color, space and figure in locke - berchielli

47C O L O R , S P A C E , A N D F I G U R E I N L O C K E

Journal of the History of Philosophy, vol. 40, no. 1 (2002) 4765

[47]

Color, Space, and Figure inLocke: An Interpretationof the Molyneux Problem

L A U R A B E R C H I E L L I *

THIS IS HOW LOCKE, in the second edition of his Essay Concerning Human Understand-ing (1694), introduces a question that had been suggested to him in a letter fromWilliam Molyneux:1

. . . I shall here insert a Problem of that very Ingenious and Studious promoter of Knowl-edge, the Learned and Worthy Mr. Molineux, which he was pleased to send me in a Lettersome Months since; and it is this: Suppose a Man born blind, and now adult, and taught by histouch to distinguish between a Cube, and a Sphere of the same metal, and nighly of the same bigness,so as to tell, when he felt one and tother, which is the Cube, which the Sphere. Suppose then the Cubeand Sphere placed on a Table, and the Blind Man to be made to see. Quaere, Whether by his Sight,before he touchd them, he could now distinguish, and tell, which is the Globe, which the Cube.2

In the standard interpretation of the Molyneux problem as presented in Locke,the question is always linked to the general issue of differences in the ideas offigure received by the various senses. This interpretationput forward by Berke-ley3 says that for Locke, the ideas of figure produced by sight are specifically

My thanks to Maddalena Bonelli, Richard Glauser, James Hill, Ambroise Lombard, FrancoParacchini, and Paolo Spinicci for commentaries on an early version of this paper.

1 Molyneux was an Irish scholar and politician. He wrote an important treatise on optics, DioptricaNova (London: Benjamin Tooke, 1692), as well as several essays in the Philosophical Transactions. Cf.Letter of March 2, 1692/3 in E. S. De Beer, ed., The Correspondence of John Locke (Oxford: ClarendonPress, 1978), vol. IV, letter no. 1609. The question had already been suggested in a previous letter(Ibid., Letter of July 7, 1688, vol. III, letter no. 1064), where he also took up the problem of dis-tance, because he wondered not only whether a blind person would be able to recognize and name acube and a sphere, but also whether he could know by his sight, before he stretched out his Hand,whether he could not Reach them, tho they were Removed 20 or 1000 feet from Him?

2 J. Locke, An Essay Concerning Human Understanding, Peter H. Nidditch, ed. (Oxford: ClarendonPress, 1975), Book II, Chapter ix, Section 8. Hereafter cited in the text by Essay followed by book,chapter, and section number.

3 According to this interpretation, a negative response to Molyneuxs question entails a specificdifference between the ideas of figure received via sight and those received via touch: Now, if a square

* Laura Berchielli is Junior Lecturer at the University of Neuchtel.

48 J O U R N A L O F T H E H I S T O R Y O F P H I L O S O P H Y 40: 1 J A N U A R Y 2 0 0 2

different from those produced by the sense of touch. This interpretation is par-tially justified by the response suggested by Molyneux to his own question, a re-sponse approved of by Locke:

To which the acute and judicious Proposer answers: Not. For though he has obtaind the experi-ence of, how a Globe, how a Cube affects his touch; yet he has not yet attained the Experience, that whataffects his touch so or so, must affect his sight so or so; Or that a protuberant angle in the Cube, thatpressed his hand unequally, shall appear to his eye, as it does in the Cube. I agree with this thinkingGent. whom I am proud to call my Friend, in his answer to this his Problem . . . 4

The specific distinction Locke supposedly refers to is sometimes thought torelate to a difference among the number of perceivable dimensions. The idea isthat in Locke, only the sense of touch can receive ideas of three-dimensionalfigures, whereas sight always receives two. Therefore, when we believe we see athree-dimensional space or shape, what in fact happens is that we are making ajudgement that moves from a visual to a tactile idea of figure.5

This standard interpretation is, in my opinion, inadequate. It presupposes aspecific distinction between ideas of shape received by sight and those received bytouch, and this distinction does not exist in Lockes philosophy. Indeed, asidefrom the passage in which Molyneux replies to his own question, nowhere inLocke does one find any reference to any sort of heterogeneity among visual andtactile ideas of space. Maintaining that such a distinction is a theme in Lockewould depend upon an isolated case in the Essay. Rather than placing the empha-sis on the differences between the two senses in the Essay, Locke stresses the mu-tual capacity of sight and touch to perceive the shape of bodies. Not only are ideasof figure simple ideas we can receive and convey into our minds . . . both byseeing and feeling,6 the very definition of the idea of figure considers sight andtouch to be the two senses capable of perceiving the shape of a body. When onetakes into account the whole of Lockes Essay, it becomes difficult to accept theexistence of two heterogeneous ideas of figure, whose differences support hisnegative response to Molyneuxs question.7

surface perceived by touch be of the same sort with a square surface perceived by sight; it is certain theblind man here mentioned might know a square surface, as soon as he saw it . . . We must thereforeallow, either that visible extension and figures are specifically distinct from tangible extension andfigures, or else, that the solution of this problem, given by those two thoughtful and ingenious men, iswrong. G. Berkeley, New Theory of Vision, in A. A. Luce and T. E. Jessop, eds., The Works of George BerkeleyBishop of Cloyne, 3 vols. (Nelden: Kraus Reprint, 1979), vol. 1, sect. 133. From now on, I will refer tothis work as NTV and the section number.

4 Cf. Essay, ix, 8.5 Cf., among others, M. Ayers, Locke, 2 vols. (London: Routledge, 1991), vol. 1, 65-6; M. Lievers,

The Molyneux Problem, Journal of the History of Philosophy 30, no. 3 (1992): 399-416, 410; J.-M.Vienne, Locke et lintentionnalit: Le problme de Molyneux, Archives de Philosophie 55 (1992): 661-72, 684; M. Bolton, The Real Molyneux Question, in G. A. J. Rogers, ed., Lockes Philosophy. Contentand Context (Oxford: Clarendon Press, 1994), 75-99, 98; M. Degenaar, Molyneuxs Problem (Dordrecht:Kluwer Academic Publishers, 1996), 25.

6 Essay, II, v; see also Essay, IV, xi, 7: Thus I see, whilst I write this, I can change the Appearance ofthe Paper; and by designing the Letters, tell before-hand what new Idea it shall exhibit the very nextmoment, barely by drawing my Pen over it.

