The extension of color sensations: Reid, Stewart, and Fearn

Abstract

According to Reid, color sensations are not extended nor are they arranged in figured patterns. Reid further claimed that ‘there is no sensation appropriated to visible figure.’ Reid justified these controversial claims by appeal to Cheselden's report of the experiences of a young man affected by severe cataracts, and by appeal to cases of perception of visible figure without color. While holding fast to the principle that sensations are not extended, Dugald Stewart (1753–1828) tried to show that ‘a variety of colour sensations is a necessary means for the perception of visible figure.’ According to John Fearn (1768–1837), two motives appear to be central to Reid's views about color sensations and extension: his commitment to the Cartesian doctrine of the immateriality of the soul, and his attempt to evade ‘Hume's dilemma’ about the existence and immateriality of the soul.

Keywords::

• vision
• color
• sensation
• extension
• mind-body dualism
• Thomas Reid
• Dugald Stewart
• John Fearn

Acknowledgements

I would like to thank Lorne Falkenstein and Patrick Rysiew for comments on this paper. I would also like to thank the participants to the meeting ‘New Essays on Reid,’ held at the University of Vermont, 1–2 November 2013.

Notes

^1. Reid also refers to color sensations as ‘the appearances of colors.’ Thus, to speak of ‘manifest color qualities’ is only a slight departure from Reid's own terminology.

^2. Writing in this volume Lorne Falkenstein has observed that ordinary people speak of manifest color qualities ‘as if they were external and located on the surface of bodies. Reid would have liked to deny this and maintain that our sensations of color are so insignificant to us that they have not been thought worthy of being given names in any language, so that all anyone ever means to do when speaking of color is to refer to the invisible causes of our color sensations, and all they ever say in consequence is that the causes of their color sensations are external and located on the surfaces of bodies. The implausibility of this position is proven by the significant sums of money people of ordinary common sense are willing to spend on cosmetics, clothes, paint, interior decoration, gardens, etc. The members of a society of blind people would have no interest in spending money on such things, which are valued only for the sake of the visual sensations they produce in us. The members of a society that considers sensations of color to be so insignificant as not even to be worthy of being named should have attitudes that are no different from those of the blind.’

^3. On the question whether there is a sensation proper to visible figure, see Reid (1997), VI.8: 99/5–101/23 and VI.21: 176/30–37. This part of Reid's Inquiry has been object of debate: Yaffe (2003a); Falkenstein and Grandi (2003); Yaffe (2003b); Nichols (2007). Reid also claimed that the vulgar always ascribe the name ‘color’ to the unknown quality in the external object rather than to the appearance of which they are conscious: see Reid (1997), VI.4: 87/9–25.

^4. Fearn's interpretation is similar to that presented independently in recent times by Lorne Falkenstein: see Falkenstein (2000) and (2005).

^5. See Yaffe (2003a).

^6. See Hume (2000), 1.4.5.7–16 and 33.

^7. The alternative that the soul might be extended is not an option Hume recognized, though Reid claimed he did.

^8. See Reid (1997), VII: 217/5–26. Reid does not discuss these arguments in the Inquiry. On the question of the immateriality of the soul, see also the Three Lectures on the Nature and Duration of the Soul, published in Reid (2002a), 617–631, and Paul Wood, Introduction, in Reid (1995).

^9. See Reid (2002a), II.2: 76/17–25.

^10. See Hatfield (1990), Ch. 4, especially 131–143.

^11. Reid explains the reasons for his modification of Porterfield's original statement in Reid (1997), VI.12: 123/17–27.

^12. Another case of innate mechanism of localization of a secondary quality is probably that of heat and cold, although Reid does not clearly say so. The localization of the causes of pain and pleasure also appears to be a case of perception of the location of a hidden cause of sensations in our body on the basis of an innate mechanism. However, in some cases, we do not simply perceive the causes of pain and pleasure to be situated in a particular location in our body. In some instances, we do also have a conception of what causes pain and pleasure (an object touching us with gradually increasing pressure, first giving rise to sensations that are neither painful nor pleasurable and then giving rise to a painful sensation is a case in point). On the localization of the causes of pain and pleasure, see Reid (2002a), II.18: 211–215. See also Falkenstein (2000), 314–317.

^13. See Reid (1997), VI.22: 178–187.

