Diagnóstico de los Costos

Perhaps the most serious problem for the parsimonious account is one that Martin (2010: 219–22) himself considers. It is not unusual in philosophical discussions of perception to appeal to cases in which the appearance of an object is altered whilst its intrinsic properties remain unchanged. Hume famously used just such a case to argue that the direct objects of perception cannot be external physical objects, which ‘suffer no alteration’ despite changes in their appearances, but must instead be ideas or impressions in the mind (Hume 1999: XII.i, 201). This was later refuted by Reid (1997: VI.xxii, 186), whose response has since been taken up by Snowdon (1990) and others. However, this problem of conflicting or incompatible appearances also presents

a problem for Parsimony. If judgements about the sensible properties of objects

in the epistemically ‘good’ case are just judgements about their intrinsic properties, then how are we to explain cases in which an object’s sensible appearances change whilst its intrinsic properties do not? A paradigm example

of such a case is that of a stick that when partially immersed in water appears bent. That is to say, in certain respects from the relevant angle, it looks

relevantly like a stick that is bent would do under normal circumstances, i.e.

when it is not immersed in water (Martin op. cit.).

There are two obvious responses to this problem in connection with

Parsimony, both of which Martin rejects. The first is to claim that an object’s appearance depends not only upon its intrinsic properties, but also its relational properties. The appearance of the stick, for example, varies when it is partially

immersed in water due to its acquiring the relational property of being

immersed in water. This would be entirely in keeping with the principle of

Parsimony, which claims only that how an object looks is explained by reference to its appearance-independent properties, and not what kinds of properties these are. We can therefore identify two variants of the principle according to which types of properties are admissible in explaining looks

statements: (i) Relational Parsimony, according to which looks statements are

made true just by those properties of objects and their relations to objects that we need to appeal to in order to explain the truth of sentences that are not

explicitly looks sentences, and (ii) Non-Relational Parsimony: looks statements

are made true just by the non-relational properties of objects that we need to appeal to in order to explain the truth of sentences that are not explicitly looks sentences.

The problem with Relational Parsimony from Martin’s (2010: 220) point of

view is that:

[T]he ways of looking that the stick has just are among its basic visible properties, most saliently its length and shape, and potentially its surface colour. These simply do not change when it is placed half in the water Martin does not give any particular argument for this assumption, though he clearly aims to give the simplest possible account of our perceptual awareness of objects and their properties. Admitting that relational properties have an effect upon appearances would, perhaps, weaken the sense in which we can be said to be directly aware of the non-relational properties of objects, since various combinations of relational and non-relational properties can combine to produce the same or similar appearances. Such combinations, however, admit of a disjunctive analysis in a similar manner to disjunctive accounts of perception and perceptual illusion. On this view, the ‘bent’ appearance of the stick would be explained in terms of the distorting effects of the water in which it is immersed, the refractive properties of which combine with the shape of the stick to yield the resulting look. Thus, upon seeing a stick that is immersed in water, we veridically see the properties of the both stick and water combined, rather than just the shape of the stick. Presumably, however, even in the normal case, minute distortions from the air or other intervening medium would mean that

we rarely, if ever, saw the non-appearance properties of objects simpliciter. The

wish to claim that we have direct, and therefore unmediated, awareness of external objects in the normal case.

An alternative response would be to claim that looks statements are ‘principally reports of our psychological states’ (Martin 2010: 220). This view explains how objects can change in appearance without changing their non- relational properties in terms of the subject having entering a different psychological state. However, this would seem to imply that objects do not have any particular look when they are not being experienced, which is contrary to the way we use ‘looks’. This drawback could perhaps be avoided by a move similar to the one that Jackson makes in the case of phenomenal looks, with

each look corresponding to what subjects would experience were they to be

confronted with that object (4.2.5). However, this again involves identifying looks with the psychological responses of subjects, thereby weakening the sense in which perceptual experience can be said to deliver direct awareness or knowledge of external properties, and so is similarly inhospitable to Naïve Realism.

Martin’s own response to this challenge is to claim that the appearances of objects do not, despite evidence to the contrary, change. Indeed, he observes that ‘[i]f we endorse Parsimony, then we must reject the claim that the stick has changed in appearance’ (Martin 2010: 220). Instead, according to Martin, what changes is the appropriateness of asserting that the object has certain appearances according to the ‘perspective of comparison’ that one adopts (ibid. 221). On this view, the stick has both the property of ‘looking straight’ and ‘looking bent’, but one is only in a position to assert the former upon seeing the stick out of water, and the latter when it is partially immersed. The intrinsic properties of the stick that ground both appearances, however, remain fixed regardless of whether it is immersed or not. This position is highly counterintuitive since we can, and frequently do, say that the appearances of

objects change. However, it follows from Parsimony that if an object’s

appearance-independent properties do not alter, its appearance — or

appearances — must remain similarly fixed. In a sense, then, Parsimony entails

that objects possess all of the objective appearances that they can possibly have,

irrespective of which of these is currently available to observers at any given time. What makes it the case that things appear one way rather than another is instead the perspective or psychological state of the observer.

This unpalatable consequence of Parsimony, however, may be avoided since

the principle does not require that there be a simple one-to-one correspondence between perceptual appearances and the appearance-independent properties of objects. Instead, appearances may be realised by many different physical properties with the similarities between them being explained by the constitution and perceptual sensitivities of the subject. The ‘bent’ appearance of a stick in water, for example, need not be explained in terms of a single physical property that explains both the appearance of a stick in water and one that is genuinely bent. That we identify both appearances as forms of ‘bentness’ is not

intersubjective — similarity to paradigm cases of bent objects. Provided that such similarities are grounded in the relevant appearance-independent properties,

which may include the perceptual constitution of the subject, Parsimony is

maintained. In most paradigm cases of perception, however, such properties typically will be just the shape, colour, distance properties, and on so, of external objects. However, in cases of illusion or subjective similarity (e.g. the submerged stick), this need not be the case.

A modified version of Martin’s view may therefore be constructed in which changes of appearance are explained by the tendency of the human perceptual system to group appearances or looks together, based around certain paradigm

cases. What an object looks like — a comparative notion — is explained in terms

of its visual similarities to other objects, which in turn instantiate those properties of which they are paradigmatic. Precisely which objects constitute the

relevant paradigms will be a partly empirical matter upon which the Parsimony

theorist need not take a view. Indeed, it will not matter whether the relevant cases differ between times and subjects provided that the same sets of similarities are maintained. In that respect, a genuinely bent stick is as good an

exemplar of bentness as, for example, a banana.15 _{Thus, it is no objection to}

Parsimony that the resulting looks are equivocal, since this is an inevitable consequence of any comparative analysis of ‘looks’. Rather, it suggests that what determines an object’s appearance is its similarities to other objects. This in turn may be explained by reference to both the object’s and the perceiver’s

non-appearance properties, as Parsimony suggests. That we can describe the

presence of a particular appearance in terms of a potentially complex disjunction of physical properties is neither here nor there. Indeed, the problem with doing so will be precisely the representationalist’s difficulty in attempting to index p-representational content by visible looks (2.3.2). Provided that we identify looks with sets of similarities rather than looks-independent properties, however, this issue need not arise.