7 According to some commentators, the negative response to Molyneux also contradicts theprinciple of resemblance between primary qualities and ideas of primary qualities. (See, among oth-ers, Ayers, Locke, vol. 1, 65; and Vienne, Locke and lintentionnalit: Le problme de Molyneux,669.) They state that 1) if the visual and tactile idea of the same square must each resemble the square


One might suppose that for Locke, the Molyneux question is strictly concernedwith the characteristics of processes whereby we construct general abstract ideas.His negative response to Molyneux would then spring from a nonconformity be-tween the first visual experience of the cube by the newly cured blind man and hisgeneral idea of a cube. However, this hypothesis does not hold up, for it thenmakes little sense that Locke places Molyneuxs question in Chapter IX, on per-ception, rather than wait for Chapter XI, which takes up abstraction and its mo-dalities.8 Moreover, this explanation does not correspond to the reasons Lockeprovides for inserting the question:

. . . as on occasion for him to consider, how much he may be beholding to experience,improvement, and acquired notions, where he thinks, he has not the least use of, or helpfrom them.9

The main aim of this article is to examine Lockes writing on visual and tactileperceptions of shape and space. According to my reading, which is based prima-rily upon the first edition of the Essay, Locke grants that it is possible for sight,under certain perceptual conditions, to receive ideas of three-dimensional fig-ures (Sections 2-3 of this paper). This modifies standard interpretations of theMolyneux question. In my opinion, Locke makes use of Molyneuxs question inorder to discuss the relation that exists between ideas of color, on the one hand,and ideas of shape which are drawn by the edges of color on the other. Seen inthis way, the Molyneux problem no longer concerns the relation between spatialproperties as perceived by sight and spatial properties as perceived by touch. In-stead, it becomes a way of addressing the relation between color and space in allits aspects (Sections 1 and 5 of this paper).10

itself, then they must also resemble each other; and 2) if two things resemble each other, then theymust be ackowledged as being alike. However, even if the relation of resemblance is transitive, it is notthe case for appearing to resemble. Thus, two things can resemble each other without appearing toresemble each other. Molyneuxs problem relates to the recognition of resemblance, while the prin-ciple of resemblance between primary qualities and the ideas of primary qualities relates to a resem-blance that is not immediately perceivable and is established a posteriori. In addition, even if the resem-blance between two shapes were recognizable, this would not necessarily imply an affirmative responseto Molyneuxs question: any resemblance may be accompanied by a difference, and such a differencemight be the basis of a negative response to Molyneux.

8 Essay, II, xi, 911.9 Essay, II, ix, 8.10 This way of interpreting the question recalls J. Brunschwigs interpretation of the conception

of common sense in Aristotle. According to Brunschwig (En quel sens le sens commun est-il commun,in C. Viano, ed., Corps et me. Sur le De Anima de Aristote [Paris: Vrin, 1989], 189-218): a koins such asmotion is felt if and only if it is felt in common with what is felt specifically by sight, or in common withwhat is felt specifically by touch, or by hearing, etc. This is precisely what the word koins means. If thekoin are always felt in common with one dia or another, they are always felt by one of the specificspecial senses devoted to the perception of these dia, and the status of a unique common sense,responsible for the perception of the dia, becomes superfluous and thus problematic 194-5 (mytranslation). In fact, in Locke there are common sensibles without a common sense. Cf. G. Brykman,Sensibles communs et sens communs chez Locke et Berkeley, Revue de Mtaphysique et de Morale 96,no. 4 (1991): 515-29, 516.


1 . T H E M O L Y N E U X P R O B L E M A N D T H E R E L A T I O N O F C O L O RT O S P A C E : T H E F I R S T E D I T I O N O F T H E E S S A Y

The importance of the color-space connection becomes obvious upon a readingof Sections 8 and 9 of the chapter entitled Of Perception in the First Edition ofthe Essay. Locke added the Molyneux discussion onto the end of Section 8 in theSecond Edition. An analysis of these two sections should help to explain preciselywhat general theoretical problem Locke is using the Molyneux question to illus-trate.

8. We are farther to consider concerning Perception, that the Ideas we receive by sensation, areoften, in grown People alterd by the Judgement, without our taking notice of it. When we setbefore our Eyes a round Globe, of any uniform colour, v.g. Gold, Alabaster, or Jet, tiscertain, that the Idea thereby imprinted in our Mind, is of a flat Circle variously shadowd,with several degrees of Light and Brightness coming to our Eyes. But we having by usebeen accustomed to perceive, what kind of appearance convex Bodies are wont to make inus; what alterations are made in the reflections of Light, by the difference of the sensibleFigures of Bodies, the Judgement presently, by an habitual custom, alters the Appearanceinto their Causes: So that from that, which truly is variety of shadow or colour, collectingthe Figure, it makes it pass for a mark of Figure, and frames to it self the perception of aconvex Figure and an uniform Colour; when the Idea we receive from thence, is only aPlain variously colourd, as is evident in Painting.

9. But this is not, I think, usual in any of our Ideas, but those received by Sight: BecauseSight, the most comprehensive of all our Senses, conveying to our Minds the Ideas of Lightand Colours, which are peculiar only to that Sense; and also the far different Ideas of Space,Figure, and Motion, the several Varieties whereof change the appearances of its properObject, viz. Light and Colours, we bring our selves by use, to judge of the one by the other.This in many cases, by a settled habit, in things whereof we have frequent experience, isperformed so constantly, and so quick, that we take that for the Perception of our Sensa-tion, which is an Idea formed by our Judgement; so that one, viz. that of Sensation, servesonly to excite the other, and is scarce taken notice of it self; as a Man who reads or hearswith attention and understanding, takes little notice of the Characters, or Sounds, but ofthe Ideas, that are excited in him by them.11

As its title suggests, the chapter in which these two sections are to be foundreflects on perception in general. Sections 8 and 9 discuss changes the judge-ment makes in some of our sensations. Nevertheless, the color-shape relation playsan important role here, since it is in regard to this relation that Locke explainswhy judgements are added to sensations.

The two sections take up the same problem, first in terms of a specific exampleand then more generally. We move from the description of a particular instance,here that of the vision of a sphere, to a description of what happens when we seeany convex shape in a single instant. Since we have learned by experience whatsort of mixture of color and shadow convex bodies produce in ourselves, we areable to move from the idea that is actually perceived (the idea of a flat Circle vari-ously shadowd) to the idea of its cause (alters the Appearance into their Causes). Wemake this jump thanks to a judgement that long habit has rendered unconscious.We thus believe to immediately receive the idea of a convex figure, when in fact

11 Essay, II, ix, 8-9.


the idea we immediately receive from sight is one of a flat figure. The idea of aconvex figure is simply the result of a judgement.12

In addition, Section 9 explains the reasons behind the phenomenon in ques-tion. Alterations in sensation effected by the judgement depend upon the par-ticular relation linking color and shape. Sight, Locke explains, gives us ideas ofcolor and light, as well as of space, shape, and motion. What is of interest is that inthe case of sight, and sight only, different shapes determine the appearance oflight and color in a uniformly colored object. Given this special connection be-tween shape and color, a change in the shape of an object whose color is uniform(like the golden, alabaster, and jet objects in Lockes own example) may lead to achange in the ideas of color that the object produces in us.13 Only experience canteach us to associate ideas of variously shadowd two-dimensional shapes withideas of three-dimensional figures of uniform color.

These two preceding sections deal more with the way in which shape modifiescolor rather than with the question of geometrical perspective. Locke never di-rectly discusses the two-dimensional figures that result from the projection of asolid body onto a plane. It would thus appear that his problem, when he discussesthe visual perception of the shapes of bodies, is not the two-dimensionality ofvisual ideas, but is rather one pertaining to variations in light and shade (aerial orcolor perspective). Indeed, throughout the Essay, Locke discusses neither visualperspective nor cases of illusion such as the square tower appearing to be roundwhen seen from a distance. It is thus not by chance that, when he speaks of light-shade variations, he uses the example of a sphere, which is precisely the onlyfigure whose visual appearance doesnt change upon a modification of viewpoint.

When discussing the relation between ideas of shape and color in Locke, it isthus necessary to distinguish between two different sorts of relation. First, ideas ofshape received by sight are the limits of color: it is color itself that collects theshape.14 Second, changes in the figure modify the color, because they add new

12 In what follows I use the term immediate in relation to ideasthere is no time-related conno-tation. The term will refer to an idea perceived by itself, and not through or by means of any otheridea. When I am referring to time I will use the word instantaneous or in an instant. For a discus-sion of the concept of immediacy and mediacy see M. Atherton, Berkeleys Revolution in Vision (Ithacaand London: Cornell University Press, 1990), 68-72, and R. Schwartz, Vision. Variations on Some BerkeleianThemes (Oxford, UK and Cambridge, MA: Blackwell, 1994) 13-7.

