Kenny on Aquinas’s Ontology of Substance and Accidents
Substance and Accidents
It is quite natural to think of
accidents as being parts or constituents of the substance to which they belong (34).
Perhaps this is because we are thinking metaphorically or simply trying to visualise a relation that is not, in fact, visualisable. How can corporeal accidents be a part of an incorporeal substance? Kenny sees the colour of a tree as an accident. The colour of a tree, however, does seem part of the tree. Despite that, I agree that a tree’s colour is not part of a tree in the ‘way in which its bark’ (34) is part of a tree. Even though colour and branches are of a different natural or even logical order, this doesn’t stop the colour, or even the causes of colour, being part of the tree. Perhaps this is all that Kenny is saying: that colour depends on minds, whereas branches do not. In that sense Kenny is right. If we look at it that way, not only is colour not part of the tree in the way that bark is, perhaps it is not part of the tree at all – it is not even an accident. It is not an accident if accidents must not depend on minds for their existence. However, all we have here is the empiricist distinction between primary and secondary qualities, not one between substance and accidents.
Despite all that, Kenny’s other example of an accident is not of the same logical order as colour (mind-dependent or otherwise). He calls ‘Socrates’ being taller than Simmias’ (34) an example of an accident. Of course this accident is not literally a part of Socrates in the way that his snub nose is. However, unlike colour, the accident of being taller than something is a relation or extrinsic property, unlike the accident of colour, which is intrinsic and non-relational. Or, it is intrinsic if we are in fact talking about the causes of colour experiences in a tree. If we are talking about experience of colour, however, it would also be seen as a relational property: the colour of a tree is related to the existence of minds.
If substance and accidents did enter
into some sort of composition with each other (34)
this would indeed be hard to explain, just as the relation of mind and world, two different substances, is hard to explain. All this depends, of course, on our prior acceptance of the metaphysical fact that accidents and substances are in fact of a different ontological order. In fact it depends on our acceptance of the substance/accident duality in the first place.
Of course we will see
accidents as a sort of outer skin or veneer (35)
but only if we also accept the existence of substances in the first place. There can only be an ‘outer skin’ if there is a substance. We can see the bark of a tree or the skin of an apple as an outer skin, but the ‘kernel or marrow’ (35) in that case would be equally material, unlike the case of substances. In that sense, of course it is wrong to think of accidents as making up the ‘outer skin’ of substances because substances are not like the interiors of trees or the flesh of an apple. No, substances, if they are genuinely immaterial substances, could not be seen as the ‘kernel or marrow’ of anything. Such spatial terms would simply not make sense when talking about immaterial substances and accidents that may well be material.
However, traditionally it was accidents that were seen as abstract, and substances were seen as concrete. Here again we would have the problem of explaining the precise relation between abstract and concrete entities.
In the case of ‘abstract’ accidents and ‘concrete’ substances, what do we mean by these adjectives? It is tempting to define ‘concrete’ as that which is ‘tangible’ and ‘abstract’ things as ‘intangible’. However, Kenny stresses that this neat division is not quite so simple. For example, according to Kenny air is a substance, but air is ‘not in any simple sense tangible’ (35). And as Kenny says, certain ‘abstract’ accidents are ‘tangible’, such as ‘the roughness of a piece of sandpaper’ (35). Again, all this depends on a prior acceptance of the ontological category of ‘substance’. And if we don’t accept this category, then the substance/accident distinction will not be accepted either. And if this is the case, then all the problems Kenny has so far highlighted will also vanish. Of course other problems will arise from other ontological categories or schemes that we adopt.
Kenny seems to be arguing that substances are indeed ‘perceptible’, but they only are so by ‘perceiving their accidents’ (35). In perceiving a substance’s accidents, we, in a sense, also perceive the substance. This must mean that although the substance is distinguishable from its accidents, it somehow ‘shows itself’ in its collection of accidents. In that sense, even though a substance is not simply a ‘bundle’ of accidents, nevertheless we still ‘perceive’ the substance ‘by perceiving their accidents’ (35). This seems strange at first. Kenny says that we perceive substances, but he also says that this still means
that tangibility is not the distinguishing characteristic of substance (35).
