Both claims are a species of Realism in that they both claim an external world containing mind-independent physical objects. The first is broadly called `direct Realism'Foot note 1_2 and the second `indirect or representative Realism.' It is clear that what distinguishes the two kinds of realism is the veil of perception existent in the latter. It is that veil that led Berkeley to repudiate Locke's scientific Realism based on the impossibility of justifying a correlation between the percept and the mind-independent object that causes that percept -- there can be no resemblance between them, an idea can be like nothing but another ideaFoot note 1_3 (Hume has also claimed for the inescapability of a veil of perception pointing out the impossibility of making a step beyond appearances). Thus, in The First Dialogue, Philonous claims:
Berkeley is seen as the predecessor of Phenomenalism where one of its propounders, J.S.Mill, has claimed of material objects as being permanent possibilities of sensory experiences. The above views summarized can be restated thus (where R1 stands for a causal etc. relation between x and y):
(with respect to direct realism, indirect realism, and phenomenalism), and hence, that which can be seen is y (a perceived entity), that is, properties such as colour, shape, extension and texture. As it is apparent, there has to be drawn a distinction between sense-data and percepts. I follow Don Locke's ideaFoot note 1_5 that sense-data is a theory-neutral term. Thus, the formulation of the question should be whether speaking about sense-data is reducible to speak about percepts and if so in what way. Otherwise the question of whether phenomenal properties can exist unperceived would have no value whatsoever. In that case (if sense-data are percepts) they cannot.
If these are the only options, then we either perceive mind-independent objects in a direct way and thus we acquire information about these objects in an immediate manner or we are caught in a veil of perception and we are only acquainted with it, thus acquiring information for what there is beyond that veil (mind-independent objects) only derivatively, which is always forcing one to formulate a plausible account of the nature of the correlation (causal etc.) between appearances and the external world. Moreover, one must also provide a rationale for explaining the presence of a mind-independent world beyond that veil in that otherwise it will lead unavoidably to scepticism about the external world (to a refutation of the presence of a mind-independent reality beyond that veil). But why should we claim the presence of such private mental objects leading to a presence of a veil of perception in the first place?Foot note 1_6 What would a postulation of such entities serve?
A common-sense realist view of perception holds that secondary qualities are no less real than primary qualities.Foot note 1_7 Secondary or sensory qualities of objects are mind-independent. That is to say, colours, temperature, sounds, texture etc. are properties that physical objects possess independently of the existence of a perceiving subject. Moreover, the claim of course entails that the primary qualities of an object such as, shape, size, solidity, position, are of this kind. Thus, Aristotle claimed that the subject directly perceives properties possessed by objects and moreover,
It is clear however that such a contention faces severe problems. Objects in different contexts appear different. Their phenomenal properties change. It is implausible for one to maintain that he is directly acquainted with the actual properties that objects really possess (properties that appear different in different contexts have equal right in being considered as real since -- according to Aristotle -- we receive perceptible forms as wax receives the imprint of the ring without the iron or gold). Why should we therefore favour any of the received (perceived) properties?
Thus, besides the problems that the direct realist account faces with cases such as when one's perceptual error is due to a subjective standing of his perceptual state, and also, in cases of hallucination, where there might be no presence of an external object whatsoever,Foot note 1_9 there are cases where there is an objective standing of phenomenal properties, that is, in these cases as in the cases of veridical perception there is an interpersonal convergence in judgment. The case of the bent stick in the water, the white expanse of the wall that under certain conditions of illumination looks red, or the case of the rectangular surface of a table which, viewed from a certain angle, its two opposite lines appear to converge, are cases of such an interpersonal convergence in judgment.
