To start, we first need to make the following observation. A movement differs from a state in that it bears a peculiar relation to its prospective end result—which it does by virtue of the movement form it instantiates, we said. A state does not in this way point towards anything. That is why movements, and hence powers, are explanatory in a way in which states are not. (As we saw, Humeans think otherwise: they reject the entire category of power, and hence of movement, and take de facto regularities among states to be explanatory.) However, the generic concept of power is silent on whether or not movements have such peculiar explanatorily relevant relations to the other ingredients: to the circumstances that trigger the manifestation, to the individual substance that bears the relevant power, to the movement form, or to the substance form. This is bound to sound obscure at this point: what could such ‘peculiar explanatorily relevant relations’ consist in? Yet, as we will now see, this is precisely where our generic power concept leaves room for articulation into several varieties of power.
Let us call powers that are adequately characterized, metaphysically speaking, by our generic power concept level-0 powers. A typical example of a substance form that comes with such level-0 powers is water: it has the power to freeze, to evaporate, to dissolve various kinds of stuff, etc. Whenever water is put in the right kinds of circumstances, it will manifest those powers, resulting in movements of the corresponding movement forms: freezings, evaporatings, dissolvings. While in progress, such movements can usually be interfered with or stopped, e.g., if the circumstances are appropriately altered.
Now, although once water is engaged in such movements, the relevant end result is already on the horizon (being fully frozen, fully evaporated, having reached saturation or having fully dissolved the relevant stuff), water simply has those powers without their manifestations thereby being ‘on the horizon’. That is to say, although water will behave in accordance with its powers in any circumstance, it is completely indifferent as to which circumstances it will find itself in. To understand what water will do in any circumstance, we have to consult the powers that it has, but to understand the circumstances in which it finds itself, we must look elsewhere.
As far as the generic power notion is concerned, this need not be the case. There could be powers which are such that they are had only when they find occasion to manifest. If such a power manifests, it will not be necessary to point out that the proper circumstances happened to occur, for that is in turn explained by the fact that the substance in question has the relevant power.
The relation between the presence of the power and the occurrence of the right circumstances will then be similar to that between movement and end result: just as, in the latter case, the end result will come about unless something interferes, so, in the former case, the relevant circumstances will come about unless something interferes. Thus, we could characterize this variety of power as follows: its manifestations not only explain its end result (when no interruption occurs), but also the coming about of the relevant circumstances. This can be the case if the circumstances in which the power manifests coincide with the end to which its manifestation leads when no interruption occurs. Such a power would be self-triggering, to coin a phrase. But powers of this variety may exhibit this structure also by forming a system: a substance can, for instance, have powers A–C such that its manifesting A leads to the proper circumstances for its manifesting B, which leads to the proper circumstances for its manifesting C, which in turn leads to the proper circumstances for its manifesting A again.
We should be careful, however, to distinguish this situation from a case in which something has powers A’–C’ which are such that, in the circumstances at hand, the manifestation of each merely happens to give rise to circumstances which trigger the next. For then it still holds that something may have such a trio of powers without ever running into the relevant circumstances leading to their cyclical manifestation. And that means that we would still have the fundamental ‘indifference’ towards whether or not the triggering conditions arise that is characteristic of level-0 powers. This doesn’t yield a metaphysically different variety of power. What we are envisaging now is, rather, a situation in which the powers involved are essentially caught up in the described circle: the very existence of a substance with such powers consists in its manifesting those powers in the envisaged systematically linked way. So that it is in no way optional for those power to manifest or not.—Here we already see that to this new variety of power there corresponds a variety of substance form as well. Calling powers of our new variety level-1 powers, we may call the corresponding substance forms level-1 substance forms. Wherever such a level-1 substance form is instantiated, it is, through its self-supporting system of powers, keeping itself on the scene: every movement in which such a substance engages supports own existence by enabling it to exhibit more of its powers. In that sense, such a system of powers constitutes an internally teleological system—‘internally’ teleological in the sense that the substance form in question can be considered its own end.
Having provided this brief and very abstract sketch, it will not be surprising that, in search for an example, we turn to the realm of the living. Take the system of powers that is characteristic of, e.g., an oak tree: it has the power to grow acorns, which in turn have the power to grow into oak trees (although this is of course a simplification that borders on the ridiculous), and it is obviously true that oak trees exist only when they manifest these powers as their typical life cycle prescribes (which is, we should recall, not to say that their powers’ manifestations must always reach their ends).Footnote 13
As Thompson (2008: 41) rightly remarks, a sign of the involvement of this sort of power is that it always makes sense, when studying a particular movement of the relevant kind, to ask What happens next? For level-0 substance forms and their level-0 powers such a question does not make sense: they are, as I put it earlier, indifferent as to the circumstances in which they find themselves, and so it only makes sense to ask what will happen next given certain circumstances. In the case of level-1 substance forms and their level-1 powers this question does make sense, and answering it will articulate some aspect of the system of powers in question. Think of the biologists’ descriptions, often involving stylized graphic material, of ‘the process of mitosis’ or of ‘the life cycle of the oak tree’: each phase in those descriptions answers the ‘what happens next?’ question for the previous phase (at a certain level of resolution, of course).
