Locke on Living Things
Ayers (Michael R.)
Source: Ayers - Locke (Vol. 2 - Ontology), 1991, Chapter 19, pp. 216-228
Paper - Abstract

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Introductory Note

  1. Page 225 of this paper was cited in "Olson (Eric) - What Are We? Animals" (Section 2.21) to the effect that Ayers – contra Olson – counts dead elements – hair, hooves etc. – as part of a living organism.
  2. However, this article includes lots of interesting stances and arguments on the general topic of the persistence of organisms, so I’ve scanned in the latter half, which contains Ayers’ views – as distinct from Locke’s – so that I can comment on them in detail.
  3. I’ve omitted the first half (pp. 216 – 222) as I’ve no interest in becoming a ‘Locke scholar’.
  4. I’ve decided to keep my comments – restricted to footnotes – fairly brief. Much more could doubtless be said.

Full Text (pp. 223-228 only, end-notes omitted)
  1. (p. 223) ... a reminder that we need to know what kind of unity is possessed by the individual (whether natural or constructed) that is the subject of any question of identity.
  2. The probability is that Locke, like many twentieth-century philosophers, was never remotely clear on this rather fundamental issue. There is undeniably a repeated suggestion that the criteria of identity for both the man and the person can simply be drawn out of our ideas of man and person, as a part of the meaning which we arbitrarily choose to ascribe to the words. In the case of ‘person’ there is also the insistence that the use of that ‘Forensick Term’ is inspired by our interest in pleasure and pain, reward and punishment. There is even an explicit analogy drawn with mixed modes in this respect. On the other hand, the argument which finds the criterion of identity of a plant in its unitary, unifying life does not seem to take the form of a simple appeal to the idea of an oak ‘in most people’s sense’, but rather to be an appeal to mechanist theory2, i.e. to the mechanist alternative to the unifying Aristotelian form or soul. It is true that the boundary and unity supplied by a single mechanical life-system, in which all the parts co-operate ‘to a certain end’ like the working parts of a watch, may be less absolute than the boundary and unity purportedly supplied by a specific form. The present point is that it is nevertheless a natural boundary and unity, and that Locke’s explanation of it is based on a mechanistic model of what a living thing or body is, rather than an analysis of the ordinary concept of a plant or an animal. Without that model, which was surely not the property of every seventeenth-century peasant who could identify and count plants and animals, it would be quite mysterious why life should be proposed as their independent principle of individuation3 rather than simple cohesion or, for that matter (if nominalism is thought an attractive option), some such attribute as heat or vibration. For these attributes, as much as life, can pervade for a time the whole or a part of a discrete physical object. Certainly the view of a half-dead tree which would see only the living part as constituting the biological individual is not the view of the ordinary person, as embodied in ordinary language. The unnourished, non-growing heartwood, or even an attached dead leaf, would naturally and normally be thought a part of a living tree. Locke did not consider such examples. If he had, it might have been clearer whether he saw himself as appealing to everyday ideas and language4 or, on the other hand, to mechanist theory as to what biological unity must be.
  3. It is not necessary, however, to determine whether Locke’s account of the identity of substances5 is in the end ‘nominalist’ (or ‘conceptualist’) or ‘realist’ in order to find an argument against the notion that three distinct material objects6, distinguished by their life-histories and each (p. 224) unified by a distinct principle of identity, might occupy the same place, and be composed of the same matter, at the same time. The issue of personal identity is peculiar, and the argument will be restricted for the time being to the possibility of a distinction between the physically coherent, discrete body which can outlast the change from life to death7, and the living-thing (e.g. man) which allegedly cannot do so. What must be said about this distinction follows from all that was proposed in Part I, above, in the argument which picked a way between Aristotle and Locke on the topic of natural classification and endeavoured to get to the root of the difference between substance and mode.
  4. To apply a predicate8 like ‘horse’ or ‘man’ to an object is not to pick out something other than the independently identifiable, materially concrete, discrete thing before one, but is to classify that thing itself: to attribute to it membership of a natural class in virtue of its origin and structure. The thing’s life is both a consequence or inseparable function of its origin and the continuing explanation of its structure and parts at any moment of its existence. Life is essential to the thing in so far as it is inconceivable that it (this thing) should have come into existence as a non-living thing. The thing exists, and exists as it does, with the structure and parts that it has, because it is alive9. In that sense we can say that life is its natural principle of existence and unity10. But that is not to say that when it dies the thing itself will cease to exist: merely that an explanation of the existence and structure of the thing will then refer to a life that is over. The continued unity of a plant or animal after death obviously cannot be attributed to its continuing life, but even before death the conditions of its physical coherence at any one time were laid down by previous, rather than current, life-processes. An animal or plant is not unified or given physical definition by a mysterious, instantly active life-force. There is no such force11 as so constitutes the unity of the thing that, when the force Is 'switched off, the unity instantly and necessarily evaporates. The sense in which life is the ‘principle of unity’ of a living thing is one which presupposes that ‘unity’ can be understood in other terms12. These terms are supplied by our inescapable recognition of material coherence and discreteness13. That is why the living thing can quite straightforwardly outlast its life14. Life is to that extent an ‘accident15’ of the thing. It follows that we cannot distinguish between the principle of individuation of the oak or horse and that of some essentially united mass of matter which composes it16. They are therefore identical.