Now, the stick cannot be both straight and bent, the expanse of the wall both white and red and the surface of the table both rectangular and not-rectangular. There are however, no distinguishing marks between the two perceptual states in each case. The objective phenomenal standing of both cases (veridical perception and perceptual error) enables one to suggest that with what one is directly acquainted is not a property of the object i.e. of an aspect of the world, but rather a mental item. Hence, the postulation of such entities, private mental objects, serves to explain the case of the perceptual error. With what one is directly aware (or acquainted) is appearances, and not the real properties of objects. This objection, especially when it comes to perceptual errors with an objective standing, looks devastating to a naïve realist analysis of perception.Foot note 1_10
The direct realist next move is to appeal to modern science. The claim is that the `real' properties of objects are not appearance-determined or perceiver-dependent. The identification of the `real' properties of objects has to be done not by appealing to the perceptual state of the perceiving subject but rather by an appeal to the real character of the properties of objects as it is identified by science. Modern science tells us that the constitution of colour is light of a certain wavelength, of heat is molecular motion etc. A closer look to what modern physics has, as regards light and matter, is of importance.
Light is referred to as electromagnetic radiation because the nature of light is based on tiny electromagnetic fields, called photons. These photons of light can have many different energy levels or wavelengths, which are expressed in nanometers (nm). Light has properties both of a particle and a wave. In the case of the visible wavelengths, every wavelength is represented by a different colour. Visible light takes up only a tiny fraction of the electromagnetic spectrum, that between ultraviolet and infrared light (heat). Now we see things as a colour because objects typically absorb all light except one particular wavelength of light or colour. That wavelength (colour) is reflected off the object and absorbed by our eyes, hence we see the object as being the reflected colour.Foot note 1_11 As regards matter, all matter is made up of various combinations of three elementary particles: protons, electrons and neutrons. Electrons have wave properties similar to those of light. All matter is in a state of perpetual activity. There is no dividing of matter and force (energy) into two distinct terms, as they are one (the matter/energy distinction of a given phenomenon is relative to the inertial frame of the observer).
Now if one points out, when referring to an expanse of the wall with which one is directly acquainted and which looks red, that `this expanse is not really red', one would not be taken as uttering an inconsistency. There may be bizarre conditions of illumination of which the agent is aware. Similarly, a distant object looks small and the shape of an object varies according to the conditions of observation. Moreover, objects in the everyday life are often obscure, or only partly visible. Thus, different perspectives commit one to different verdicts concerning an object's shape, extension and texture. Indeed, if we are to employ a microscope the texture of the object looks different. Moreover, viewed from different angles the shape of an object looks different. Therefore one's claim that `the surface of this table is actually rectangular' when its two opposite lines appear to converge makes perfect sense.Foot note 1_12
Phenomenal properties of an object therefore do change with respect to different contexts. In addition, the potential phenomenal character of these qualities such as colour, shape and texture is intrinsically the same. This is to mean, as in the case of colours that microphysical structures of the objects have a permanent disposition of reflecting light of certain wavelengths respecting to different contexts, and they therefore appear differently coloured, in the case of shape, size and texture they do also have a permanent disposition to appear in a certain manner as regards to different contexts. As nothing can be round and square at the same time, nothing can be blue and red at the same time. The colour of an object, (the colour it appears to be), is not due to chance. The colours (visible wavelengths) that it absorbs or reflects are determined by the atomic and molecular structure of its surface.
The claim that we can measure (and thus confirm) the, say square, shape of an object, whereas in the case of light of a certain wave length we cannot verify its redness is evidently false. It is that which differentiates colour judgments from moral judgments. A utterance of the kind `x is red' by normal humans in the same context requires an interpersonal convergence in judgement (with no deliberation whatsoever). It is self-explanatory. He, who cannot discern that `x is red', in a certain context, ipso facto has a certain kind of deficiency. Moreover, to assert that a colour is actually light of a certain wavelength (respecting each colour) is to imply at the same time that there is a scale upon which colours can be placed according to different wavelengths and in case of the application of a form of measurement of light (e.g. spectrophotometers are used for colour measurements), or of the arrangement of the microphysical structure of the surface of the object, science can identify the `real' colour of an object.Foot note 1_13
`Colours as seen' exist only when perceived. Light of a certain wavelength appears to one red. An animal may perceive it differently. The snake `sees' the heat of the body of living creatures. That is, as in the case of the colour temperature in humans, it perceives heat colourfully. A close examination to a green dress will show that the dress is not really green (the range of the colour spectrum is expanded). In addition, the texture of an object if we employ a microscope looks different. A modern electron microscope can just about see individual atoms. Is this to mean that objects are really such as we see them without the microscope solid and rigid (in that we do not perceive the tiny particles that constitute them) whereas colours are not as we see them and actually objects are colourless? Why should we only withdraw the first claim and maintain that there are objects as we see them (though soundless, colourless etc.) existing independently of a perceiving subject? If the world is constituted by tiny particles and what we perceive is objects, why should we not claim that there is indeed a veil of perception where, whereas there are such things as light of certain wavelength, tiny particles, electric charges, sound waves, molecular motion, we instead perceive colours, objects, sounds, heat and so forth, and not reality as such. If there were no perceiving subjects and thus there presumably be no red and only light waves why shouldn't also be no tables and cars but instead tiny particles and electric charges?