13 This would seem to entail a vicious circle. For if color is a secondary quality, an object may betermed of a uniform color only if it produces the idea of a uniform color in the subject. But in thecase of the circle and the sphere, we find ourselves faced with a troubling case in which an object ofuniform color does not appear as such. This is not an instance of an illusion depending upon theconditions under which the object was observed (for example, when we observe a white object throughred glasses), because any concave object of uniform color will appear with specific variations in itscolor. To avoid defining the uniformity of a color independently of its appearance, Locke uses theexample of a sphere whose respective compositions are universally recognized to be of uniform color:a round globe, of any uniform colour, v.g. Gold, Alabaster, Jet . . .

14 Essay, II, ix, 8: that, which truly is variety of shadow or colour, collecting the figure; Essay, II,xiii, 2: I have showed above, c.4. that we get the Idea of Space, both by our Sight, and Touch; which Ithink, is so evident, that it would be as needless, to go to prove, that Men perceive, by their Sight, adistance between Bodies of different Colours, or between the Parts of the same Body; as that they seeColours themselves: Nor it is less obvious, that they can do so in the dark by Feeling and Touch; J.Locke, Elements of Natural Philosophy, in Works, 10 vols. (London: T. Tegg, W. Sharpe, 1823; reprintedAalen: Scientia Verlag, 1963), vol. III, 325: Besides colour, we are supposed to see figure; but, in truth,that which we perceive when we see figure, as perceivable by sight, is nothing but the termination of


light and shade to the colors of the shapes we see. These two relations linkingcolor and shape are obviously of different orders. The first is a necessary connec-tion: for sight, ideas of shape without ideas of colorwith their specific limitsare impossible. The second is a contingent relation: it is quite possible to conceiveof or imagine a universe in which light arrives at the same intensity from all direc-tions. In this universe, there would be no shadows, changes in shape would notchange the appearance of colors, and the circle and sphere would appear as hav-ing exactly the same colors. Modification to the idea of color through variation inshape is thus contingent, and this contingent structure of variation is preciselywhat we must learn by experience.

Likewise in the case of our sense of touch, the shape of an object is perceivedas a function of the extremities of certain tactile qualities. However, changes inthe shape of the object perceived have no effect upon the tactile qualities thatallow us to perceive the shape in the first place.15 When we discover a shape viaour sense of touch, there is neither light nor shade. Thus judgement does notplay a role in the perception of shape via the tactile qualities of an object. This iswhy it is only in the case of changes in color caused by variations in shape thatLocke refers to experience and learning (But this is not, I think, usual in any ofour Ideas, but those received by Sight) through which we construct inferencesthat will take us from the idea immediately produced by sensation (the idea of avariously shaded circle, for example)16 to the idea of its cause (the idea of a sphereof uniform color).

The distinction I have drawn regarding the double relation between color andfigure also promotes an understanding of what distinguishes Locke from certainpassages in Berkeley concerning the application of the linguistic metaphor andthe concept of mark to visual perception. In the Lockean model described here,the sign is a pair of ideas (that of a circle and that of a non-uniform color), andthe meaning is another pair of ideas representing a sphere and a uniform color.Given that any changing of the color by the shape is contingent and arbitrary, it isonly experience that can teach us firstly how shape can change the idea of color,and secondly how to link one pair of ideas to the other. It would therefore be fairto say that learning to deal with the figural meaning of a shadowy circle as thesign of a sphere is quite similar to learning a language. Lockes linguistic meta-phor applies then only when ideas of two-dimensional shapes of non-uniform

colour. This claim is apparently contradicted at the beginning of Essay, II, xxiii, 11: Had we Sensesacute enough to discern the minute particles of Bodies, and the real Constitution on which theirsensible Qualities depend, I doubt not but they would produce quite different Ideas in us; and thatwhich is now the yellow Colour of Gold, would then disappear, and instead of it we should see anadmirable Texture of parts of a certain Size and structure. However, in the remainder of the section(as in the following one) Locke explains his first claim, and whenever he refers to ideas of shape asperceived by sight, they are accompanied by some ideas of color.

15 For example, if we discover that the square perceived instantaneously by our hand is actuallyone of the faces of a cube, we modify our idea of the shape perceived, but not that of the tactualqualities that allowed us to discover the shape.

16 The idea of a circle whose color is non-uniform is neither a fiction nor a retinal image. Thecircle is the effective content of the idea of sensation. It is necessary, however, to engage in a certainintrospective effort in order to recognize it as such, since one must stop the habitual, quasi-automaticpassage from the idea of the circle to the idea of the sphere. We will return to this question when wetake up Section 6 on The Problem of Unconscious Judgements.


color are taken as signs for ideas of three-dimensional figures of uniform color, asin the case of the circle and the sphere. Nevertheless, Lockes idea of a circle doesnot result from any judgement: it is a simple idea of sensation, so no linguisticmetaphor can be applied to Lockes account of the perception of the idea of acircle. Ideas of shape received by sight require that some difference in color beseen, although it would be inexact to say that ideas of color are the sign of ideas ofshape. Color shows, or as it were draws, shape but it is not the sign of shape.

In contrast with Berkeley then, Locke would not accept the use of a metaphoror concept such as mark for this sort of relation. In Berkeley, this metaphor ispervasive, and ideas such as extension, shape, and the like are not ideas perceived,strictly speaking, by the sight. Nevertheless, ideas of spatial properties can be sug-gested by ideas from the sight in the same way that words heard can suggest ideasof the objects they signify.17

In spite of these differences, it is worth noting that one discovers in Lockesconcept of the mark, and in the linguistic metaphor, a point which will figureimportantly in Berkeleys philosophy. What is at stake here is the existence ofarbitrary relations of covariation between certain groups of ideas of sensation andideas of other sorts. This type of covariation exists between ideas of certain flatfigures variously colored (the particular arrangement of shadows on the surfaceof the circle) and ideas of three-dimensional shapes of uniform color (the idea ofa uniformly colored sphere).

2 . S E E I N G T W O - D I M E N S I O N A L A N D T H R E E - D I M E N S I O N A LS H A P E S

The existence of a judgement which takes us from the idea of a circle to the ideaof a sphere gives rise to two questions: (1) Does Locke presume the judgement inquestion to bring about associations with ideas of tridimensional figures perceivedby touch? (2) Does Locke presume such a judgement to come about only undercertain particular situations (e.g., the perception of a sphere set before our eyes),or is it always necessary for the vision of solid figures? The two questions are con-nected. I believe Locke considers it possible for sight to receive ideas of three-dimensional shapes without having recourse to a judgement. The consequenceof this is that the judgement in the example of the circle and the sphere does notnecessarily require an association with the ideas of touch. I shall try to show thesepoints while sticking to the text in the First Edition of the Essay.