We must conclude, therefore, that although substances can be ‘perceived’ when we perceive ‘their accidents’ (35), substances on their own would not be perceptible or ‘tangible’. Of course this would depend on whether substances could exist at all without their accidents. I think that Aristotle, and therefore Aquinas, both denied the possibility of their separate existence. This would of course be very similar to Aristotle’s claim that ‘universals’ only exist within the ‘particulars’ that instantiate them.
Kenny then explains why we can ‘see’ substances. The fact is that we can perceive substances only by the addition of something else other than the sense of sight – ‘intellect’. When we see a substance, we ‘see’ it because we see something ‘of a certain kind’ (35). Sense-perception alone would not tell us that a thing was ‘of a certain kind’. Therefore sight alone could not perceive a particular substance as a substance. In that case, it is perhaps wrong to say that we ‘see’ or ‘perceive’ a substance at all if we bear in mind that there must always be something over and above the mere sight of a substance. This means that sense-perception is indeed necessary, but it is not sufficient for a perception of a substance. Despite all that, Kenny still argues that ‘substances may be perceived’ (35). Again, if the ‘perception’ of a substance necessarily depends on the intellect, then perhaps we still do not strictly ‘see’ a substance. What we do see are the accidents, or the collection of accidents, that tell us that a particular thing or substance is present. What we ‘see’ is not actually the substance, but the accidents that betray the existence of a substance. A particular collection or set of accidents tell us that a particular substance is present, but we still don’t literally ‘see’ the substance.
Kenny gives an example of this. We can indeed see that sulphuric acid is a substance. However, we only see sulphuric acid because of our
intelligent use of hypothesis and experiment and information that we know that the stuff we see is sulphuric acid (35).
If we didn’t have these hypotheses in mind, or know of the experiments needed to show us what sulphuric acid is, then we would not ‘see’ sulphuric acid. We would see the same set of accidents, and perceive the same kind of sensory items, as the chemist, but we would not see these things as sulphuric acid. In that sense, we would not see the substance at all. Even if we were a chemist, we would still not literally see sulphuric acid, if such non-accidental and non-sensory things such as experiments and hypotheses are needed to see sulphuric acid as sulphuric acid rather than as an unknown something that, however, still seems to be a set of accidents of some kind.
Kenny seems to be putting the Aristotelian position, adopted by Aquinas, on substances. Indeed just as Aristotle talked about ‘particulars’ instantiating ‘universals’, and that universals do not exist in separation from particulars, so here Kenny is treating substance as Aristotle treated particulars. Kenny says that
substances are entities with a history which enter into causal relations with each other (35).
Universals can only do so when they are instantiated in particulars with non-abstract and non-universal properties. Universals in the Platonic sense do not have a ‘history’ or ‘enter into causal relations’, Aristotle might have argued. However, we are supposed to be talking about substances here.
Instead take wisdom as a substance. It is only a substance that must be instantiated in a particular. In other words
the wisdom of Socrates grew through time, had effects in his own life and the lives of others (36).
Here again, just as substance can only be ‘seen’ when they are seen ‘with their’ accidents, so substances can only ‘enter into causal relations’ when in conjunction with their concrete particulars, in Kenny’s example, an individual such as Socrates.
This means that Kenny’s wisdom-as-substance cannot be seen as Plato’s Wisdom with a capital ‘W’. Plato’s Wisdom could not ‘enter into causal relations’, as Aristotle argued. It could only do so if the universal Wisdom were instantiated in causal particulars which would enable them to ‘enter into causal relations’ with other universals that were also instantiated by particulars. And Kenny too doesn’t think that wisdom-as-substance exists ‘beyond space and time’ (36). But, instead, only exists within concrete and causal individuals that are also sets of particular accidents. Substances, therefore, are taken in the way that Aristotle took universals. In that sense, they are not Platonic entities after all.