  5. Life, then, cannot constitute the unity of an individual, but deserves to be called a ‘principle of material unity’ just because unity is open to explanation in each case in more primitive terms. Nevertheless, because life is a principle of unity, an object’s being a living thing is not merely irrelevant to questions about its boundaries or identity. A (p. 225) stone which is enclosed by the growing trunk is not a part of the tree17, even if it is as firmly embedded in the tree as is the heartwood. The dead heartwood has, as well as coherence, a historic causal connection with the life of the still growing part of the tree a relation similar to18 the historic connection which a dead tree has with its earlier life. In normal circumstances rather less of an animal than of a tree is at any time excluded from the ‘common life’ (hair, hooves and so forth). These again are a part of the whole animal19 as an unassimilated foreign body20 is not. In another sort of case, what was initially a foreign body becomes a part of the individual by coming to participate in the common life, as in grafting or transplant surgery21. A plastic hip-joint, however, like a false tooth, can never become part22 of the individual. The relevance of life to identity also appears in certain borderline cases of identity at a time. If two (or arguably two) individuals seem not to be fully discrete, as in the case of joined twins, it is relevant (although not necessary) to our distinguishing them that each twin should have the parts necessary for a separate life23, and so in a sense already lives independently of the other.
  6. A similar consideration applies to certain trite questions of continuity. If an inanimate object, such as a block of marble, splits into two quantitatively equal parts, there is no reason to identify either of the resultant blocks with the original, and thus no reason to hold that the original individual survives24 as one. The same25 may apply to a living thing such as a herbaceous plant divided at the root. But a living thing can also be divided in such a way that only one part contains what is essential to life. The smaller part of a divided amoeba26, if it contains the nucleus, may continue to live. It is then identifiable as the individual of which the larger, but dead and separated mass of protoplasm was formerly a part. The smaller part contains, so to speak, the principle of the thing’s existence and survival27.
  7. These examples may go some way towards excusing the doctrine that life supplies a principle or criterion of individuation which is wholly independent of the coarse criterion of material coherence and discreteness, but they do not justify it28. On the contrary, the point that the causal principle of an animal’s or plant’s unity has this kind of relevance to its continuing identity presupposes that animals and plants are, at least normally, coherent and discrete, i.e. that they are characteristically physically or materially unitary objects. Even in the case of animals joined at birth, a judgement that they are distinct individuals is related to a belief in their potentiality for literally separate existence29. Such twins, it is true, might be thought to invite the argument that it is the sortal concept, or a ‘criterion of identity’ arbitrarily associated with the sortal term30, which determines the line between individuals. For it is characteristically because of our knowledge of their relationship with (p. 226) other members of a species that we can be sure in such a case that we are dealing with two natural individuals rather than one. Yet that is only because our knowledge of the physical nature of what is before us is normally grounded on knowledge of such a relationship. It is not because in this case (still less in all cases) the boundary round the individual member of a species is drawn by our sortal concept31 rather than by nature. If it does prove helpful to descend from the level of the question whether there are two natural individuals here or one, to that of asking whether there are two members of the species man, the reason is not that there is a ‘criterion of identity’ or counting associated with the word ‘man’ which is independent of material discreteness or natural boundaries. The reason is that ‘man’ is the general name bestowed on certain materially unitary objects to which what is before us (which may certainly belong to the species man even when questionably dual) is related by origin and structure. It may be helpful to know32 with what natural individuals it is most appropriate to compare what is before us. Attached or conjoined natural individuals may be odd ones, but by the same token (indeed, therefore) they will be odd men and animals too.