The problem is more or less the following. Sections 8 and 9 of the First Editiondo not contain any explicit reference to the sense of touch and its relation to

17 I refer here to those passages in the NTV where Berkeley maintains that we do not actually getour ideas of shape from sight. Through sight we perceive only light and color. See, for example, NTV,130: . . . in a strict sense I see nothing but light and colours, with their several shades and variations. . . It must be owned that by the mediation of light and colours other far different ideas are suggestedto my mind: but so they are by hearing, which beside sounds which are peculiar to that sense, doth bytheir mediation suggest not only space, figure, and motion, but also all other ideas whatsoever thatcan be signified by words. Cf. also NTV, 129, 151, 156, 157, 158 and Alciphron or the Minute Philosopher,in The Works of George Berkeley Bishop of Cloyne, vol. 3, IV, 10. In fact, the relation between light and color,on the one hand, and spatial qualities, on the other, is far more complicated, because between the twoa process of construction takes place. Cf. M. Atherton, Lessons Learned from the Theory of Vision Vindi-cated, text currently in press.


vision. Judgements, says Locke, are added to ideas of sensation only in visual per-ception.18 One might, however, interpret the passage concerning the knowledgeof what kind of appearance convex bodies are wont to make in us; what alter-ations are made in the reflections of Light, by the difference of the sensible Fig-ures of Bodies as an implicit reference to the sense of touch. Two possiblitiespresent themselves before us: either sight cannot have immediate access to solidfigures, in which case the use here consists of associations between ideas of sightand those of touch; or, sight too can gain access to solid figures, and the use couldbe interpreted in the broad sense of experience without necessarily involving thetactile experience. If the second possibility is the correct one, then Sections 8 and9 of the First Edition deal exclusively with the complexity of the visual perceptionof the figure. There will therefore be no room, in these paragraphs, to speak ofthe relation between visual and tactile ideas of figure. The Molyneux questionwould then be placed in a context that, originally, has nothing to do with theconnection between the different senses. I shall thus endeavour to demonstratethe possibility for the vision of three-dimensional figures.

A first argument exists that could support the opinion that sight, just as touch,can perceive three-dimensional figures. It is founded upon the kind of hierarchyof the senses put forward by Locke. In Chapter V, Of Simple Ideas of DiversSenses, figure is classed as a simple idea of sensation that can be perceived byboth sight and touch.19 In the chapter on the simple modes of space, the fact thatthe two senses can perceive shapes returns:

There is another Modification of this Idea, which is nothing but the Relation which theParts of the Termination of Extension, or circumscribed Space have amongst themselves.This the Touch discovers in sensible Bodies, whose Extremities come within our reach; andthe Eye takes both from Bodies and Colours, whose Boundaries are within its view: Whereobserving how the extremities terminate . . . by considering these as they relate to oneanother, in all Parts of Extremities, of any Body or Space, it has that Idea we call Figure,which affords to the Mind infinite Variety.20

We shall examine this quote in detail later. What interests us here is that touchis said to receive the ideas of figure from sensible bodies within its reach, whilesight receives these sort of ideas not only from sensible bodies, but also fromcolors (both from Bodies and Colours). In addition, the extremities that sight is ob-serving and considering in order to discover ideas of figure can belong both tobodies and to space. Sight, then, takes two sorts of shapes (shapes of bodies andof spaces) whereas touch only has access to shapes of bodies.

This difference between touch and sight helps explain the passage from Sec-tion 8 quoted above, where sight is said to be the most comprehensive of all ourSenses. Sight is the most comprehensive sense because it has access to figuresthat the sense of touch cannot reach. This is also the reason why Locke gives prideof place to painting over the other arts, with sculpture in second place. In paint-

18 Essay, II, ix, 9.19 The ideas we get by more than one sense, are of Space, or Extension, Figure, Rest and Motion: For

these make perceivable impressions, both on the Eyes and Touch; and we can receive and convey intoour Minds the ideas of the Extension, Figure, Motion and Rest of Bodies, both by seeing and feeling.Essay, II, v.

20 Essay, II, xiii, 5.


ing, one has access to shapes that our sense of touch cannot perceive.21 What thecomparison between painting and sculpture shows us is that the comprehensive-ness of a given sense doesnt depend upon the number or the importance of thequalities it perceives. If this were the case, touchs ability to perceive solidity, whichis the essential quality of any body, would probably give it precedence over sight.22

Instead, the comprehensiveness of a given sense may be measured by its abilityto detect qualities that may be perceived by more than one sense, like figure,space, or movement.23

This claim for the primacy of sight over touch is important, since it reveals thedistance between Locke and Berkeley on the issue. In the New Theory of Vision,Berkeley claims that only touch can authentically transmit spatial ideas, while sightreally only perceives light and color.24 The importance Locke places on sight inthis hierarchy has not been recognized, and I believe the reason for this is to befound in the persistence of interpretations of Locke based on Berkeleian catego-ries. Thus, the emphasis in the commentaries on Lockes philosophy of percep-tion is on what sight must borrow from touch when it perceives figures. In general,it is presumed that sight can perceive only two-dimensional shapes, while touchhas access to three-dimensional figures as well. I, on the contrary, would suggestwe take the claims for sights pre-eminence over touch seriously, and entertain thenotion that sight can not only perceive the shapes of bodies, but also that thereare more shapes perceivable by sight and inaccessible to touch than vice-versa. Theprimacy of sight over touch in Locke is a first step toward the thesis of the possibil-ity of the visual perception of three-dimensional shapes. If there are no ideas ofshape perceived by touch that cannot in theory also be perceived by sight, then itfollows that if touch has access to three-dimensional shapes, so too should sight.

A second argument in favour of the visibility of three-dimensional figures isbased upon the definition of the figure. In Book II, xiii, 5, figure is defined as amode of space. In Section 2 of the same chapter, Locke writes that we receive theidea of space via sight and via touch, and that this fact is so obvious that it would beidle to try to prove it. In what follows, Locke defines distance as space considered

21 Thus the Word Statue may be explained to a blind Man by other words, when Picture cannot,his Senses having given him the Idea of Figure, but not of colours, which therefore Words cannotexcite in him. This gaind the Prize to the Painter, against the Statuary; each of which contending forthe excellency of his Art, and the statuary bragging, that his was to be preferred, because it reachedfarther, and even those who had lost their Eyes, could yet perceive the excellency of it. The Painteragreed to refer himself to the judgement of a blind Man; who being brought where there was a statuemade by the one, and a Picture drawn by the other; he was first led to the Statue, in which he tracedwith his Hands, all the Lineaments of the Face and Body; and with great admiration applauded theSkill of the work-man. But being led to the Picture, and having his Hands laid upon it, was told, Thatnow he touched the Head, and then the Forehead, Eyes, Nose, etc. as his Hand moved over the Partsof the Picture on the Cloth, without finding any the least distinction: Whereupon he cried out, thatcertainly that must needs be a very admirable and divine piece of Workmanship, which could repre-sent to them all those Parts, where he could neither feel nor perceive any thing (Essay, III, iv, 12).

22 Essay, II, iv, 1: This [solidity] of all other, seems the Idea most intimately connected with, andessential to Body, so as no where else to be found or imagind, but only in matter . . .

23 Aristotle accepts the same hierarchy among the senses (De Sensu, 1 437a 5-9). See also Platon,Time 47 a-b; Descartes, Dioptrique, Disc. I, in Ch. Adam & P. Tannery, eds. uvres philosophique, 11 vols.(Paris: Vrin, 1964-1971), vol. VI, 81 and Malebranche, Recherche de la verit, in uvres compltes (Paris:Vrin, 1962), Tome 1, Livre I, ch. VI, 79.