On the other hand, perhaps it was the case that accidents were seen by both Plato and Aristotle, or by Platonists and Aristotelians, as ‘timeless and insulated from the hurly-burly of the world’ (35). In that case it would be accidents, rather than substances, that are seen as Platonic entities. Accidents too, like universals, can only exist as aspects of particulars or aspects of substances. In that case, accidents, rather than substances, seem to be like universals. Only universals in the Aristotelian rather than Platonic sense, as only existing as aspects of particular substances. However, if accidents only existed as aspects of substances, that still wouldn’t automatically mean that accidents were necessarily ‘timeless and insulated from the hurly-burly of the world’ (35). Accidents may necessarily depend on Kenny’s substances, but still not be ‘timeless’ or even ‘abstract’ and non-spatiotemporal. There is no problem with accidents in that case. After all windows could only exist if they were inside window-frames; but windows are not ‘timeless’ or abstract because of that fact. Of course there is a difference. The accident ‘red’ is not deemed to be material in the same way as a window. And the accident being taller than… is certainly not material. They couldn’t exist without their substances and are also non-material. However, the accident of a big nose could exist without any substance. If the nose were chopped off and landed on the floor it would still be material and temporal. It would still be a nose. However, if a nose were disconnected from its substance or subject, then perhaps it could no longer be seen as an accident. It would, instead, be another substance with its own accidents in distinction to the substance of a man who had lost the accident that was his nose.
Like Platonic universals, if accidents were truly ‘timeless’, and then perhaps also non-spatiotemporal, how could they have any kind of relation, let alone a causal one, with substances that are deemed by Kenny to ‘enter into causal relations’? In that case, all the traditional problems faced by universals are now faced by accidents if seen as ‘timeless’, etc.
Kenny again puts the Aristotelian, and therefore Aquinian, position on accidents. There is an Aristotelian phrase that clearly expresses Aristotle’s position:
For an accident to be is to be of (36)
This clearly states that accidents do not even exist if they are not parts of substances, just as universals, according to Aristotle, do not exist unless within particulars. In other words, accidents are always accidents ‘of’ something that is not an accident. They must belong to something else, in Aquinas’s case, to substances. There is another Aristotelian phrase that puts this position a little differently:
An accident is not what is but is of what is.
This rather clumsy phrase states that accidents are ‘not what is’. Taken only in the sense of that clause, accidents simply do not exist. However, the last clause says that accidents are ‘of what is’. Even if they only exist if they are ‘of what is’, then they still must exist. What the whole phrase is saying is that an accident cannot exist unless it is ‘of’ something that does exist. In that case, accidents are actually brought into existence only when they are ‘of’ something that also exists.
Clearly if we accept accidents as taken by Aquinas, then the above is evidently the case. Accidents must be ‘of’ something. If a shape, and a smile, and a weight, are accidents, then these things must be ‘of’ something. You cannot have a shape, a smile and a weight existing on their own, or even together. A building has a shape. A person has a smile. And a rock has a weight. These three accidents may indeed belong to the same thing. For example, John Smith might be smiling; he might have a particular shape; and he must weigh a particular weight. All these things that have accidents, a building, a person, and a rock, must therefore be substances in Aquinas’s ontology.
Kenny talks about our talk of accidents. When we talk about accidents
we are really talking of the modifications and changes of substances (36).
Because accidents cannot exist without substances, then when we talk about them we are in effect talking about substances. This must also mean that nothing really happens to accidents even when they are the accidents of substances. Things happen to the substances, not to the accidents. This also means that accidents cannot change; only substances can change. If substances are only bundles of accidents, then things must happen to accidents and accidents must change.
Kenny is more precise about what we talk of when we talk of accidents. We are talking of the ‘modifications and changes of substances’ (36). From that Kenny makes it clear that it is only substances that necessarily remain over time, not their accidents. Again, Kenny stresses the distinction between substance and accident by saying that accidents are ‘modifications’ of substances. That is an interesting word to use of accidents. They ‘modify’ substances. This means that accidents ‘change’ substances, as when a yellow ball turns black, or a person begins to smile. However, I said earlier that substance must remain over time. Then how can accidents be ‘modifications and changes’ of substances? If substances can be modified or changed by accidents, then in what sense do they remain the same over time? It could be the case that substances are both things with accidents and also things without accidents. Does that make sense? It could do if there were two aspects of a substance. A part that is changed and modified by accidents. And a part that isn’t changed and modified. In that case, we would have an essential part of a substance, and a contingent part. Would that also mean that if we only know a substance through its accidents, as stated earlier, then a substance must have essential and accidental accidents. The essential accidents remain over the entire existence of the substance, whereas accidental accidents come and go. However, if we distinguish essential accidents of a substance, and accidental accidents of the same substance, then how can any accident be ‘accidental’ and how can any accident be ‘essential’? If an accident is ‘essential’, then it can’t actually be a genuine accident. And it is tautological to talk of ‘accidental accidents’. This must mean that the part of a substance that doesn’t rely on accidents must be known in a way that doesn’t depend on any accidents – it has none. Kenny has said earlier that substances are known and seen through their accidents, so there cannot be a part of a substance that has no accidents. And if all the substance depends on its accidents in the sense of our knowing and perceiving it, then how can a substance remain throughout all the changes and modifications of the accidents? The conclusion must be that although Aquinas thought that substances are known and perceived because of their accidents, they are, nevertheless, not accidents or particular sets of accidents. If anything of the substance is essential and unchanging, it can’t be any of its accidents. What is essential and unchanging must be something of a different kind than accidents. What is the essential and unchanging part of a substance?
