement upward, when it is pushed and gets a starting-point [of movement] from a capacity, and again downward insofar as it is heavy. (De Caelo, III 2, 301b 20)

To fully elucidate this structure, it would be helpful to consider that, for Aristotle, the potency of a particular thing is to a large extent already determined by the being of this thing. In a similar vein, the structure laid out here ordains that the way a thing is to be compelled by another thing is already inherent in the nature of this thing. It is the nature of water to be compelled upwards by earth, just as it is the nature of air to be also easily compelled. ‘The very capacity to be compelled in some specific way by some specific other thing’ thus belongs to the very nature of a thing. This is so for water and air as well. However, these natures are not arbitrarily dictated. Rather, they cohere with the asymmetry between form and matter: just as it is ‘reasonable’ (ἔυλογον) for a lower form to only be elevated when it is compelled, but to descend into material when no such compulsion is present, it is ‘natural’ for water to rise when earth is present and profuse, and fall when earth is lacking. Insofar as elements are compared to artifacts, therefore, I hope I have successfully laid out the pre-established cosmic order which is physically extant and which determines, topologically, the sources of the motions of these elements. Such an order is different from the order inherent in the soul, whence only artifacts come to be.

2. Contra Composites

Elements are simple bodies. Their simplicity consists, most primarily, in their forms. It is therefore from their simplicity of form we should derive their simplicity of motion. However, Aristotle never provides an explicit argument that helps us see how the simplicity of motion is to be necessitated by the simplicity of form. For him, it seems to be a natural conclusion that a simple body shall move simply. We are not sure if this is only a premise taken for granted, or if he has either metaphysical or physical reasons to believe that this is the case. Anyhow, we can easily imagine simple bodies move randomly in an infinitely intricate way, as Democritus and Plato both did, and question how might Aristotle exclude such a conception from his cosmology.

We start from forms of body. Three principles can be abstracted from a body, length, breadth and depth. Length by itself generates lines, together with breadth generates surfaces, with both breadth and depth generates complete bodies. Yet these principles are ways in which a body is complete and continuous, but are not distinct forms of body. For any part of a body is constituted by these three dimensions. These dimensions alone therefore do not differentiate one part of body from another, but only bodies in general from other kinds of magnitudes. Yet a form is supposed to be that difference which describes a species out of its genus, and our genus here is one singular body, i.e. the cosmos, and not magnitude in general. Accordingly, the only forms we can resort to here in order to differentiate one part of body from the others are the following: starting-point, middle and end. Starting-point is that which is the most material and encompassed, whereas end is that which is the definition and the highest form. The most encompassed part of a body is its center, and the definition of a body is its extreme surface. Therefore, the most primary forms correspond to the three primary places, i.e. center, intermediary, and extremity, as I have maintained in the first section of this paper. The simplicity of form is manifest in the simplicity of place. What remains is to include the simplicity of motion into this relationship as well.

A simple body has a simple nature. This means that it only has one singular form to actualize. Consequently, by its nature, fire should do nothing else but arrive at the extremity, at least in terms of locomotion. Yet what does it mean for fire to ‘do nothing else but arrive at the extremity’? It means, first of all, that any wandering or aberrant course is forbidden to fire. Fire has to always move, by its nature, in the shortest path to arrive at its natural destination. Since fire moves between two contraries, namely, the center and the extremity, the shortest path of its motion is necessarily a straight line. It is due to this the geometrical simplicity of straight lines is added to the simplicity of the nature of a body, and not because straight lines and elements share a nominal sameness in their respective ‘simplicity’. In other words, it is not because elements are simple bodies that partake of simplicity in one way (formal simplicity) that they have to, by this reason alone, have linear motions that partake of simplicity in another way (geometrical simplicity). For the unique thing about their motion is not that they move linearly, but rather that they move ‘up’ and ‘down’ in the shortest path possible to their natural destination. The geometrical simplicity is there only in service to the simplicity of form. Otherwise, if it is the geometrical simplicity alone that satisfies the requirement, earth could move down to the center in an arc, since a circular path is also geometrically simple, or move linearly, but at a dissimilar angle to reach the central region. Yet neither actually happens, and earth elements always move directly downward (De Caelo, II 14, 296b 15), i.e. neither in arcs nor in parallel but in straight lines at similar angles, so that they reach their destination in the shortest path possible, and have the center and nowhere else, not even the neighborhood of center, as their sole target.