24 See n. 17 above.


exclusively as length between two objects (barely in length between any two Beings),and capacity as space considered in terms of length, width, and depth.25 Themodes of space are thus divided into one-dimensional (distance) and three-di-mensional (capacity). No explicit definition is provided for two-dimensional spaceas a particular mode. The idea of figure defined in Book II, xiii, 5, as a circum-scription of three-dimensional space is therefore an idea of three-dimensionalfigure. We may momentarily set aside any question concerning the identity ordifference between the ideas of shapes perceived by both sight and touch: what Iam concerned with here is that in the cases mentioned in the definition of figure,both sight and touch have ideas of three-dimensional shapes.

The definition of the ideas of figure refers to particular ideas of space insofaras they are perceived by sight and touch. In the case of sight, the eye is said totake ideas of figure in two phases: first, by observing how the extremities of thingsor colors touch up against each other, and second, by considering the limits of allthe parts of a given object. It is important to realize that this observing and consid-ering does not involve a judgement. For Locke, sight (the eye) receives the ideasof figures from bodies and space, and where it is possible to observe and considerall the parts of an object (in all Parts of Extremities, of any Body or Space), itreceives ideas of three-dimensional figures. Three-dimensional figures are in factideas of sensation that can be received by sight and touch, even when the act ofperception, in the case of sight, entails observation and consideration by the subject.

To state that observation and consideration are necessary for a subject to seethree-dimensional figures does not, in my opinion, imply that there is a judge-ment. For this very operation of considering has already been referred to in orderto describe the attention necessary on the subjects part if clear and distinct ideasof sensation and reflection are to be had.

. . . For, though he that contemplates the Operations of his Mind, cannot but have plainand clear Ideas of them; yet unless he turn his Thoughts that way, and considers themattentively, he will no more have clear and distinct Ideas of all the Operations of his Mind, andall that may be observed therein, than he will have all the particular Ideas of any Land-scape, or of the Parts and Motions of a Clock, who will not turn his Eyes to it, and withattention heed all the Parts of it. The Picture, or Clock may be so placed, that they maycome in his way every day; but yet he will have but a confused Idea of all the Parts they aremade up of, till he applies himself with attention, to consider them each in particular.26

The attention necessary to move from confused ideas of the different parts ofa landscape or of a clock to clear ideas of them is not the same thing as a judge-ment. There are then two sorts of ideas of sensation: first, the clear ideas resultingfrom attentive observation and consideration by the subject, and second, con-fused ideas resulting from hasty observation of the object at hand. There is nodifference in the immediacy of these two sorts of simple idea: both are simpleideas of sensation. The difference concerns only the extent to which the ideas

25 The concept of capacity will later be divided into extension (which is capacity occupied by a body)and space (which is capacity when it is unoccupied).

26 Essay, II, i, 7.


contents are clear and distinct.27 This process in which ideas are made clear isnecessary for ideas of figure as much as for ideas of color, in my opinion. Bothrequire a certain attentiveness on the subjects part in order to become clear.28

Later, the understandings discernment will make these ideas not just clear, butalso distinct.29

This sensorial manner of understanding the attentive observation and con-sideration involved when receiving a clear and distinct idea is compatible with animportant characteristic of simple ideas: that the understanding receives thempassively.30 When the understanding receives simple ideas, it is, as Locke says, likea mirror that cannot refuse, alter, or erase the images that the objects beforewhich the mirror is placed produce in the mirror.31 This metaphor is used toshow that the understanding isnt free to create its own simple ideas. These limits,metaphorically imposed upon the understandings liberty by Locke, should notbe taken to mean that simple ideas, like the images reflected in a mirror, comeexclusively from the action of light or other physical processes on our sense or-gans. These limits are therefore compatible with the need for attentive consider-ation of the content of a simple idea.32

I believe at this point to have the elements required to answer the two ques-tions set at the beginning of this section. Given that it is possible for sight toreceive ideas of three-dimensional figures without having recourse to a judge-ment, then clearly the judgement that takes us from the idea of a variously shadedcircle to the idea of a uniformly colored sphere does not occur in all cases offigure perception. Moreover, given that there are ideas of convex figures that areimmediately perceived by sight, the judgement does not necessarily involve a move-ment from ideas of sight to ideas of touch.

3 . S E E I N G T H R E E - D I M E N S I O N A L O B J E C T S

Locke does not explain precisely how it is possible to see three-dimensional ob-jects. To see how this works, then, we will have to follow a few vague hints. In theEpistle to the Reader, and in a few other places, there is a metaphor whereLocke refers to different perspectives on the same object. He writes,

Some Objects had need be turned on every side; and when the Notion is new, as I confesssome of these are to me; or out of the ordinary Road, as I suspect they will appear to others,tis not one simple view of it, that will gain it admittance into every Understanding.33

27 Locke defines a clear idea as follows: . . . In like manner, our simple Ideas are clear, when theyare such as the Objects themselves, from whence they are taken, did or might, in a well-orderedSensation or Perception, present them (Essay, II, xxix, 2). On the genesis of this definition, see M.Ayers, The Foundation of Knowledge and the Logic of Substance: The Structure of Lockes GeneralPhilosophy, in Rogers, ed., Lockes Philosophy, 49-73, 52. Cf. also Essay, IV, xiii, 2: There is also anotherthing in a Mans Power, and that is, though he turns his Eyes sometimes towards an Object, yet he maychoose whether he will curiously survey it, and with an intent application, endeavor to observe accu-rately all that is visible in it. This passage had been reworked in the second edition.

28 Essay, II, xxix, 8.29 Essay, II, xxix, 4; II, xi, 1-3.30 Essay, II, i, 25.31 Essay, II, i, 25; II, xii, 1.32 Essay, II, ix, 3-4.33 Essay, Epistle to the Reader, 8. Cf. also II, xix, 1 and 3; II, xxi, 47.


A few other hints about how we see three-dimensional objects come up in thedefinition of figure in Section 5 of Chapter xiii. The process of figure perceptioncan be divided into two phases. First, observing a series of edges of color. Sec-ond, considering how they relate to each other, and synthesizing the differentedges into a unique idea of figure.34

Locke does not explain the mechanisms of this process of observation andconsideration, but such an explanation is not within the general purview of theEssay, which tends to leave out any talk of the mechanisms of perception.35 Thatsaid, in An Examination of P. Malebranches Opinion, Locke in one passage stressesthe fact that what we habitually see does not correspond to what one immobileeye can see. The visual stimulus is then, for Locke, the stimulus received by twomoving eyes. This shows that he conceives the structure of retinal informationdifferently from the punctual conception put forth by Berkeley.36

In my model, the material impressions of sight in Locke are not (instanta-neous) retinal images, but rather a succession of images. One is struck by themodernity of this conception of visual stimulus and the content of the visual idea.Sight and touch appear then to fit into the same general model, one in whichperception needs time and movement to get to a clear and distinct idea of form.One might therefore conclude that ideas of figure are the result of a process thattakes time, at least in most cases. If this is true, then ideas of figure are nothing atall like a painting or a photograph representing only one point of view. Rather,they would be more like certain ways of representing volumes in architecture, oreven better, certain Flemish paintings where several points of view are representedat once.37

A look at the simple idea of movement may help us explain the temporality ofthe simple idea of figure. Locke defines a simple idea as one which is each initself uncompounded, contains in it nothing but one uniform Appearance, or Con-

34 Here the distinction between impressions, on one hand, and sensations and ideas, on theother, follows that given by Locke. Cf., among others, Essay, II, ix, 3-4.

