Understanding Realism

AC Grayling

The confusion infecting the realism debate arises from thinking of given realms of entities in two different ways at once, or more precisely, from conflating two ways of thinking.

The first way is familiar enough in its various guises as a metaphysical commitment, typically to a notion of substance; but it is difficult to state precisely. It consists in thinking about the entities in a given realm as existing in their own right, independently of other things which cause or, more weakly, sustain them in being. Such entities might be conceived as having the status of something like Aristotle's primary being, or at any rate as substances conceived as those things (or that thing, for monists) which exist, and can only be understood as doing so, in some sense in and of themselves. This thesis is sometimes been called 'metaphysical realism'. I shall refer to it as thesis A. Some of the more heroic moments in the history of philosophy consist in efforts to clarify it, for what is at issue, after all, is no less than the metaphysics of being. But I am not confident that there is clarification ready to hand. The following hints at the difficulties.

Understandings of thesis A fall into at least two broad categories. Formulations like 'existence in its own right' and 'absolute and ultimate existence' suggest a full Aristotelian concept of primary ousia. This is existence which is basic to other, derivative, existence; it at least explains itself, and perhaps indeed - as in theological employments of the notion - it causes itself. It is not obvious, without further taxonomy, whether the latter, stronger, notion is coterminous with the notion of necessary being, but apologists at any rate standardly so construe it. A reason for caution is that giving a negative answer to the question: could there not be a conception of contingently self-caused beings, in the sense that other facts about the universe do not necessitate their existence? is not obviously called for by the terms of the question itself. For there might be nothing contradictory in a description of the universe, whether false or not, in which the existence of certain self-caused beings is denied; and the reverse would have to be true if the entities in question were to have a chance of being necessary in the required fashion. But no-one need go out on an ontological limb in this way to get a notion of 'existence in its own right'; there is always an epistemological limb to venture along, which says that it is just a brute fact, to be accepted as primitive, that there are certain things which exist in this primary way. To make it metaphysical realism which the thesis thus understood amounts to, a bruteness claim has to be taken as a candidate for literal truth. [The idea of explanatory self-sufficiency is an epistemic notion, note; which shows the close connection between these ideas, as a supposed explanation of epistemic independence, and that thesis itself as discussed below.]

Or thesis A might be taken more weakly to mean that, having been caused, a thing X exists as a genuine individual whose dependence on other things, for example food supplies if X is an animal, is only necessary in the sense of physical law, and hence is metaphysically contingent. It might be a fact that X is in this way dependent on things external to itself; but the point is that any suitable external will do, so there is nothing to which X's dependence is metaphysically annexed. Of course it could be argued that X is dependent on a class or classes of things - say, foodstuffs - but this does not alter the descriptive adequacy of treating X as an individuable existent. Consider a pebble: in what sense can it be understood as a dependent individual once its causal history - its having been produced by cooling lava, say - has been discounted? In this guise the thesis aims at asserting the ontological irreducibility of X to its material and efficient causes, and the ontological definability of X in a scheme of things, with its own path through a world, say, or its own separately countable membership of it. This second aspect of the notion is a rich one, for it plays a part in a story whose other themes - individuation, identity, particularity - are familiar indeed. The idea of individual substances has its busiest employment precisely here. The connection between the two aspects is that asserting X's independence in this sense means that X is to be understood as not essentially or internally related to anything else, of which it must therefore be considered part or along with which it has therefore to be individuated. So it is a true individual.

The question of how, if at all, these two understandings of thesis A are related is a matter of controversy. One can hold some version of either without any entailment to versions of the other. The chief reason is that an ontology [a theory of what there is] can select a range of individuable, persisting and therefore reidentifiable particulars, whose status as such is entirely determined by their relation to a theory or point of view which finds it convenient to treat them as such, without concomitantly holding that these things are in any way ultimate. This is the case with the medium sized dry goods constituting the ontology of mundane experience. No-one I think would now claim that according them the status of basic particulars in our scheme (see Strawson, Individuals) means that they are the ultimately existing entities simpliciter. This would imply, for one thing, a new order of instrumentalism about physics. Given that the basic particulars of a scheme might well be epistemically but not ontically basic, and in acknowledgement of the difficulties attaching to getting to the latter from the former, some - even some contemporary (see the familiar pessimistic views of McGinn, Nagel) - philosophers hold that the veil of the former is impenetrable, and we are condemned to ignorance about how things really are.

There have however always been more optimistic metaphysicians, whose ambition is to identify what is or has to be basic in the sense of the first understanding of thesis A, and then to explain how whatever seems basic in the second understanding of A is connected to it - perhaps, at the neatest, by being smoothly reducible to it. The denotata of referring terms in folk psychology, for example, are for some [the Churchlands e.g.] dummies, typically misleading ones, for referring terms in a future perfected science which will pick out something ultimate, deeper even than the physiological level at which attempts at explanation currently aim. [There are competing candidates: Leibniz's monads are an historical example. Only those persuaded that physics is metaphysics will think that fluctuations in the quantum field or superstrings - or whatever next - have that sort of ontological status.].

The serious difficulty with A is that there just does not seem to be a precise way of making the notion of 'ultimate existence' or 'existence in its own right' intelligible. It obscures rather than helps to speak, as we have seen, about ultimate things as uncaused, or self-caused, or necessary, or primary, or basic, or a brute fact. The argument of the metaphysicians is that because there is something, there must be something ultimate, in a sense of 'ultimate' vaguely connoted by the foregoing expressions; and they draw this conclusion because they feel that a 'ground' of being is needed for what there is, which either needs no ground itself or is its own ground. [Compare styles of cosmological argument, which employ notions of causality and contingency to just this end.] And anyway, talk of grounds keeps us firmly in the realm of metaphor. Another, allied, symptom of the problem is that efforts to give this family of notions content turn quickly into appeals to a different notion, namely, epistemological independence, discussed shortly. This is shown by ready allusions to 'explanatory' ultimacy, which at least often substitutes for the purely existential account being sought. But whereas questions of explanation mark out a logical space in a genuine problem, the metaphysical side of the ledger seems to stay blank.

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