^14. An interpretation of Reid (1997), VI.8, based on this point is proposed by Falkenstein (2000), 318, note 39, and by Falkenstein and Grandi (2003). For an alternative interpretation, see Yaffe (2003a). According to Yaffe, color sensations have a dual function: they suggest both color and visible figure.

^15. See below section 7, where I discuss extensively Fearn's critique. Reid first presented the cataract case in an Aberdeen University Library (AUL) manuscript from 1 December 1758: AUL MS 2131/6/III/8, fols. 1r-v, in Reid (1997), 319/15–320/4. The origin of Reid's interest in the visual abilities of patients affected by severe cataracts is certainly due to his reading of Cheselden's case in the Philosophical Transactions of the Royal Society (1728). William Cheselden, a surgeon at St. Thomas Hospital, London, removed the cataracts from the eyes of a young man. The experiences of the newly sighted young man could finally provide a solution to Molyneux's Question (Reid himself takes the report of the experiences of the young man after the removal of cataracts as confirmation that originally by sight we do not perceive distance). But Reid was also interested in the beginning of Cheselden's report which describes the visual experiences of the young man before surgery: ‘Tho’ we say of the gentleman that he was blind, as we do of all people who have ripe cataracts, yet they are never so blind from that cause, but that they can discern day from night; and for the most part in a strong light, distinguish black, white, and scarlet; but they cannot perceive the shape of any thing; for the light by which these perceptions are made, being let in obliquely thro' the aqueous humour, or the anterior surface of the crystalline (by which the rays cannot be brought into focus upon the retina) they can discern in no other manner, than a sound eye can thro' a glass of broken jelly, where a great variety of surfaces so differently refract the light, that the several distinct pencils of rays cannot be collected by the eye into their proper foci; wherefore the shape of an object in such a case cannot be discern'd, though the colour may,’ quoted by Morgan (1977), 19.

^16. In the manuscripts, Reid also draws an analogy between the constant association of color with visible figure and the constant association of heat and cold with tangible figure: see AUL MS 2131/6/III/8, fol. 3r, in Reid (1997), 324/38–325/11. This analogy may be the background for the analogy drawn between sight and touch in Reid (1997), VI.8: 101/17–23.

^17. See AUL MS 2131/6/III/8, fol. 3r, in Reid (1997), 324/23–37. See also AUL MS 2131/8/II/21, fol. 2v.

^18. In comments to this paper, Lorne Falkenstein mentions cases of uniformly colored visual field caused by ‘white-out’ weather conditions (thick fog or a snow-storm), and by ‘red-out’ weather conditions (a dust-storm). But even in the absence of such conditions affecting the medium between the objects at a distance and the eyes, it is still conceivable to think of objects that reflect the same light to the eyes.

^19. See Fearn (1820), xxi (the epigraph to this paper).

^20. See William Hamilton, Dissertations, Historical, Critical, and Supplementary, Note E, in Reid (1880), vol. 2, 918a.

^21. See Fearn (1820), viii. The analysis of visible lines and figure as relations of contrast between color sensations is carried out by Fearn in Fearn (1820), II.5: 197–212, and Fearn (1829), I: 25–27. He here gives four laws for the perception of visible lines and figures. According to Fearn, lines are external relations holding necessarily among color sensations and known through an act of judgment distinct from mere sensation. He distinguishes this act of judgment whereby borders between contrasting color sensations are seen (similar to ‘ploughing’) from the act of judgment whereby atomic color sensations of the same hue are seen as a continuous expanse (this is similar to ‘harrowing’): see Fearn (1829), IV.2: 153–155. He also comments explicitly on Kant's views, known only second hand (Fearn 1829, IV.3: 161–169).

^22. Stewart (1792), 73–74, and 561–562.

^23. The Dissertation was prefixed to the supplemental volumes of the Encyclopedia Britannica. Stewart's speculations on color occurred in a part where he discusses what he considers to be one of the achievements of Descartes, the distinction between primary and secondary qualities.

^24. For example, if I judge of the distance of a tree by interposition, I must be able to pick out a particular two-dimensional patch of colors, brown and green, distinct from other patches of color in my visual field that signify closer objects.