The fifth element, viz aether, can also be conceived partially under the same schema. Aether has one singular nature, namely, to encompass the All. This nature is eternal and has no contrary. The singularity of this nature therefore requires that aether does nothing but to always encompass, and if it moves, to always move in an encompassing way. On this account, aether can be formed in no other shape but a sphere, and can move no other way but circularly. For sphere is the primary shape that encompasses. It of all bodies with a given surface area encompasses the most space, and a circle of all planes with a given circumference encompasses the greatest area, as demonstrated by Archimedes. Though earlier than Archimedes, this property of spheres and circles is probably also known to Aristotle (De Caelo, II 4, 287a 25). The sphere is the primary encompassing thing also because it encompasses singularly and completely, whereas other rectilinear shapes rely upon several surfaces, each of which can be produced indefinitely (De Caelo, II 4, 286b 10). Therefore, compared to the sphere, other bodies are not formed simply to encompass, but all have their redundancies. Just as earth takes the shortest path to actualize its form most simply, aether is shaped and moved in the simplest way to actualize its end of ‘encompassing’. The simplicity of elemental motions is hence to be understood as a real, viz not nominal, consequence of the simplicity of their nature. Aether is shaped and moved simply, not because it, being a simple body, by this determination alone should be simple in every aspect. But rather that the spherical shape and the circular motion are the ‘most effective ways’ for aether to actualize its singular nature, so that through these, aether does nothing redundant but to bring out its form. To use Leibniz’s terms, these simplicities do not cohere merely because they are all called ‘simplicities’, but because they follow upon each other via the principle of sufficient reason.

3. Contra Matter

Elements are bodies, but bodies are not matter. Though elements can be used as matter by higher forms, as earth is formed and encompassed by water, they are separate from matter as such. In De Caelo, the relationship elements have to matter is the most clear in their coming to be and their motion. This is reasonable, since for Aristotle, the matter of a thing is synonymous to the potency a thing possesses. Consequently, to inquire, with respect to matter, into the coming to be of an element in contradistinction to its motion is the same as to inquire into the respective structures of activity versus potency an element has, in its coming to be as opposed to moving.

First, when an element comes to be,

For just as in other cases the underlying subject must be formless and shapeless (for in this condition it would be most capable of receiving shape, like the ‘all-receptive’ written about in the Timaeus), in the same way too the elements must be considered as matter. That is why indeed, being separate from their qualitative differences, they are capable of changing into each other. (De Caelo, III 8, 306b 15)

A few things can be concluded from the passage above. An element comes to be through other elements and among other elements. Yet during this coming to be, there is no matter actually separate from these elements. For if so, this matter shall either be an element by its own right or an absurd being that is without any quality (De Caelo, III 6, 305a 20). Therefore, in its coming to be, an element has its nature or quality imprinted onto the totality of its matter, so that no remainder of matter should be able to be separated from this being. Earth is only divisible into earth, and any part of fire is still fire (De Caelo, III 3, 302a 15).

The nature or form matter receives when an element comes to be is a mixture of contraries. This conforms to the general schema Aristotle lays out in his Metaphysics (Metaphysics, XII). Fire is formed only in lightness, earth only in heaviness, whereas water and air in a mixture of both. The all receptive matter is imprinted more or less by these two contraries. This ‘more or less’, however, is not due to the amount of matter taken up by the form, since magnitude is itself a form, but how well or distinctly a form is imprinted to the matter. As one form takes up the matter more well and distinctly, its contrary should take up the same matter less so. Moreover, since a form and its contrary can be thought of as the presence and absence of one singular form, the more a form is present in matter, the less matter-like a formed thing is, and vice versa. It is in this way Aristotle can first interpret the opposition between earth and fire as an opposition between the less form-like and the more form-like. Nonetheless, one should bear in mind that whether a form is like matter or not has no bearing on its absolute form-ness, so to speak. The form of earth, despite being matter-like, still remains an active principle, and earth always moves to be formed at the center nonetheless. Thus, we can conclude that in coming to be, an element has its nature imprinted onto the totality of its matter, while its nature is a mixture of two contraries. The potency of an element here is therefore a transformative potency. Just as in coming to be matter receives a nature, so is the matter of an element equally receptive of a different nature. These received natures are active principles, not passive ones. Water and air have both heaviness and lightness, and these two contraries are both active in either one of them. Via such receptiveness of matter, therefore, elements always have the potency to transform into each other.