A’s F-ness and Form and Matter
A’s F-ness must not be a reference to a predicate or an accident of A. A’s F-ness cannot be its yellowness because A cannot be a yellow unless A’s F-ness simply means that ‘A is yellow’. A’s yellowness is an accident or property of A, but it is not what A is or the kind that A is. It would be simpler if the F-ness of A were something like politicianhood or manhood or even Blairhood. In that case A’s being F would simply be ‘A’s being a politician’, or ‘A’s being a man’, or ‘A’s being Blair’.
Next Kenny talks about ‘the coming into being of A’s F-ness’ (36). This means
nothing other than A’s becoming F (36).
This seems, at first, stronger than ‘A’s being F’. A must become something, or something else, when it becomes F. Here again we can talk about accidents, in that Blair’s yellowness can ‘come into being’. It seems, however, that the
coming into being of A’s F-ness is nothing other than A’s becoming F’ (36)
is a reference to A not changing an accident, but A becoming something else. Instead of A’s F-ness becoming A’s G-ness, say Blair’s truthfulness becoming Blair’s dishonesty, we have A becoming F. For example, a politicians becoming a priest. In that sense, the same substance can change kinds. However, if A’s being a politician can become A’s being a priest, then both being a politician and being a priest must be accidents or accidental properties. What if A is a tree and F is a cat? In that case, a tree’s cathood cannot ‘come into being’. And a tree’s cathood cannot be ‘nothing other than’ the tree’s becoming a cat. For a start, a tree cannot be catty, which would be a Rylian ‘category mistake’. And a tree cannot become a cat because it couldn’t be a tree that so becomes.
It seems to follow that the A and the F-ness above must not refer to Aquinas’s substances. This means that a substance cannot be another substance (‘A’s being F’). And one substance cannot become another substance (‘A’s becoming F’). Kenny’s use of ‘A’ and ‘F-ness’ above must be his way of showing the fundamental difference between accidents and substances. The A and F-ness above must refer to accidents, even if the accidents are of a different kind. In ‘A’s being ‘F’, the ‘F’ could be yellow, but the ‘A’ could be a politician. The politician is yellow. Clearly the accident ‘being a politician’ is a different kind of accident than yellow. One is an artificial kind accident, and the other is an abstract universal property. And with ‘A’s becoming F’ we must also distinguish the kind of accidents referred to. For example, ‘a politician becoming a priest’ is a case of two artificial kind accidents, whereas before we had the artificial kind accident politician and the abstract universal accident yellow or being yellow.
None of the references so far of ‘A’ and ‘F-ness’ have been substances – they were all kinds of accident. However, what if ‘A’ referred to Tony Blair? In that case, Blair can indeed be yellow (‘A’s being F’). What about Blair becoming a priest (‘A’s becoming F’)? That seems fine. However, what if ‘F’ referred to another individualised substance (say, John Smith), rather than the artificial kind accident being apolitician? In that case, Blair could not become John Smith. It could not be Blair that became John Smith.