^25. Stewart's (second) letter to Reid is not included in the critical edition of Reid's correspondence (Reid 2002b), but only in Hamilton's edition of Stewart's works. The first letter of Stewart to Reid is missing, as well as Reid's reply to it to which Stewart refers in the letter published by Hamilton. So we have to rely on Stewart's second letter to Reid to reconstruct Reid's reply to Stewart's criticism. Stewart criticized Reid's use of the term ‘suggestion’ in Chapter 6, Section 8 of the Inquiry. Reid had claimed that the impression on the retina immediately suggests the notion of visible figure. Stewart noticed that this is the only place in the Inquiry where Reid uses the word ‘suggest’ ‘to express the communication of knowledge to the mind by means of something of which we are not conscious’ (Stewart 1854, 133, note 1). Stewart evidently thought that if sensory perception works like a natural language, we must be conscious of the signs at work in it, however little attention do we actually pay to them; in the same manner, we pay little attention to spoken or written words of our artificially constructed languages, and yet it is certain that we are conscious of them, if we have to attend to their meaning. In his second letter to Reid, Stewart proclaimed himself satisfied with Reid's answer on this issue, although it is not exactly clear from Stewart's remarks what Reid's answer was. Probably, Reid said that by the use of the term ‘suggestion’ he just meant a regular succession of events in the process of our perception. Some events in this process are conscious states (our sensations, for example), others are not conscious like the impressions on our sense organs: see Reid (1997), VI.21: 174–178.

^26. Here is what Stewart says in his letter to Reid: ‘I am happy to find, indeed, that our sentiments upon the subject are not so different as I first apprehended, but I do not imagine that they yet entirely coincide. You seem to acknowledge that the mode in which we obtain the perception of visible figure is precisely similar to the mode in which we obtain the perception of tangible figure. So far I perfectly agree with you. And I apprehend you will likewise acknowledge the reasonings which you have advanced upon the perception of visible figure are applicable to our perception of extension both by sight and touch. This observation had occurred to me before the first time I wrote to you. But as you have taken no notice of it in your Inquiry, and as, in another part of your book, ([Ch. 6, Sec. 8] p. 306 of the 3rd Edition) you have spoken of our perception of visible figure, as an exception from all our perceptions, I was led to conclude that you conceived some peculiarity about it which I did not fully comprehend. It was this which first turned my attention particularly to the subject, and gave rise to the observations which I sent you in my last letter’ (Stewart 1854, 133, note 1). Stewart claims that Reid admitted in his reply that the mode by which we perceive visible figure is precisely similar to the mode by which we perceive tangible figure. This might seem strange, because while Reid thought that there are sensations regularly preceding and thus suggesting our perception of tangible figure, he clearly stated that visible figure is suggested immediately by the impression on the retina. It is true that it is not clear whether he thought there are sensations exclusively suggesting tangible figure, or if he thought there are sensations that suggest multiple items such as hardness and softness, roughness and softness, motion, and tangible figure at the same time. The second reading is justified by the passage in Reid (1997), V.5: 63/3–14. Reid also makes clear that the same sensation by suggesting hardness or softness also suggests extension since this notion is implied in that of hardness and softness: see Reid (1997), V.5: 62/33–63/2. In comments on this article, Lorne Falkenstein suggests that Reid's apparent concession to Stewart should be taken as recognizing that the perception of tangible figure is like that of visible figure: there is no sensation appropriated to tangible figure, and tangible figure is suggested immediately by the material impression. On Reid's account, pressure sensations are confined to suggesting just those primary qualities of a body having to do with the spatial relations among its own parts. They do not tell us where the body is located relative to other bodies causing other pressure sensations.

^27. As we have seen, Reid could grant Stewart that we cannot perceive visible figure without color, that is, that the perception color is a necessary condition of our perceiving visible figure. This is a matter of fact of our experience, not yet disconfirmed by any contrary instance.

^28. See Stewart (1854), 133–135.

^29. Moreover, this isomorphism would not be as strict as the one demanded by the doctrine of local signs, since sensations can somehow change in their mutual order of coexistence without any change in the figure signified: a red triangle against a green background can be identical in visible figure to a green triangle against a red background, but the corresponding color sensations would switch ‘position’ in their non-spatial order of coexistence.