Strawson makes an attempt to reconcile the naïve realist view(stated above) with a form of scientific realism. He claims:
Now, it is not hard to see why Strawson's attempt actually amounts to a potential reconciliation between common-sense realism and indirect realism. This can be illustrated more clearly if we state first what scientific realism holds.
For a scientific realist `colours as seen' `sounds as heard' etc.(appealing to the Lockean picture of secondary qualities) cannot exist in the absence of the perceiving subject. The claim (in a reductive form) identifies colours with distinct light waves in terms of a disposition of the microphysical structure of a surface to reflect light of a certain wavelength in certain conditions. That is to say that redness (similar considerations hold, as shown above, for sounds, heat, taste and also size, shape and texture) is a permanent possible cause of the experience of seeing red. I'm therefore able to perceive the red colour of the chair (appearing red to me) due to the manifestation of a certain disposition that the surface of the object possess, that is, according to the context in which I perceive the object in question, its surface reflects light of a certain wavelength.Foot note 1_15
Now, what we are left with? What is that which ultimately remains constant in this object and which possess the dispositions to manifest all these properties? It is plain, that what is left of the object as we know it, is hard even to conceive. If therefore scientific realism claims of the object as being a set of dispositions to be manifested under certain conditions based on an unconceivable reality where there holds a correlation between `seeing red' and the disposition of such a reality to cause that sensation, in what respect then would that account differ from an indirect realist account? It appears therefore that a claim of the kind `ys are to be identified as a set of dispositions manifested according to certain contexts' cannot escape of falling into (ii) as stated above. Such an attempt of reconciling direct realism with the indirect variant (by simply invoking different perceptual viewpoints) simply won't do. It is incoherent. Therefore clause (i) is rejected.Foot note 1_16
I turn now to (ii). The Lockean variant of indirect realism (representationalism) holds that:
In short, representationalism holds that that which is immediately perceived is caused by that which is mediately perceived, and further, the former resembles the later (the Lockean primary qualities). However, the notion of such a resemblance is hardly graspable. Appearances, that is phenomenal properties, can be y1 at t1, y2 at t2, y3 at t3 and so forth (according to different contexts), where y1 ≠ y2 ≠ y3. Is this to mean that the object has at t1, t2, t3 different primary qualities? For the representationalist the resemblance holds only in the case of the veridical perception. As we saw earlier the argument from illusion and modern physics were the primary reasons for the direct realist analysis of perception to be rejected. That was also the reason for the postulation of mental objects.
But how is it that these objects resemble reality (external objects) in the case of veridical perception? The external object appears to be three-dimensional and the mental object is suggested to resemble spatial properties of the external object such as shape, size, distance and direction. Private mental objects cannot be three-dimensional. Can it be a case similar to the relation between a picture and its object? The picture shows how the object looks like, it does not resemble the object. What the picture resembles is the object's phenomenal properties not the primary ones. Therefore (ii) with the form of representationalism is rejected.
The veil of perception therefore consists of the appearances (the phenomenal properties) of objects, that is, in a reductive manner, of sense data (if we are to exclude the first two cases of illusion stated above). Sense-data alter with respect to a different context. Phenomenal properties of the objects must be these properties that change with respect to a different context and these properties cannot be the intrinsic properties of the object. That is to say, properties without which an object cannot exist, or properties without which, an object cannot be the same object. Thus an object, the same object, can have different colours (as we perceive them), different texture different shape etc, and it still remains the very same object.