However, when elements move spatially, a different aspect of their matter is emphasized,

Yes, and since the same thing that is capable of being made healthy is receptive of disease, if it is moved insofar as it is capable of being made healthy, it moves toward health, if it is moved insofar as it is [capable of being made] diseased, toward disease. But the heavy and light, more than these, appear to have within themselves the starting-point, because their matter is closer to substance. A sign of this is that spatial movement belongs to independent things, and in coming to be is the last of the movements, so that this movement would be primary with respect to substance. When, then, air comes to be from water and light from heavy, it progresses upward. And at the same time it is light, and is no longer becoming so, but in that place is. It is evident, then that being potentially, going toward actuality, it is progressing to that place, quantity, and quality where the actualization of its quantity and quality and place lie. And it is due to the same cause too that what already exists and is earth or fire moves toward its own place if there is nothing impeding it. (De Caelo, IV 3, 310b 30)

Instead of receiving a different form or active principle, matter is now a potency that only passively resists the already received nature. One shall understand this better if one recalls the Aristotelian form-matter schema. The two contrary forms are opposed to each other, whereas the underlying matter is said to oppose both contraries in quite another way. The potency of fire by which fire is either sustained in its upward motion or not is not there because this potency has received a nature contrary to that of fire, i.e. heaviness, since fire is unconditionally light, but that matter qua matter passively resists the actualization of the form of fire. This potency enables fire to be forcibly removed from the extremity, to be moved or poised contrary to its nature, or to come to be somewhere that is not its proper place, but it does not actively destroy that nature, i.e. fieriness, of the thing to which it belongs, i.e. fire. In other words, this potency is a passive potency, which is only receptive of a contrary nature to the extent that such opposition remains transitory and insignificant compared to the preponderance of its current nature. Unlike that which is indifferent to health and disease and is capable of receiving both contraries, fire, once it comes to be, can only naturally move upwards and has a preponderant inclination to do so.

Therefore, one might say that in the process of coming to be and passing away, elements have their activity and potency structured in one way, so as to receive different active principles, while in motion they have them structured in a quite different way, so as to leave room for the actualization of one already stabilized nature. It remains a question whether these two structures are communicable. The answer to this question largely hinges on how one interprets the following statement,

For nothing contrary to nature is eternal. (De Caelo, II 3, 286a 15)

If one takes this to mean nothing should impede the natural motion of a thing for all time, one in a sense answers in the negative, that locomotion has no effect on the nature of a thing. But if one takes this to also mean nothing that is continually inhibited from its natural motion and is continually forced to stay at a place where it does not belong can endure in its nature, one admits that locomotion and transformation, and their respective structures of activity and potency, are communicable, so that where a thing is determines what it shall become, and what a thing is shall determine, conversely, whereto it shall move. Indeed, this consequence seems to be implied by Aristotle himself, when he decides in his Physics that locomotion is first in time, in addition to its being first in the teleological sense, so as to cause all other motions, including coming to be (Physics, VIII 7, 260b 30), and when he organizes places by a hierarchy of formations. Therefore, I incline to take the affirmative, and speculate that at its own place, an element actualizes its own nature; removed from that place, it is positioned contrary to its nature, and its matter passively suffers from a formation too transitory and unstable to be, e.g. fire being placed at the center, which formation is contrary to its pre-stabilized nature, e.g. fieriness as lightness, in a most insignificant way; yet as this contrary formation is kept continually, it stops being merely transitory but is stabilized, thus changing the original nature of this element irreversibly: transforming fire into earth, for instance.