^30. William Hamilton, probably influenced by Fearn, claimed that Stewart's views on color and visible figure in the Dissertation are not compatible with his views in the Elements (Reid 1880, vol. 2, 919). Hamilton reviewed the whole question of color and visible figure in Note E of his edition of Reid's works: see Reid (1880), vol. 2, 917–923. Hamilton, although critical of Fearn's claims to originality, begrudgingly acknowledged his merits: ‘[…] I am far from doubting the personal originality of this perverse, but acute psychologist’ (Reid 1880, vol. 2, 918b). Hamilton also described Fearn as ‘a rare metaphysical talent though unendowed with even an ordinary faculty of expression’ (Reid 1880, vol. 2, 923b). John Fearn was a retired officer of the Royal Navy and the merchant navy. As a captain of a whaling ship he discovered an island in the South Pacific, now the independent country of Nauru. In a sketch of autobiography in one of his late works, he writes that after his retirement from the ‘maritime life,’ he spent some years ‘occupying a position in the Interior Regions of one of those Lands,’ presumably somewhere in South-Asia or Southeast-Asia. In this ‘lone and long seclusion,’ he spent a considerable amount of time reading Locke's Essay concerning Human Understanding (‘a fortunate accident, which gave to my mind its first cast towards Philosophy’). The only other diversion was that of hunting, or as he says ‘riding, frequently, upon an elephant, or on horseback; and invading the repose, and disturbing the life, of the Wild Boar, and the Buffalo in their lairs: Together with a varied, and most unsparing, slaughter of the lesser animals which Providence had subjected to my truly savage propensity’ (Fearn 1837, 7–9). After his return to London, he published a plethora of works during the course of almost thirty years of activity. Fearn's various contributions on the problem of color and visible figure are listed in the bibliography: in Fearn (1810/1812), (1813a) and (1813b), he still subscribes to a form of realism about matter. For his mature and complete views on the question, see in particular Fearn (1820) and (1829). Fearn's philosophy is briefly discussed by Atherton (2005).

^31. See Stewart's letter, in Fearn (1820), xiii–xiv. Fearn did not accuse Stewart of plagiarism, and he only insisted on his priority in the discovery that a variety of sensations is necessary for the perception of visible figure. Most importantly, he insisted on his priority in the discovery of the principle of explanation lying behind this fact, that is, that visible figure is a relation of contrast between two color sensations. Hamilton, as editor of Stewart's works, defended Stewart in the priority controversy with Fearn. According to Hamilton, Stewart's letter to Reid, ‘“of forty years before” […] completely vindicates’ Stewart's statements (Stewart 1854, ix, note). Thus, Stewart was already stating that the ‘varieties in our perceptions of colour are the means of our perception of visible figure’ in his letter to Reid from 1775 (Stewart 1854, 134, note 1).

^32. Fearn had submitted to Stewart his first work, An Essay on Consciousness (1^st edition 1810, 2^nd edition 1812) sometime before the publication of Stewart's Dissertation in 1815, thus justifying in his mind an unspoken suspicion that the view that color sensations are extended had been gleaned from that early work. In that work, Fearn had explicitly conceived the mind to have the shape of a ‘spherule,’ a small sphere located somewhere inside the brain. The work was later repudiated by Fearn not only because of the hypothesis of the spherule (revived later in his life by Fearn), but also because of its realism about matter. Stewart had quickly dismissed the work upon reading of the hypothesis of the spherule. This hypothesis may have irremediably tainted the reputation of Fearn in Stewart's mind.

^33. See Fearn (1820), I.1: 21.

^34. Fearn (1820), I.1: 24–25. Fearn compared his metaphysics to ancient ‘Hindoo’ philosophy. The external bodies we know through sensations are only activations of latent ‘energies’ of an infinite spirit – a spirit infinitely extended in three-dimensions and ultimately identical to space itself. Despite the radical aspects of his views about the nature of the external world, Fearn was aware that his ideas on the mind were not original. Fearn explicitly mentioned Newton's view of space as the sensorium of God and Newton's allusions to a seat of the soul somewhere in the brain as representatives of the more sensible view that, without giving up thought as an essential attribute of mind, makes the mind spatially extended. Oblivious to the possibility of a materialist interpretation of Locke, Fearn also enlisted the author of the Essay concerning Human Understanding in this tradition. However, he did not mention Henry More, who, in his polemic with Descartes, best represented the ‘third party’ on the nature of the soul. Ralph Cudworth and Samuel Clarke also held views similar to those of Fearn. The view itself had a long history: see Bréhier (1937). Fearn's main source for his knowledge of ancient Indian philosophy is William Jones, an author mentioned by Stewart in his PhilosophicalEssays (1810): see Stewart (1855), 107–108. Schopenhauer also relied on William Jones’ works for his knowledge of Indian philosophy, but he drew from them different conclusions.