35 Essay, I, i, 2: I shall not at present meddle with the Physical Consideration of the Mind.36 Locke, An Examination of P. Malebranches Opinion of seeing all things in God, in Works (1823), vol.

IX, Sect. 9: Nor is it true, that though the eye be in any one place, yet that the sight is performed inone point, i.e. that the rays that bring those visible species do all meet in a point; for they cause theirdistinct sensations, by striking on distinct parts of the retina, as is plain in optics; and the figure theypaint there must be of some considerable bigness, since it takes up on the retina an area whose diam-eter is at least thirty seconds of a circle, whereof the circumference of it in the retina, and the centresomewhere in the crystalline; as a little skill in optics will manifest to anyone that considers, that feweyes can perceive an object less than thirty minutes of a circle, whereof the eye is the centre. And hethat will but reflect on that seeming odd experiment of seeing only the two outwards ones of three bitsof paper stuck up against a wall, at about half a foot, or a foot one from another, without seeing themiddle one at all, whilst his eye remains fixed in the same posture, must confess that vision is not madein a point, when it is plain, that looking with one eye there is always a part between the extremes of thearea that we see, which is not seen at the same time that we perceive the extremes of it; though thelooking with two eyes, or the quick turning of the axis of the eye to the part we would distinctly view,when we look but with one, does not let us take notice of it. Berkeleys opposed way of seeing thiscomes through, for example, when he uses Molyneuxs argument on the unique projection of dis-tance on the retina to show that distance is not an idea immediately available to sight. Cf. NTV, 2 and11.

37 Cf. S. Alpers, The Art of Describing (Chicago: University of Chicago Press, 1983), 68-70, 80.


ception in the Mind, and is not distinguishable into different Ideas.38 Now anidea of movement, although it includes relations among the various spatio-tem-poral orders, is not a complex idea of relation: it is a simple idea with a uniformcontent. The temporal dimension apparently contained within these ideas oper-ates only on the level of the material impression. It would seem that for Locke,the temporal dimension of a material impression (necessary for the reception ofideas of three-dimensional figures or movement) is not the content of an idea.Instead, it would appear to vanish once the different parts perceived have beensynthesized.39 This diachronicity in impressions of sight short-circuits the opposi-tions between instantaneous visual sensations and diachronic tactile sensationsadvanced by Lotze and von Senden, among others.40 For Locke, visual and tactilesensation share the same temporal dimension.

The importance given by Locke to sight in his hierarchy of the senses, takenwith the description of the visual perception of figures in the chapter on space,supports the hypothesis that sight actually has access to three-dimensional fig-ures. Moreover, the Examinations complex conception of visual stimulus, and therole given to the act of considering in the description of seeing figures in Book II,xiii, 5, suggests a diachronic model of perception. Nowhere in Locke, it seems tome, do we find elements supporting the hypothesiswhich Berkeley presentsexplicitlythat sight has indirect access, via touch, to three-dimensional figures,41

nor do we have a clear assertion that touch gains easier access to ideas of three-dimensional figures than sight.

4 . A N A L T E R N A T I V E V I E W : B O L T O N SI N T E R P R E T A T I O N O F T H E M O L Y N E U X P R O B L E M

According to my interpretation, there are ideas of three-dimensional figures im-mediately received by sight. Given that Locke does not refer to a specific differ-ence between ideas of figure perceived by sight and those perceived by touch,one can suppose that these ideas are not necessarily specifically different fromeach other. Here lies the difference between my interpretation and the standardone given to the Molyneux problem.

However, there is another way to oppose the standard interpretation and todeny a specific difference between the ideas of figure of sight and of touch. MarthaBolton, in a recent article entitled The Real Molyneux Question and the Basis ofLockes Answer, has claimed that in Locke, figures are never the immediate objects

38 Essay, II, ii, 1. Ayers contrasts the phenomenal criterion of simplicity in Locke with the logicalcriterion of simplicity in Descartes. Cf. M. Ayers, Locke, vol. 1, 48.

39 For a discussion of a similar problem concerning the temporal dimensions of ideas in Berkeley,see R. Glausers Berkeleys Theory of Vision and the Structure of Mediate Perception, currentlybeing published.

40 Cf., for example, M. von Senden, Space and Sight, trans. by P. Heath (London: Methuen, 1960),285-6. This position is dicussed by G. Evans in his posthumous article Molyneux Question, in Col-lected Papers (Oxford: Clarendon Press, 1985), 364-99, in particular 365-8.

41 In the Elements of Natural Philosophy, for instance, figure does not feature among the ideas thatcan be perceived by touch, while it is included among the ideas perceivable by sight. J. Locke, Elementsof Natural Philosophy, 327: by this sense the tangible qualities of bodies are discerned; as hard, soft,smooth, rough, dry, wet, clammy, and the like. But the most considerable of the qualities that areperceived by this sense, are heat and cold.


of sight, but instead depend upon our seeing the only ideas truly immediatelyavailable to sight, i.e., ideas of light and color.42 For Bolton, Locke claimed en-tirely without restriction that we see figures by judging color and shading.43 Thereis, then, a difference in the visibility of color and figure: only color is visible in thestrictest sense of the term, while figure is always the result of a judgement. Itfollows from this reading that ideas of shape are not immediately available to oursight. As Bolton maintains that there are no ideas of figure perceived immediatelyby sight, it necessarily follows that there is no heterogeneity between the ideas offigure of sight and of touch.44 It is quite clear that my interpretation and that ofBolton are opposed: she claims that there are no ideas of figure perceived imme-diately by sight, whereas I maintain that sight can immediately receive even ideasof three-dimensional figures. I find Boltons article very stimulating, yet I remainunconvinced by her arguments.

Basing her argument exclusively on the passage where sight is said to perceivea variety of shadow or colour, collecting the figure, Bolton claims that, for Locke,sight does not have direct access to the figure of bodies. According to Bolton,another passage, discussed above, presents an even more radical thesis, namelythat all ideas of figure (which I take to mean not only ideas of figures of bodies)45

depend upon a judgement proceeding from ideas of shadows and colors. Thepassage is the following:

Sight, the most comprehensive of all our Senses, conveying to our Minds the Ideas of Lightand Colours, which are peculiar only to that Sense; and also the far different Ideas of Space,Figure, and Motion, the several Varieties whereof change the appearances of its properObject, viz. Light and Colours, we bring our selves by use, to judge of the one by theother.46

I, for one, am unable to see in what way this passage suggests that Locke main-tains that we see figures by judging color and shading. I believe that Boltonsproposition is contradicted by what Locke writes in precisely this very passage,namely that sight receives not only its own, exclusive ideas of light and color, but

42 Bolton, The Real Molyneux Question, 81. Cf. also Lievers, The Molyneux Problem, 408:The proper objects of the sense of sight are light and colors . . . These far different ideas of space,motion, and figure are also perceived by sight, but in an indirect way. Cf. also Vienne, Locke etlintentionnalit: Le problme de Molyneux, 671, 679.

43 Ibid., 81. Bolton understands this judgement as Locke does in Essay, IV, xiv, 4: . . . the puttingIdeas together, or separating them from one another in the Mind, when their certain Agreement orDisagreement is not perceived, but presumed to be so.