4. Contra Animals

Elements and animals (by animals I mean animate things) are different kinds of being,

That is why one must not look for up and down, right and left, and front and back in every body, but only in those that, being animate, have a starting-point of movement within them. For in inanimate ones we do not see the starting-point from which the movement derives (for some things do not move at all, whereas others, though they do move, do not do so in every direction alike––for example, fire moves upward only and earth toward the center). (De Caelo, II 2, 284b 30)

That is, more than anything else, animals have within themselves the starting-point of motion, whereas fire and earth do not. Yet Aristotle seems to contradict himself on this point when he later maintains that

But the heavy and light, more than these, appear to have within themselves the starting-point, because their matter is closer to substance. (De Caelo, IV 3, 310b 30)

This apparent contradiction, however, can be resolved by what directly follows upon the passage quoted above,

For nourishment too, when nothing prevents it, and what is capable of being made healthy, insofar as nothing restrains it, proceed immediately. But what causes the movement is what produces it at the start, what removed the hindrance, or from which the thing rebounded, as was said in our first accounts, in which we determined that none of these things moves itself. (De Caelo, IV 3, 311a 5)

In other words, though these simple bodies seem to have their starting-points of motion intrinsic to themselves, they nonetheless rely upon other things to initiate this motion. This statement becomes more intelligible once we notice the subtlety with which Aristotle first introduces the natural motions,

For we say that all natural bodies and magnitudes are intrinsically capable of moving with respect to place. For nature we say is the starting-point of movement for them. (De Caelo, I 2, 268b 15)

And if we conjoin this to another passage, we are equipped with all the pieces we need to finally complete the puzzle and grasp how elements are to be distinguished from animals,

Since nature is a starting-point of movement within the thing itself, a capacity is a starting-point of movement within another thing, or within the thing itself insofar as it is other, and all movement is either in accord with nature or by force, the one in accord with nature (for example, that of a stone downward), will be made faster by force, whereas the one contrary to nature will be wholly due to it. (De Caelo, III 2, 310b 15)

Like animals, elements have intrinsic formative principles that correspond to their natural places, which are formative principles localized. This principle in fire is its lightness, whose actualization requires fire to move to the extremity, where fire naturally belongs; so fire moves by itself. But fire does not transform by itself. Once fire comes to be, it is fixed in its singular form to always move upward. In this sense, fire is different from animals, that it does not move ‘in every direction alike’. Animals can move freely because their principles are transformative principles, i.e. souls that are ‘form of forms’ (De Anima, III 8, 432a 1), and animals can use their soul to change many subsidiary forms they also possess. Elements, however, only possess the locomotive principle determined by their singular nature. In other words, though elements have the potency to be transformed and be moved, they only possess the active principle for the latter. By contrast, plants, animals and human beings can always ‘transform’ so as to move to and rest at different places, overcoming the natural heaviness or lightness of their physical bodies, for even plants do take root downwards and stretch upwards inexorably; while elements can only passively undergo one determinate kind of motion due to the simplicity of their nature.

Therefore, regarding the process of transformation, elements only possess the capacity but not the principle. The transformative principle is either ‘in another thing or within the thing insofar as it is other’. This conforms to my earlier determination, that when an element is continually compelled away from its natural place, it might change in form. Fire has the capacity to be changed by others, not the nature to change on its own. But regarding the process of locomotion, elements possess both the capacity and the nature. Yet since they lack the transformative principle, of which the locomotive principle is ultimately derivative, they are not capable of removing the obstacle before them by themselves, for they do not move in a free way that can either circumvent or destroy that obstacle. Thus they rely upon incidental occurrences to actualize their nature.

I wish I have explained the distinction between animals and elements as clearly as I can. Yet this discussion only covers four of the five elements. The fifth element, i.e. aether, is exempt from the earlier determination, since this element seems to possess life,

We think about these stars as bodies only, that is, as units having a certain order, altogether inanimate. But we should conceive of them as participating in action and life. (De Caelo, II 12, 292a 20)

But if those elements that do not move freely are said to be dispossessed of life, how can aether, which also moves in a singular way, be said to ‘participate in action and life’?