  8. It is a common but mistaken thought that reference to an appropriate sortal concept can always supply, or ought always to supply, a definite answer, one way or the other ‘with no nonsense’, to a question whether there is one individual or two. It is mistaken because such a question, when asked about substantial things, concerns a natural boundary. Consequently what our understanding of such natural boundaries cannot do, the notion of a man, horse or plant cannot do either. To recognize that borderline cases of identity should by no means be attributed to regrettably sloppy sortals33, we need only reflect on the continuum ranging from, say, twin animals joined by a small piece of cartilage to the case of a deformed animal with eight legs, or with two heads. (Even more impressive arguments can be drawn from the world of plants.) Abnormal births can thus seem to illustrate two quite different types of borderline corresponding to the orthodox distinction34 referred to above between the criterion of application for a sortal predicate and the criterion of identity associated with it. We have noticed Locke’s own interest in problems about the classification of monsters, problems which, in accordance with his conflation of clarity with precision, he thought could always be settled definitely by reference to a ‘clear and distinct’ nominal essence. He believed that when we cannot be definite about some case, it is entirely due to our failure properly to determine which criterion of application we wish to associate with the sortal term - our failure to give it a clear meaning. Such a programme of tidying up our judgements35 by tidying up our concepts is based on assumptions generally inappropriate to predicates having (p. 227) a role in natural language. But it peculiarly misconceives biological classification36, which essentially depends upon the existence of underlying natural affinities, if not natural classes. It is a very similar mistake to hold that with every predicate is associated a criterion of identity which will be sharp enough, or else should be made sharp enough by ‘decision’, to settle every problem over how many members of the species we have, or whether we have the same individual again. For the programme of making our ‘concepts’ more ‘precise’ in this direction is likewise out of tune with the whole enterprise of objective natural classification. Biological taxonomy in general starts from the assumption that there are naturally distinct individuals, to be placed as far as possible in their natural classes. With respect to either sort of natural boundaries, if they are sometimes less than perfectly definite, it will be no improvement to pretend that they can be made perfectly definite by fiat, by patching up ‘our concepts’. It will be contrary to the essence of the whole enterprise to attempt to do any such thing. If a boundary is made sharper purely for the sake of taxonomical convenience, then it stands out as an arbitrary gloss on what is not arbitrary.
  9. Earlier in this chapter I considered what I called constraints on the formulation of criteria of identity for substances, and accepted as such a constraint a principle implicit in a part of Locke’s argument: identity over time is tied to unity at a time. If the rest of my argument approximates to the truth, we should need to add as a further constraint the principle that no two particular substances can be composed of the same matter at the same time37. For it is impossible to make sense of the suggestion that two distinct principles of material unity38 are embodied in the same matter at once, i.e. that the same matter is materially unified in more independent ways than one. Yet this point should provoke the thought that the description of such principles as ‘constraints on the formulation of criteria of identity’ is profoundly misleading simply in its implication that it is our choice of criteria39, even within limits, which determines the sortal’s ‘sense’. For the belief is thereby encouraged that the boundary to the individual substance is set, if under certain constraints, by our decision and stipulation, or by linguistic conventions. And that belief is much like Locke’s false belief that we arbitrarily set the boundary to each species of substance under certain constraints (notably, under the requirement that we do not construct a criterion of application out of properties which do not in our experience coexist). The point is that, when these ‘constraints’ on the stipulation of ‘criteria of identity'’ are fully set out, they are like the famous constraint laid by Henry Ford on his customers’ free choice of the colour of their cars: there is evidently no room left for stipulation or decision, individual or communal. It would therefore be better to adopt quite a different approach to the sense or meaning of sortals. Our recognition (p. 228) that their use is based on a presumption of natural specific boundaries (or, at least, of an underlying natural affinity or ‘real essence’) has led to a rejection of the doctrine that ‘criteria of application’ constitute part of the ‘sense’ or meaning of each sortal40, determining its denotation. Rather, the use of the sortal, and its meaning, depends on there being a natural class, the boundaries of which need be neither perfectly known nor perfectly precise, of things to be denoted. We need only recognize the corollary, that the use of a sortal such as ‘horse’ or ‘moth’ equally presupposes the existence of natural individuals falling into a class, in order to find reason for rejecting the doctrine that another contributant to a sortal’s ‘sense’ is something properly called a ‘criterion of identity’. That is to say, any ‘principle of individuation’ of a particular substance is to be sought, not in a ‘concept’, but in reality, as the causal principle of a unity which is material and real, not imposed and ideal. It is, indeed, more than a little misleading, as well as theoretically useless, to talk of the ‘concept’ horse: almost as misleading41 as it is to talk of the concept Bucephalus.


In-Page Footnotes

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