The conclusion must be that one substance cannot change into another substance, though a substance can change its accidents. Blair can become yellow or become a priest, but he could not become John Smith, just as a fish couldn’t become a chair or a building or a hat. It follows that substances are fundamentally different to accidents. And they are so because they can be taken as essential or as essences, and also unchanging, whereas accidents are contingent and, well, accidental as well as being capable of coming and going, at least when they are ‘of’ a particular substance. However, accidents if taken as separable from substances, as they have been, can also be seen as unchanging and timeless. However, if they are taken like that, then surely accidents are essential too as well as unchanging. Or, alternatively, perhaps these possibly timeless and unchanging accidents have their own essences. And we also could say that the essences of timeless and unchanging accidents do not depend on accidents in any sense. Or if they depend on their own accidents, perhaps an accident’s essence is made up of essential accidents rather than contingent accidents of an otherwise timeless and unchanging accident or set of accidents. It is clear here how speculative ontology, if all ontology isn’t by definition speculative, can go in so many directions and loose itself up its own arse.
Despite everything that has been said so far, Kenny now says that
Aquinas is quite prepared to contemplate the possibility of accidents existing without inhering in any substance (36).
This is where, rather predictably, Aquinas’s religious beliefs enter the story and in a sense make his previous arguments about accidents senseless. In fact he even makes his position on accidents self-contradictory. However, his view on accidents when infected by his religious beliefs must bring into the world of ontology the ‘miraculous exercise of divine omnipotence’ (36). To give an example of this take his position on the sacrament of the Eucharist. He now believes that after
the consecration of the bread and wine, the accidents of bread and wine, he believed, remained in existence after the bread and wine had become the body and blood of Christ (36).
Aquinas admits that this is ‘miraculous’. However, did he mean that the accidents of the consecrated bread and wine ‘remained in existence’ as aspects of the body and blood of Christ, or that their accidents remained in existence outside any substance? In the first case, the accidents of bread and wine must become accidents of the body and blood of Christ. This doesn’t seem to make sense. How can the accidents of bread become accidents of Christ’s body? And how accidents of wine become accidents of Christ’s blood? It may be the case that blood and wine, and also bread and Christ’s body, share certain accidents, but can they share the accidents that distinctly belong to these different things?
Alternatively, the new belief that accidents can ‘remain in existence’ might have meant that such accidents exist outside all substances.Aquinas, as an Aristotelian, had already rejected this possibility. However, in order to square his ontology with his religious beliefs, he seems to believe two contradictory things about accidents. Or, more literally, he believes that accidents are a certain way when under normal ontological conditions, but that they change their nature when affected by ‘divine omnipotence’, in the form of a miracle. Clearly in that case he is not offering us a philosophical argument for the nature of accidents under miraculous conditions. He couldn’t have done so because such a position would have contradicted his prior philosophical position on accidents. Instead he must have offered a view of accidents that must be accepted on faith. If faith in miracles is now the issue, then why should accidents and substances even exist as distinct ontological categories in such a miraculous situation? If something miraculous can happen to accidents, then something miraculous could happen to substances too. Indeed under such miraculous acts or situations, perhaps there would no longer be accidents and substances because they simply don’t exist in such miraculous situations. In other words, why should ‘divine omnipotence’ simply stop at giving accidents a new nature? Why doesn’t the Divinity subvert or change Aquinas’s, or anyone else’s, entire ontological scheme? The point is that anything goes, ontologically, if we have faith in ‘divine omnipotence’ and miracles. One could now ask why Aquinas bothered at all with his acute analyses of being, that is substances and accidents, if he in the end simply subverts and even contradicts his philosophical positions by bringing on board faith, miracles and ‘divine intelligence’? If faith allows Aquinas’s particular subversions and contradictions vis-à-vis the nature of accidents, then another faith, or even Aquinas’s own, could subvert or contradict any well-argued philosophical position.