Aristotle provides one possible way to answer this question. He says,

That is why one should think the action of the stars to be like that of animals and plants. For here the actions of human beings are in fact most numerous, since it is possible to attain many goods, so that it is possible to do many things in action, and for the sake of other ones. (What is in the best state, by contrast, has no need of action, since it is itself the for-the-sake-of-which......) The actions of the other animals, on the other hand, are fewer, and of the plants perhaps one small one. For either there is some one thing which they may attain, as there is for a human being too, or the many things are a route toward the best one. (De Caelo, II 12, 292b 1)

The transformative principle within all animals revolves around the ultimate end. Animals do many things only so that they can be in the best state. By contrast, heaven has already reached the best state in its eternal circular motion, and it moves not in order to become actualized in its nature, since it does not move between contraries, but to remain in its unceasing state of life and action. Of what use then is the transformative principle to it, when heaven is itself the highest form in the cosmos? Stars need no art, no instrument, no education, no custom, no freedom to move every which way, as they stay in eternal bliss and happiness. They transcend all sublunar principles, for all these principles are laborious. They subsist only in the divine,

But then neither is it reasonable that the heaven remains eternal because a soul necessitates it. For it is not possible for this sort of life to be painless and blessedly happy for a soul. For it necessarily, with respect to its movement, involves force––if indeed it moves the primary body in another way than with its natural spatial movement, and moves it continuously––and to be unleisured and deprived of all thought-involving ease, if indeed it does not have, as does the soul of mortal animals, the relaxation of the body that comes about in sleep. Instead, it is necessary that a fate of some Ixion, eternal and indefatigable, restrain it. (De Caelo, II 1, 284a 25)

Both transformation and locomotion for sublunar bodies require force. Since to transform means to change nature, transformation is necessarily contrary to some nature, if not the predominant one. And to move spatially always entails, for sublunar bodies, an overcoming of resistance. Locomotion is an adornment only for stars, but labor for all other bodies: these bodies have to move against compulsion in order to move at all. No principle for sublunar things, therefore, befits divinity. To use Aristotle’s formulation, the simplicity aether has is that of happiness, while the simplicity of the other elements is of an inferior kind, the kind which is analogous to that of plants, who are capable of doing only one thing due to their powerlessness, not due to their divinity.

To conclude, in this paper I have compared elements with artifacts, composites, matter and animals, so as to better delineate their thinghood. As opposed to artifacts, the formative principles of elements are physically extant and localized by natural places. Elements move to these natural places in order to fully actualize their forms that are already intrinsic to them as locomotive principles. Next, in contrast to composites, elements possess a formal simplicity. This formal simplicity is related to the simplicity of destination. From there, the motive simplicity of elements can be deduced via the principle of sufficient reason. Then, in contrast to matter, I distinguish two kinds of potencies elements possess. The first potency is a transformative potency, or the capacity to receive a different form. The second potency is a passive potency, or the capacity to either actualize, or not, a nature that is already within the thing. The actualization of the latter potency takes the form of locomotion, since locomotion of all motions changes a substance the least. I also speculate that these two potencies are communicable, so that when a body is poised at a place contrary to its nature long enough, it shall be destroyed by that very fact, directly or indirectly, and be transformed into something else. Following this, I distinguish elements from animals by their incapacity to transform on their own. I maintain that elements do not possess in themselves the transformative principle, but only the capacity to be transformed by something else, e.g. a place contrary to its nature, though both elements and animals possess the locomotive principle to move to their natural habitats. Such a habitat for human beings would be their city, for instance. But since animals also possess the transformative principles in themselves, i.e. souls, they can more or less change their destinations and habitats. This capacity to change, however, is limited by the ultimate end, i.e. happiness. Aether is therefore superior to all other elements and beings, since it persists in the state of happiness for all eternity. It moves leisurely, as if asleep. And the cosmos is in its arms, as if the world were but a dream by the divine.