In different contexts an object appears different. Sense-data differ, it is though evident that the object in question remains the same object. There has to be thus something that remains constant in this object or something which is intrinsic to it and which could identify this object in every physically possible context. We might claim then of secondary qualities as the properties that alter in virtue of a different context, and of primary qualities as the intrinsic properties of the object.Foot note 1_18 It is not the case that particles of light (photons) are seen in the everyday life as it is also not the case that electrons, protons etc. are seen either. In addition, to think of the colour of an individual atom is meaningless. This is roughly an order of magnitude too small for it to reflect light on its own -- the light wave is too big to be reflected and show us colour. Furthermore, modern physics tells us that matter is capable of infinite subdivision. This is why Russell was so right when he claimed (with reference to an object's texture) that if we are not to trust our naked eye in what we see why should we trust the microscope.Foot note 1_19
If however, there is nothing to remain constant or in the case that there is no intrinsic property that an object has then what could give justice to the claim that the object in question which appears different in different contexts, is that very object, and `appears' is not to be considered as `is'? But then what is still to perceive x if y varies? Is there any point at all to argue that x remains the same when y varies? That is to say, if, for instance, we accept that the real colour of an object is that under inspection in `normal circumstances', e.g. green, and not the one that appears under a closer look where the range of the colour spectrum is expanded, then to hold that `of an x, y may vary whereas x remains that x' would be absurd. Variability comes in two levels. For an object x, if z is its dispositional propertiesFoot note 1_20 and y that which is perceived (shapes, colours, heat etc) then z, y may vary. Veridical perception occurs when statements about y can be reducible to statements about z. I say more on this in the remainder of the paper.
Consequently, it appears that we are indeed inescapably caught in a veil of perception. The fact that one perceives only ys seems to show that one is actually caught inescapably in that veil. It certainly looks hard to consent to but appears that one has to. Again though, there appears the problem of identification. That is to say, what is for an x to be that x in every possible context. What is that which remains constant or to put it differently what is that makes statements of x to be of that x when z and y may vary without render these statements senseless? It is plain that there is no room for (iii) as a plausible candidate. It appears that the grounds for the identification of an object, in different contexts, can be given only by a realist analysis of a material object.
Perceptual experiences that may be caused in us differ from a permanent disposition to behave in a certain manner. Thus, manifestations of the dispositional properties of objects according to different contexts appear to function as identity determinants. That is, object B and object C manifesting dispositional properties γ and δ respectively, according to a certain context, where γ=δ is also B=C. That might lead us to provide an account of what is for an object to be identical with another. But our primary concern here rather is, what is for x to be that x in different contexts, or to put it differently, how a particular object is to be identified throughout different contexts. Before I proceed, it would be of importance to stress that according to what I've said so far, z is an objective standing property (not to be confused with phenomenal property). It can exist independently of a perceiving mind. The fact that it is causally related to a non-dispositional ground is not to mean that (as it is shown) it cannot consist of a non-dispositional molecular structure. To put it differently, the fact that α1 is causally related to α2 is not to mean that they cannot have the same nature (an event is causally related to another event and matter is causally related to matter).
Now to our primary concern, namely, what is for x to be that x, in different contexts. I could perhaps suggest the following: An x (object) is that x, when with respect to a certain context x manifests z dispositional properties, perceived by a subject as y (appearances), on a basis of permanent non-dispositional properties n, where n is identifiable with z and vice versa. It could only be identified thus. To say that the world only contains ns is certainly inconceivable. In addition, to say that zs are sense-dependent is to be confused with ys. Zs are out there, ready to be perceived.Foot note 1_21 Furthermore, it will be of interest to attempt to provide an account of what is for A to perceive that x with respect to different contexts. Thus, for objects x1, x2, xv that cause phenomenal properties of an objective standing (veridical and illusory perception) y1, y2, yv to A, with respect to a certain context,Foot note 1_22 if y1 ≠ y2 ≠ yv then it is also x1=x2=xv. This cannot be other than a self-identity relation. It is plain that what is for A to perceive that x depends on what is for x to be that x.