^35. Thus Fearn took a definite stance on the vexed question of what was the ‘ideal theory’ that Either Reid rejected in his writings. Either Reid's arguments are only against ideas considered as special entities standing between the mind and external qualities, or his arguments also take into account a more nuanced view according to which ideas, which are in themselves modifications of the mind, can make us acquainted with external qualities by being somehow resemblant in their ‘objective reality’ to external qualities. Whatever view we adopt on Reid's critique of the theory of ideas, Fearn was among the originators of the more reductive interpretation, an interpretation towards which the first editor of Reid, William Hamilton, eventually inclined. The other source for the reductive interpretation was Thomas Brown, Lectures on the Philosophy of the Human Mind (1820).

^36. The remarks about Hume's argument in the Inquiry do not allow us to draw a definitive conclusion about the origin of Reid's philosophy. However, we find that Reid worried about the origin of our idea of the self as early as 1749, as one of his early manuscripts show: see AUL MS 2131/6/I/18, in Reid (1997), 316–318.

^37. The original passage in Stewart is slightly different from what Fearn gives as a quotation: ‘[O]ur natural bias is surely to connect colour with extension and figure, and to conceive white, blue, and yellow, as something spread over the surfaces of bodies’ (Stewart 1792, 73–74).

^38. See Falkenstein (2000), 322–323. Falkenstein notices that Reid fails to point out those experiments that make us see that color sensations are not extended. Reid describes an experiment revealing the existence of double appearances in our visual field in Reid (1997): VI.13: 133/36–134/10.

^39. The hypothesis that what we immediately see is similar to the image on the retina has been called the ‘constancy hypothesis’: see Pastore (1971), 11–13.

^40. Hutcheson's passage is quoted by Stewart (1855, Note G, 420) and Fearn (1820, II.9: 248, and 1829, IV.2: 149). The original passage occurs in a wider context in Hutcheson: ‘Some Ideas are found accompanying the most different Sensations, which yet are not to be perceived separately from some sensibleQuality; such are Extension, Figure, Motion, and Rest, which accompany the Ideas of Sight, or Colours, and yet may be perceived without them, as in the Ideas of Touch, at least if we move our Organs along the Parts of the Body touched. Extension, Figure, Motion, or Rest seem therefore to be more properly called Ideasaccompanying the Sensations of Sight and Touch, than the Sensations of either these Senses. The Perceptions that are purely sensible, received each by its proper sense are Tastes, Smells, colours, Sound, Cold, Heat, &c.’ (Hutcheson 2002, 16, note).

^41. Stewart had particularly in mind the experimentum crucis of Reid (1997), V.7: 70/16–27.

^42. See AUL MSS 2131/8/II/21, fol. 2v; 2131/8/VI/3, fol. 1r-v; and the continuous manuscript constituted by MSS 2131/6/III/8 and 2131/6/III/5 (see Reid 1997, especially 327). I consider these manuscripts in Reid (2012), 6–7.

^43. The image of loose and detached ideas ‘flitting, like swallows, into and out of the mind’ can be found in Fearn (1820), I.3: 93 and I.4: 121.

^44. See Falkenstein (2000) and (2005).

^45. See Fearn (1820), I.2: 30–57. The relation between Reid's substance dualism and Newtonian methodological principles is examined by Nichols (2007), 35–38.

Additional information

Notes on contributors

Giovanni B. Grandi

Giovanni B. Grandi is Assistant Professor of Philosophy at the University of British Columbia, Okanagan. Among his published articles are “Thomas Reid's Geometry of Visibles and the Parallel Postulate” (Studies in History and Philosophy of Science, 2005), “Reid's Direct Realism about Vision” (History of Philosophy Quarterly, 2006), “Reid and Condillac on Sensation and Perception: A Thought Experiment on Sensory Deprivation” (Southwest Philosophy Review, 2008), and “Reid and Wells on Single and Double Vision” (Journal of Scottish Thought, 2010). He is the editor of Thomas Reid: Selected Philosophical Writings (2012).