Another variety of power can be discerned when we focus on the role the individual substance plays in its manifestations. Consider an individual pipistrelle bat, flapping through the nightly skies, chasing a particular moth. This is a movement, the manifestation of one of the powers characteristic of the pipistrelle’s substance form: its power to hunt insects, let us say. And it is evident that this power forms a teleological system with other pipistrelle powers in the sense just described. However, this leaves out a crucial element. Consider some (unsaturated) water: any salt that is suitably brought into contact with it will be dissolved by it—the water has no preference for this or that bit of it, so to speak. Likewise, on a sunny day the oak tree’s leaves are taking up the carbon dioxide that happens to be around as they engage in photosynthesis—the leaves have no preference for this bit or that bit of it. Water dissolves salt; oak trees take in carbon dioxide: these generic power-ascribing statements explain the relevant particular movements. In the pipistrelle case, however, there is more to the explanatory story: although one can indeed say that this pipistrelle is chasing this moth because pipistrelles hunt insects, it is not a matter of course that the pipistrelle will strike whenever a moth is suitably present. First, it has to perceive the moth, and second, it has to desire it. In short: the individual pipistrelle must represent a specific target if it is to chase it. It is only through such representations that a movement like the chasing of a moth can be explained.
Now, both desire and perception are, in their turn, explained by the relevant substance form. Pipistrelles have the capacity to perceive—in particular, to detect insects; and they (generically) desire insects. Still, these powers are peculiar in that their manifestation in particular representings is required for the explanation of the sorts of movement we are trying to get into focus. Abstractly speaking, then, powers that manifest in movements of this sort, which I will call level-2 powers, differ from level-0 and level-1 powers as follows: in the level-0 and level-1 case, the individual substance does not contribute anything to what happens over and above what its substance form dictates, while level-2 powers operate only through representations of specific targets by the specific animal. As Rödl (2016: 89) writes: the animal ‘is an individual toward individuals.’ (Here we find the beginnings of a conception of the specifically animal powers of perception and desire as not ‘just another power’, but rather as constitutive of a specific form of having powers. We return to this in Sect. 3 below.)
Let us call substance forms that are characterized by systems of powers including such that depend on representation in this way level-2 substance forms. A level-2 substance form not only comprises an internally teleological system of powers: it includes powers that operate through consciousness (perception, desire). Traditionally, such powers have been called powers of self-movement: movement that originates in the individual animal, by virtue of its representations. Notice that such self-movements simply form part of the teleologically unified life cycle of animals, in the same way in which level-1 movements form part of the teleologically unified life cycle of plants.
Let us now proceed to the final variety of power. We observed that a level-2 power manifests through representations by its bearer of some particular target (e.g., this moth). The pipistrelle’s movement, its chasing a moth, is explained by noting that pipistrelles hunt for insects and that this pipistrelle desires this moth, which is present to its senses. In this level-2 articulation of the concept of power, the movement not only points towards its own end (which is what characterizes level-0 powers); it also explains why the relevant circumstances came about, as it forms part of a teleologically integrated system of powers (which is what characterizes level-1 powers); and it involves the individual substance itself, by virtue of that substance’s individual consciousness, by virtue of its representations (which is what characterizes level-2 powers). Now, remembering the schema I provided at the end of the previous section, in Table 1, this leaves out the two elements that designate something general: movement form and substance form. How could these be involved other than simply as the general forms that are instantiated in a particular movement or substance respectively? Well, there is precisely one other ‘place’ in which the general may be present: in thought.Footnote 14 Level-2 powers, we saw, depend on a consciousness of the particular: the pipistrelle’s desire has this particular moth in view. It does not include a consciousness of the general: the pipistrelle is not conscious of the movement form it is instantiating.Footnote 15 Consciousness that is capable of thought is different: it is capable of representing the very movement form it is manifesting. In philosophy, the resulting phenomenon is usually called intentional action, of which Elizabeth Anscombe (1957) famously claimed that it is something we know ‘without observation’, or, as her analysis reveals, something we practically know, the content of a practical judgment.Footnote 16
The new ingredient in level-3 powers is that the general is as such represented in the individual. So, if I make a paper boat, the explanation will not rest on a principle like ‘humans make paper boats’ (which is of dubious standing anyway). Rather, the movement will be explained by my individual representation of the movement form—that is, by my practical judgment Let’s make a paper boat. The movement is of the relevant form because that form is represented in my practical judgment—even if the movement fails to live up to that form (thus, even if my attempt at a paper boat fails miserably). Now, this is not the place to develop a full conception of practical thought or of intentional action; it is sufficient for my purposes to point out that our generic power concept admits of a variety that precisely fits intentional action, action performed by beings capable of representing the general as such—i.e., beings endowed with thought.