For a more clear grasp some further remarks might be of some help. The key point to my considerations is zs. I have considered zs as objective standing properties (i.e. aspects of the world), and not as phenomenal. In addition, zs are manifested properties of the objects (sensible properties) and not permanent causes of appearances. Furthermore (as argued), they can have the same nature with the non-dispositional properties of an object (the intrinsic properties of it) ns, as stated above. As regards perception, whereas in Locke's representationalism is claimed that an object x stands in a relation to a subject (more precisely, in my account, ns R2 A), I suggest that the relation is between the subject and the mind-independent zs which are causally related to ns (zs R2 A).Foot note 1_23 The subject is not (directly) related to mind-independent -- non-dispositional ground n, but rather to much more intelligible and comprehensible mind-independent (manifested) properties of the object, z. Now the four categories of illusion are as follows:
As a concluding remark, the identification of colour properties, is not to be done as in the case of the dispositional theory of colour with the disposition (with the microphysical structure of its surface) of the object to emit light of a certain wavelength but rather with the manifested property. In this case with the light emitted from the surface. That is to say, not with the dispositional properties of the objects but rather with the manifested properties (manifested properties though are not to be confused with appearances). With that formulation McGinn's point of the inescapable of an error theory of colour perception (concerning a dispositional theory of colour) is inapplicable.Foot note 1_24
Bibliography
[Foot Note 1_1]
I'll concentrate on that which can be perceived i.e. that which literally can be seen, heard, touched etc. Objects and more particularly properties of objects and not events or situations. And moreover `seeing' and not `seeing that'. To this one might reply with reference to D.M.Armstrong's twofold claim (for a reference see my bibliography) that mediate perception involves inference whereas immediate perception involves no element of inference and that all perception is the acquiring of beliefs. Whereas there is a whole lot more to be said as regards the distinction I will only point out two things. First, not all perception involves belief as the cases of walking (e.g. side-stepping of trees) and driving show, where the subject may be unaware of what she has perceived. Answers in terms of the presence of unconscious inference or of inclinations to believe do not seem persuasive enough. And even if one accepts that such cases can be somehow explained by the presence of unconscious inferences or beliefs there are cases where there is an illusory appearance p even when the subject has a justified belief that not-p (e.g. Muller-Lyer case). Second, The misapprehension of the distinction between `seeing' and `seeing that' (the belief about perception or the interpretation of that which is perceived) or between cognitive (conceptual) content and content that involves necessarily belief is the reason for postulating a necessary involvement of inference in the case of mediate perception whereas in the case of immediate not.
[Foot Note 1_2]
It is claimed however to be subdivided to a scientific form of direct realism and to a very close view labelled naïve realism or common-sense realist view.
[Foot Note 1_3]
In Berkeley's The Principles of Human Knowledge, section 9.
[Foot Note 1_4]
In Berkeley's Three Dialogues Between Hylas and Philonous, p. 169.
[Foot Note 1_5]
For a discussion see Locke's Perception and Our Knowledge of the External World.
[Foot Note 1_6]
Derivatively, what would be the properties of such entities?
[Foot Note 1_7]
I say more on the distinction later on.
[Foot Note 1_8]
Aristotle, De Anima, p. 42.
[Foot Note 1_9]
The direct realist here appeals to the distinction between sensation and cognition but that is an issue that needs separate discussion. Later on, I separate illusion into four categories.
[Foot Note 1_10]
See third case of illusion at the end of paper.
[Foot Note 1_11]
Light is attracted by gravity, it is deflected. The deflection of light is immediately related to the decrease of its speed. Mass and energy are not two separate things but rather they could be traded one for the other (the conversion of mass to energy could account for the enormous energy output of the stars). Moreover, nowadays, there are several physical processes that can accomplish that, that is, to realize this potentiality; and further, the light can provide detailed information about distant stars and planets, e.g. distance, speed, rotation, chemical makeup etc. as also sounds (being wave motions), can give us information not only on the sources from which they originate, but also on the bodies through which they pass, and against which they are reflected or deflected.