You could imagine the Cheshire Cat’s grin without the cat; it has actually been drawn. Perhaps it could not exist without the cat. However, because the cat and its smile are purely fictional, then even the fictitious smile can be imagined. It depends on what Kenny means by ‘idea’. However, I think that Kenny’s parallel between the enduring smell or taste of onions with the enduring and substance-less accidents of the Eucharist is not at all accurate. If the smell or taste of onions hangs around after the onions have been eaten, it is because both that smell and taste depend on physical things: the onions’ remaining molecules that ‘hang around’ in the air after the onions have been eaten. In that case, there is something physical left of the onions, even if the onions themselves are no longer existent. There would be no remaining smell or taste if it weren’t for physical and scientifically detectable molecules in the air. This is not the case with the Eucharist. In this case the accidents of bread and wine are supposed to remain after the bread and wine are turned into the body and blood of Christ. Even if the bread and wine were now the body and blood of Christ, would it make sense to say that their accidents were still in the body and blood of Christ? Would the sweetness of the wine still be in the blood of Christ? Would the soft texture or taste of the bread still be in the body of Christ? Perhaps if Aquinas meant that the accidents of bread and wine remain but were not in the body and blood of Christ, then things would be different. In that case, smell and taste of the bread and wine, like the onions, could still remain. They would not do so indefinitely. These remaining accidents would not be ‘timeless’ or ‘abstract’, they would be scientifically detectable, as is the smell and taste of the defunct onions. ‘Timeless’ and substance-free accidents were not seen as transitory and detectable when Aquinas considered the case of the Eucharist. The alternative would be that the remaining substance-less accidents of the bread and wine are ‘timeless’ and undetectable. In that case, they would not be like the remaining accidents of the onions, which are temporary and detectable scientifically.
The same kind of arguments are also applicable to Kenny’s example of a boot and the shape of the boot in the snow. Again, even if the boot is defunct, the shape of the boot in the snow is still a physical fact. The shape of the boot is still physical. Indeed because it is physical or material, this ‘accident’ of the boot could be seen as a new substance, if we use Aquinas’s own arguments. That means that if the shape is no longer a part of a boot, then according to Aquinas it can no longer be seen as an accident of the boot. Aquinas believed, along with Aristotle, that accidents must belong to substances, but the shape of the boot is no longer part of the defunct boot. In that case, perhaps the snow-shape is a new substance with its own accidents. The accidents of the boot-shape in the snow could be its whiteness, its boot-shape itself, its soft texture and so on. The boot-shape will actually have accidents that the boot itself didn’t have. The boot, for instance, was not white, and it is silly to say that a boot has the accident of a boot-shape, and it had a hard texture rather than the soft texture of the snow. This would give the Aquinian ontologist more of a reason to think the boot-shape is a substance unto itself. Not only does it have its own accidents, but some of the accidents are not the same as were the boot’s own accidents.
Kenny then talks about accidents that have never belonged to substances. For example, the colours of the rainbow and the blueness of the sky. If these accidents genuinely don’t belong to substances, then by Aquinas’s own onto-logic, we have no right to call them ‘accidents’ at all. They would be accidents if, say, the blueness belonged to a ball. The term ‘accident’ is part of a binary distinction: accidents and substances must always come together, just as there could be no book without words or good without bad.
Is it is true that the colours of a rainbow and the blueness of the sky belong to no substances? For a start, we can say that they belong to the rainbow and the sky. Someone could respond to this by saying that a rainbow is nothing but its colours and the sky is nothing else but its blueness (or other accidents). This is not so. We know that colours are caused by physical phenomena, perhaps molecular configurations of a particular kind which cause light-waves of a certain kind. And then, of course, the sensation of colours depends on minds, if the colours themselves are not actually in the sky or rainbow. The colours must still belong to something in the sense that they belong to the physical phenomena that cause them. Of course such things are not perceptible by sight or touch, but they would still be scientifically detectable. It may follow, then, that the substances of the rainbow colours and the sky’s blueness are both formal and material in the Aquinian sense, but imperceptible in the sense that many other substances are imperceptible. However, it is also the case that Aquinas argued that the formal substances would also somehow be in the colours themselves.
It appears, then, that Kenny has fallen into the trap of empiricists or positivists who reject substances because they cannot be observed. He too seems to deny the blueness of the sky and the colours of the rainbow their own substances. Despite that, if my substances are physical, then perhaps Kenny would not think them genuine substances. Again, all this comes back to having a precise definition of the word ‘substance’ or the thing, substance.
According to Kenny
a change of shape is an accidental change, not a substantial change (39).
This means that when a thin man becomes fat, his fatness becomes a new accident. In that case, an accident changes, but the substance, the man, remains the same substance. Can we say that the shape itself ‘changes’? Does the accident thinness become the accident fatness, or does the substance, the man, simply acquire a new accident and therefore it is not the accident that changes, but the substance. In that case, the accident thinness simply ceases to be, rather than ‘changes’.