Still, we should point out one peculiarity in this regard. We saw that my making the paper boat is explained by my individual judgment that I should make one, not, as is the case for the other varieties of power we have surveyed, by something generic, such as ‘humans make paper boats’. Yet I claimed, at the end of the previous section, that such generic statements report, precisely, powers. So one might wonder: which power am I manifesting as I am making the paper boat? It is not the power to make paper boats. It seems that we have to say the following: we humans have the power to act intentionally, which we can now gloss as the power to instantiate movement forms by thinking them practically. Another way of saying the same thing is this: humans have the power to do what they decide to do. This power is peculiar in that it simply has no content: it does not attach the human being to a particular movement form, but rather to movement form generally. Thus, there is only one such power. In order for this power to manifest, it must first settle on one or the other movement form. That is what a practical judgment does: it determines the power to act intentionally by providing it with content. Thus, the explanatory ‘work’ that is done by the general connection between substance form and movement form on the earlier varieties of power is here done by the individual in his/her practical judgment, and therefore in the movement itself.—Note that this gives quite determinate content to the idea of autonomy, or freedom.
So far, we have seen that movements instantiating the level-3 power (now in singular) involve a peculiar relation to the movement form in question: it is represented in thought. But what about the substance form? I cannot develop the answer to this question here adequately, so an all too brief gesture as to its relation to the level-3 power will have to suffice. A level-3 substance form will be characterized by the power of thought. And that is to say that its instances will be capable of thinking their own substance form. This is, in fact, what happens in each and every practical judgment we make: in judging we always know ourselves to be judging, there is never any question as to whether it is judging that we do. And that means that in each act of our power to think we understand ourselves as beings capable of thought. There can be only one such substance form: it is that form whose instantiations are knowledge of that very form.—So much for my hopelessly inadequate gesture towards the level-3 substance form and its place with respect to the level-3 power.Footnote 17
Perhaps an illustration helps to see what this gesture gestures towards. I am writing a paper on powers: this is a manifestation of my power to act, which takes the shape that it does—that of paper-writing, as opposed to, say, paper-boat-making—not on account of external circumstances, nor on account of the fact that I am a substance of the kind that writes papers, but only on account of the fact that this is the determination that I give my generic power to act. That is why my action is my consciousness of that very action. Intentional action is “a thought that is a movement”, as Rödl says (2007, p. 19). Moreover, the content I am attempting to formulate in this paper illustrates the universality of the capacity of thought that is involved in this very activity. Thinking through the varieties of power, we realize that thought, the level-3 power, encompasses the whole range. It is not just a further rung on the ladder of powers, but rather unifies the whole ladder.
Let us sum up the four varieties of power that my inquiry yielded:
Level-0 powers, or inanimate powers, conform to the generic schema I provided in Table 1. A level-0 movement displays the peculiar explanatory relation towards its end result that is characteristic of the very idea of a power, as it gives rise to the distinction between completion and interruption, and thus gives content to the idea that movements progress.
Level-1 powers, or animate powers, manifest in movements that display an additional explanatory relation: the power itself explains why the proper circumstances for the manifestation to come about arise. Level-1 powers form internally teleological systems whose unity is the corresponding level-1 substance form.
Level-2 powers, or conscious powers, manifest in movements that display yet another explanatory dimension: their manifestation rests on the individual substance representing a suitable target (by perception and desire). Level-2 powers form internally teleological systems that operate through consciousness; their unity is the corresponding level-2 substance form.
Level-3 powers, or self-conscious powers, manifest in movements for which yet another explanatory dimension enters the picture: their manifestation rests on the individual substance representing the movement form in question. There is only one level-3 power: the power to do what one represents. It is peculiar in that it does not include any specific movement form: that is precisely what the individual’s representation provides.
Before turning to some further metaphysical reflections, let us look back at our method. We observed that what is distinctive of the generic power concept is the peculiar explanatory connection between a movement and its end. This generic power concept does not include any further peculiar explanatory relations, yet it does include ingredients that could figure in such relations (circumstances, substance, movement form, substance form). We looked at those ingredients in turn, and discovered that new varieties of power can be articulated by asking what sort of explanatory role these further ingredients may play. It is in this way that we arrived at level-1 powers, where the circumstances are drawn into the explanatory nexus; at level-2 powers, where the individual substance is drawn into the explanatory nexus; and at the level-3 power, where the movement form (and substance form) are drawn into the explanatory nexus.Footnote 18 Thus articulating the varieties of power, it has become clear that the more one draws into the explanatory nexus, the more one is confronted with increasingly complex metaphysical issues—and the likelier it is, therefore, for the resulting variety of power to be found controversial. Luckily, my aim here has simply been to introduce these varieties of power, not to defend all of them. The latter would, I take it, require showing how each variety of power of necessity gives rise to the next, and that is not what I have been doing in this paper.