[Foot Note 1_12]
What one perceives in both cases, namely, the `convergence of the two opposite lines of the table' and the `red expanse of the wall' do not differ in nature. In both cases things appear to be different than they really are. The subject perceives them both (as in the case of the stick looking bent in the water) as being the case. Special conditions (specified differently in each case) lead a putatively unaware subject, or one with no past experience, to believe that the two opposite lines of the table do converge, the expanse of the wall is red and the stick is indeed bent (a subject unaware of `p is not true because of q' or of `perceptual experience p misrepresents reality for the reason that conditions q obtain' would take these perceptual experiences as being the case). That is, all three perceptual states do not differ in nature.
[Foot Note 1_13]
Likewise, in the case of temperature as an alleged secondary quality, one may feel as having fever or high temperature, however the employment of a thermometer might show that actually his temperature is normal. Moreover, a claim that an object has a certain shape or size (as in the case of colour) can only be contingently true whereas a claim that there exists a non-dispositional molecular structure on the grounds of which, such dispositional properties of the objects are manifested, appears to be necessarily true.
[Foot Note 1_14]
And moreover: «`This smooth, green, leather table-top', we say, `is, considered scientifically, nothing but a congeries of electric charges widely separated and in rapid motion'». In his Perception and its Objects, pp. 110-111.
[Foot Note 1_15]
The dispositional theory of colour holds that for an «object to instantiate a colour property is for it to have a disposition to cause experiences as of an object having that property in normal perceivers in normal conditions». In C. McGinn's Knowledge and Reality -- Selected Essays, p. 298. McGinn however rightfully suggests that phenomenology of colour perception contradicts such an identification, namely colour properties do not look much like dispositions to produce colour experiences and thus an error theory of colour perception comes to seem inescapable. I will come back to this point later on.
[Foot Note 1_16]
It might be objected that Strawson's account can be put in terms of the Fregean sense-reference distinction. That is to say, in the case there is an absolute physical property of an object P we perceive it in a qualitative manner Q (e.g. `colours as seen'). Q is not itself an object of perception but rather it is a mode of presentation of P. Thus, in terms of relativity, what Q presents depends on our occupying a certain point of view. The account however fails with respect to the third case of illusion (stated above) which is stated more clearly at the end of paper.
[Foot Note 1_17]
John Locke, An Essay Concerning Human Understanding, pp. 69, 370.
[Foot Note 1_18]
This applies to Berkeley's argument of the indiscernible of primary and secondary qualities (as having the same status) in his Principles of Human Knowledge, wherein not managing to show that these qualities cannot be mind-independent, arguing thus, enables one to ask how, provided that an object has certain qualities (such as a distinction of primary and secondary qualities is inapplicable), are we to identify that object in a different context where its qualities (or some of them) have changed? Further, by what means can one be aware of such an alteration? I meet that point later on.
[Foot Note 1_19]
Notably, there is also the view that matter after a certain point of subdivision `falls' inevitably into energy (quarks may be destroyed and hence no further subdivision). But even the very notion of a' quark' is characterized by its relations to other physical entities. The same holds for other physical properties (e.g. mass). That is, they are characterized by certain dispositional roles and relations to other physical entities. But physics says nothing about the intrinsic properties of such physical entities that could ground their dispositions. Hence, rightfully follows the question: Can a physical entity have a certain dispositional role (be characterized by that role) without at the same time having any intrinsic properties to ground its dispositions?
[Foot Note 1_20]
Zs are to be taken into account as manifested properties (sensible properties e.g. light of a certain wavelength) and not as permanent causes of appearances.
[Foot Note 1_21]
That there are such things as molecules (constituents of objects), which have a certain arrangement has been very recently warranted by direct evidence (after the electron microscope invention), however this claim is a very old one, with an indirect theoretical establishment, that is by inference. Science has shown in the past, as in present, to be successfully led by inference from that which can be seen to that which cannot. To conclude:
[Foot Note 1_22]
With two provisions:
[Foot Note 1_23]
Notably, R2, stands for a functional, causal etc. relation between the subject A and ns and zs respectively.
[Foot Note 1_24]
It is worth to note cases where people who are born blind and recover their vision, experience colours which at first float and are gradually bound to objects.