Kenny stresses the distinction between the change of a substance and the changes of accidents. He brings in the important word ‘kind’ or phrase ‘kind of thing’. Substantial change requires a change in the kind of substance. Accidental change only requires a change in accidents. If a man becomes a book, then that change is a substantial change because the words ‘man’ and ‘book’ are kind-terms. However, if the book’s pages turned brown with age, then this would be an accidental change because ‘brown’ is not a kind-term, but ‘book’ is. The accident brown is a property, not a kind.
Then Kenny makes a distinction between the predicates of the substance and the predicates that express the accidents. If the substance does not change, it is because its essential predicates do not change. The predicates of the substance’s accidents, on the other hand, do change. It must be the case, therefore, that a substance has its own predicates because Kenny says ‘the predicates of the category of substance’ (39). Does this mean that a substance must also have accidents? What kind of predicates does a substance actually have? Are they essential predicates or accidents rather than contingent ones? Perhaps the predicates that belong to, or express, a substance cannot or are not accidents, but predicates of a different kind.
Kenny gives an example of substantial change in the case of the death and decomposition of a dog’s body. In this case it is not the case of one substance, the dog, changing into another substance, but one substance turning into many substances. What are these ‘independent’ (39) substances in the case of the dog’s decomposition? Kenny argues that these independent substances are
the various natural elements into which the body decomposes (39).
At first it seems odd to think of ‘various natural elements’ as substances if we have so far thought of substances as things like persons, apples, cats, and so on. Why are natural elements substances? It must mean that they are self-subsistent in some kind of way and also, on the Aquinian picture, they too must have their own accidents alongside ‘predicates’ that do not change.
The dog’s decomposition example is one of ‘one-many’ (39) substantial change. The dog’s body substance changed into ‘many’ other substances – into many ‘various natural elements’. There is also the case of the ‘many-one’ substantial change. In this case, Kenny gives us the example of ‘eating and digesting a varied meal’ (39), the many substances of the meal, say, carrots, peas, etc., are eaten and digested. And when fully digested turned into a single substance. Perhaps that single substance, although Kenny does not say, is the waste that we excrete. Waste, therefore, must have its own accidents, which, of course, it does.
In substantial change, the substance, form or kind changes, and so too do the accidents, but the matter remains the same. When a man, substance A, turns into a priest, kind G, then the priest and politician share
some stuff which is the same parcel of stuff throughout the change (39).
In that sense, that stuff was F-ish when it belonged to a politician, and then G-ish when the politician became a priest.
We have, therefore, both substances and kinds. Substances change when they change into a different kind. When substances change their accidents, on the other hand, there is no change in kind and therefore no change in substance. It must mean, therefore, that kinds are not determined by the accidents that belong to them. Surely there are predicates or properties applicable to, for example, politicians qua politicians and priests qua priests, otherwise we couldn’t identify them as the kind that they are. We can see that Kenny’s use of the word ‘predicates’ means that such things do not express or refer to accidents, but, instead, to properties that are essential to kinds and substances.
Despite Aquinas’s use of the medieval theory of the elements, he believed that air can turn into fire. In this case, one substance or kind turns into another substance or kind. This means that the ‘form’ of fire ‘begins to exist afresh’ (39) when it comes into being. However, the ‘matter’ of the air is still part of the new substance, fire. The same is the case with Aristotle’s substance food turning into a human being that ‘begins to exist in the matter of the food’ (39). Here again, the food’s matter is passed on to form the matter of a human being, which, in turn, must have been informed with the ‘form’ of a human being, not the form of food. It could be doubted, however, that food could be deemed a substance, especially if it is deemed to be a collective word. We should bear in mind Kenny’s previous example of the ‘many-one’ of the ‘many’ food or ‘meal’ turning into the ‘one’ of that food’s digested or excreted state. In that case, Aquinas’s substances (e.g., peas, carrots, meat, etc.). This would therefore be an example of a ‘many-one’ relation between food and the new human being.
We must stress that in substantial change one type or kind (say, air or food) turns into another type or kind (say, fire or a human being).