44 Ibid., 82.45 Ibid., 80: Further, it is not just bodily shapes that we learn to judge by variations in colour and

light.46 Essay, II, ix, 9. Bolton does not cite the whole of this passage and uses marks of omission

precisely in place of the expression, Sight, the most comprehensif of all our Senses; Bolton, op. cit.,80. This thesis is supposedly confirmed by Locke in Elements of Natural Philosophy: Besides colour, weare supposed to see figure; but, in truth, that which we perceive when we see figure, as perceivable bysight, is nothing but the termination of colour. J. Locke, Elements of Natural Philosophy, 365. Thisdefinition of figure is similar to the one given in the Essay, where Locke employs the classic definitionof figure as termination of extension. This in no way means that we cannot see the figure, given thatit refers to the figure as it is perceived by sight. The figures visibility is therefore presupposed. To useHumes terminology, it can be said that between ideas of color and those of figure, as far as they areperceived by sight, there is only a distinction of reason.


also receives ideas of space, figure, and movement which are common to the senseof touch.

A similar problem arises regarding a second proposition put forward by Boltonand which is parallel to the aforementioned one. According to this thesis, it isordinarily impossible to have the idea of the figure of a flat or a convex bodyunless it results from a judgement proceeding from the configuration of the lightsand colors perceived. The reason for this impossibility would be that prior to thejudgement, it cannot be known whether one is perceiving a flat body or a convexbody.47 Thus, when one looks at, for example, a sphere or a coin, sight immedi-ately receives an idea of a circle along with a certain configuration of shadow andlight. However, in order to have the idea of a spherical or cylindrical body (suchas a coin seen from the front), a judgement must proceed from the idea of a circleand from the configuration of shading and light.

I am ready to grant Bolton this point. However, her thesis then becomes moreradical as she goes on to add that even the vision of a bodys two-dimensionalcontours depends upon a judgement.48 This second thesis must obviously reckonwith Lockes assertion that when looking at a sphere placed before us, sight re-ceives an idea of a flat, variously shaded circle. Bolton suggests a non-literal read-ing of the expression idea of a flat circle as it is used here by Locke, and asks usto consider the idea of a flat circle as the idea of a simple configuration of lightand color:

[Locke] was struggling to describe a pattern of light and colour that has no reference tofigures in two- or three-dimensional space. As he put it elsewhere the circularity pertains,not to a surface, but to the termination of colour; and we can suppose that the idea isflat in that it specifies nothing about spatial relations among parts of a surface.49

Bolton denieswith good reasonthat this idea of a flat circle is the descrip-tion of a retinal image, but she also denies that this idea is an idea of figure.Indeed, she suggests a reading where the idea of a flat circle is the idea of a con-figuration of shading and light, and calls this reading wholly non-spatial, asthough an idea of a circle, considered as an idea of a pattern of light and color,was not an idea of figure. For my part, I am unable to comprehend how an idea ofa circle, considered as an idea of a pattern of light and color, cannot be an idea offigure. Furthermore, I cannot see how Bolton can take into consideration thenumerous instances in the Essay where Locke maintains that figure is a simpleidea as perceptible by sight as it is by touch, and that the Extension, Figure,Number, and Motion of Bodies of an observable bigness, may be perceived at adistance by the sight . . . I am ready to grant Bolton that a judgement is necessaryin order to consider an idea of a plane figure plus a certain configuration ofshading and light as the sign of a solid figure. However, I do not take this to meanthat the only immediate ideas of sight are those of light and color.

47 Cf. Bolton, op. cit., 81: Locke surely did not mean that we receive, without judgement, theidea of a circular body with plane surface (such as a coin).

48 Cf. Ibid.: . . . even vision of the two-dimensional outlines of bodies is achieved by judgement.49 Cf. Ibid., 82. She describes this way of interpreting the idea of the flat circle as a . . . wholly non-

spatial reading . . .


50 Cf. Essay, ix, 8.

I believe part of this problem depends on a simplification of the terms in-volved in the judgement which takes us from the idea of a circle to the idea of asphere. As mentioned earlier, in this example Locke describes the way in which ajudgement enables us to move from a pair of ideas, composed of an idea of acircle and an idea of non-uniform color, to another pair of ideas composed thistime of an idea of a sphere and an idea of uniform color. The transition is notsimply from an idea of a circle to an idea of a sphere, but rather from an idea of acircle with certain chromatic characteristics to an idea of a sphere with otherchromatic characteristics. Thus, getting back to the example of Locke, the idea ofuniform color, just as that of the sphere, depends on the creative capacities ofjudgement, whereas Bolton considers the judgement to affect only the percep-tion of ideas of figure. The fact that the judgement also includes ideas of colorimplies that if one asserts that all ideas of figure necessarily depend on a judge-ment, then it must also be asserted that all ideas of color depend on a judgement.

5 . T H E M O L Y N E U X P R O B L E M

There appears to be a sort of tension between the possibility of the vision of three-dimensional figures and what Locke writes concerning the perception of a sphere.If indeed it is possible for sight to receive ideas of a sphere, why then does Lockestate that when looking at a sphere placed before us, what our sight receives inreality is an idea of a circle? To resolve this tension, it is sufficient to presume thatthe two cases describe two different perceptive situations. According to this hy-pothesis, the case of the circle and the sphere would describe a perceptive situa-tion that excludes any movement from either the subject or the object, whereasthe case of the vision of three-dimensional figures necessarily implies a relativemovement between subject and object. The response to the Molyneux problemcan be explained in the same way.

We have seen that Locke approves of the response suggested by Molyneux tohis own problem. According to this response, the man cured of his blindness isnot able to recognise or name the cube and the sphere because he has not yetlearned to associate a certain semblance of touch with a semblance of sight. Lockesupports this response, while specifying his particular reasons for the negativereply in the following way:

I agree with this thinking Gent. whom I am proud to call my Friend, in his answer to this hisProblem; and am of opinion, that the Blind Man, at first sight, would not be able withcertainty to say, which was the Globe, which the Cube, whilst he only saw them: though hecould unerringly name them by his touch, and certainly distinguish them by the differenceof their Figures felt.50

Locke thus adds two important specifications: he writes that the cured blind mancannot recognise and name the two figures with certainty nor at first sight. Ifthe blind man is unable to recognise and to name the cube and the sphere withcertainty, this signifies that he will at least be able to correctly estimate the figuresand their names. It would therefore appear that any hypothesis concerning aradical heterogeneity between figures of sight and touch is without foundation.


Even richer in consequence is the use of the term at first sight. It suggeststhat if the cured blind man was given the opportunity to observe the two objects atlength, he would be capable of distinguishing and naming them. This can beinterpreted in two ways. We saw earlier (in Section 2 of this paper) that in order tohave ideas that are clear and distinct, careful consideration is necessary. Thoseideas perceived by the blind man at first sight will necessarily be unclear andconfused. This being the case, it is obvious that the blind man will not be able torecognise their conformity with any other sort of idea with certainty. There re-mains another limitation arising from the phrase at first sight, notably that theblind man can only observe the two objects from one point of view. This limita-tion suggests that if the cured blind man could both observe the objects from allsides and consider the manner in which the extremities touch up against eachother, then he could recognise and name the cube and the sphere. The possibleideas of figure perceived at first sight by the cured blind man are thus incom-plete. Three-dimensional figures do not come across as instantly visible.

Now, if one wonders what exactly the experience, improvement and acquirednotions are that Molyneuxs subject will use to get from the idea of the circle tothe idea of the cube, one might think, recalling Sections 2 and 3 of this paper,that there does not need to be any association between the ideas of sight andthose of touch. In fact, neither Molyneux nor Locke makes any reference to theneed for association between the two senses. Molyneux writes in his Responsethat the man, having gotten back his sight but before having touched the twoobjects, cannot know that what affects his touch so or so, must affect his sight so or so; Orthat a protuberant angle in the Cube, that pressed his hand unequally, shall appear to hiseye, as it does in the Cube.51 What needs to be learned, then, is how different shapesappear to the sight. Our man already knows that when he touches it, the angle ofa cube seems to be something that pressed his hand unequally. What he stillneeds to learn is how it seems to his sight. During these experiences he will learnthat a certain structure of shadow and light corresponds to an angle or to a con-vexity, and that angles and convexities change the color of the object. Our manwill have to learn to decipher the patterns of light and color because, as we haveseen, the changes in color caused by different shapes relate exclusively to sight:there is nothing similar as regards our sense of touch. The experience required tolearn about these correspondances can come from kinesthesia, from seeing anobject from several points of view, or even from seeing an object that has had lightshined on it from moving light sources.52 Reference to the sense of touch serves

51 Essay, II, ix, 8.52 Throughout the eighteenth century, what is peculiar to sight had not yet been identified with

the retinal information. Thus for Descartes, Malebranche, and Molyneux, what is peculiar to the senseof sight consists not only of the information contained in the retinal images, but also the sensationsderiving from the movement of the ocular muscles (cf., e.g., Descartes, Dioptrique, AT, VI, 137: Lavision de la distance [dpend ] . . . premirement de la figure du corps de lil . . . Nous connaissons,en second lieu, la distance par le rapport quont les deux yeux lun lautre; cf. Malebranche, Recher-che de la verit, Tome 1, Livre I, Ch. IX, III, where the first two of the six means for the vision of distanceare the size of the visual angle, and the position and shape of the eye, respectively; cf. Molyneux,Dioptrica Nova, 113: But as to nigh Objects, to whose distance is perceived by the turn of the eyes . . .and 114). There is reason to believe that for Locke, too, visual data does not coincide with retinalinformation but rather with all that concerns the eye in general. Berkeley classifies the kinaesthetic


only to illustrate what the man does not yet know, but might theoretically learn inthe process of an exclusively visual experience. Seen this way, Molyneuxs prob-lem concerns the specificity of the process of the visual perception of figure morethan it does the relation between the senses.

In my interpretation, Locke uses the example of the circle and the sphere, aswell as the Molyneux Question, solely to explain a particular sort of vision of athree-dimensional object, and not for a general explanation of seeing figures andspace. The particular sort of vision in question is one where a three-dimensionalobject is seen instantaneously and without any movement by either the subject orthe object. In this particular case, it is true that we receive the idea of a circle, andthat to get to the idea of a sphere a judgement will be necessary. However, insituations where one has several points of view on an object, I believe Locke con-siders it possible to receive the idea of three-dimensional shape.53

Lockes negative reply to Molyneux is therefore motivated by the confusedand incomplete nature of the idea of figure received at first sight by Molyneuxsman. The idea is confused because he will need to furnish the attention and con-sideration necessary in order to have a clear and distinct idea of the two-dimen-sional shape. And the idea is incomplete because the man will need time andmovement to see the three-dimensional figure.

6 . T H E P R O B L E M O F U N C O N S C I O U S J U D G E M E N T S

It remains to resolve one last problem engendered by Lockes response toMolyneux. In Locke, consciousness is a necessary condition for thinking and hav-ing ideas.54 That said, in his response to Molyneux, Locke has recourse to judge-ments by which we move from the idea of a circle to the idea of a sphere, and weare not conscious of these judgements. How can these be judgements, given thatwe cannot think unconsciously? Condillac attacked Locke on precisely this point.55

I think it is possible to defend Locke here, using first one of Lockes own argu-ments justifying the necessity of consciousness for thought, and then an analysisof the type of non-consciousness we are dealing with.

In Section 15 of the chapter on ideas and their origins, Locke bases the theoryof the necessity of consciousness for thought on utility:56 if we cannot remember

sensations among the tactile sensations, but this is not explicitly stated in Locke. One might supposethat Locke would allow kinaesthetic sensations to be admitted into visual sensations.

53 I think Locke is talking about the same particular case in which we instantaneously see a three-dimensional object in Section 12 of An Examination of P. Malebranches Opinion: In the next place,where he says, that when we look on a cube we see all its sides equal. This I think is a mistake and Ihave in another place shown, how the idea we have from a regular solid, is not the true idea of thatsolid, but such as one as by custom (as the name of it does) serves to excite our judgement to formsuch as one. It should be noted that here, Locke does not identify the true idea of that solid withthe idea perceived by the sense of touch.

54 Essay, II, i, 10: I do not say there is no Soul in a Man, because he is not sensible of it in his sleep;But I do say, he cannot think at any time waking or sleeping, without being sensible of it. Our beingsensible of it is not necessary to any thing, but to our thoughts.

55 Cf. E. B. de Condillac, Essai sur lorigine des connaissances humaines (Paris: Alive, 1998), Ch. XI,Sect. 6, 4.

56 Essay, II, i, 15: If it has no memory of its own Thoughts; if it cannot lay them up for its use andbe able to recall them upon occasion; if it cannot reflect upon what is past, and make use of its formerexperiences, reasonings and contemplations, to what purpose does it think?


our thoughts or use them in future experiences, then why think at all? However,when it comes to the judgements that take us from the idea of a circle to the ideaof a sphere, the situation is different because the unconsciousness of the judge-ment is useful: it allows us to make extremely quick judgements, much faster thanif they were conscious. For Locke, the variety and rapidity of sensations are thesigns of sensations level of development.57 If the criterion of usefulness is ac-cepted, it thus becomes possible to have unconscious judgements.

In addition, Locke says that the judgements that allow us to construct the ideaof a sphere of uniform color from that of the variously shaded circle are madeunconscious by force of habit. These judgements are not necessarily unconscious.They are only unconscious in many cases and in things whereof we have fre-quent experience.58 This would imply that in less habitual situations, these judge-ments might be conscious. One can become aware of these judgements, for ex-ample, when observing the representation of a sphere in a painting (as is evidentin painting). Looking at a painting is not a habitual situation, and here we be-come conscious of the inference leading from the circle to the sphere.

As Locke himself says, we judge unconsciously in the same way that we blinkour eyes unconsciously,59 in the same way that we unconsciously link the sounds ofa speech and its words. Most of the time, we are not conscious of the movementsof our eyelids, or of the sounds we hear, but theoretically we can become con-scious of these things. Locke writes these sections, then, in order to bring outsomething that habit and prejudice have kept hidden from mens observation.This is the reason, perhaps, that Locke adds the phrase that it was persons withpenetrating minds who began by rejecting Molyneuxs response, but then changedtheir minds when listening to the reasons Molyneux gave.

Ironically then, the Molyneux problem was used to eliminate a prejudice con-cerning perception, yet ended up creating one of its own, i.e., regarding how itshould be interpreted. Starting with Berkeley, everyone takes for granted thatLockes discussion of the question concerns the relation between sight and touch,and everyone tends to emphasize the limits of sight in the perception of three-dimensional shapes. This approach does not, in my opinion, correspond to theproblem that Lockes discussion of Molyneuxs question was intended to illustrate.

57 Essay, II, ix, 12.58 Essay, II, ix, 9.59 Essay, II, ix, 10.

color, space and figure in locke - berchielli

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