Reid's response to Hume's perceptual relativity argument

Abstract

Reid declared Hume's appeal to variation in the magnitude of a table with distance to be the best argument that had ever been offered for the ‘ideal hypothesis’ that we experience nothing but our own mental states. Reid's principal objection to this argument fails to apply to minimally visible points. He did establish that we have reason to take our perceptions to be caused by external objects. But his case that we directly perceive external objects is undermined by what Hume had to say about the role played by color in our perception of the primary qualities of bodies.

Keywords::

• Reid
• Hume
• direct realism
• representationalism
• perspectivalism

Notes

^1. Reid (1785) 2.14: 179/12–15. References to this work are to essay and chapter numbers, supplemented by references to the pagination and line numbers of Reid (2002). These works will hereafter be referred to as Intellectual Powers.

^2.Intellectual Powers 2.14: 178–183. One commentator who does not endorse Reid's objection is John Wright (1983, 81 n.20).

^3. James Somerville (2006) is more concerned to take Reid to task for not following his own line of criticism of Hume's argument than to identify any particular mistake in Reid's actual objection. Van Cleve does go so far as to mention, in a footnote (2004, n.4), that aspects of Reid's argument depend on a ‘dyadic’ analysis of the notion of appearance, but does not consider whether Reid was entitled to that analysis – a supposition that will be questioned in what follows.

^4.Intellectual Powers: 178–179, citing Hume. The actual text of Hume, 1750, 239–240, is given in square brackets, where it deviates from Reid's citation, omitting variations in spelling, capitalization and the use of equivalents, e.g., ‘betwixt’ for ‘between’. I compare Reid's citation to this edition (which is readily available in the ECCO database) rather than Beauchamp's modern critical edition because it is the one that was consulted by important contemporary critics such as Campbell and Price. In the absence of further indication I consider it likely to have been the one consulted by Reid as well. Principal differences from Hume 1777, the last edition to have been edited by Hume, are also noted. Text in the initial set of brackets is explanatory by reference to earlier passages. Hume (1750/1777) will hereafter be referred to as EHU and cited by section and paragraph numbers, following the numbering scheme in Hume (2000).

^5. Compare Hume (1739, 367–368) on the crucial role of lack of independence in establishing sceptical doubts about the evidence of the senses. This work will hereafter be referred to as Treatise or T and cited by book, part, section, and paragraph numbers, following the numbering scheme established in Hume (2007). The passage just cited is from 1.4.2.44–45.

^6. For a rather more fraught and less sympathetic take on Hume's argument see Somerville (2006). For textual justification for reading Hume's references to diminution as references to loss of parts, see section 4 below.

^7. Not all would agree. For an opposed opinion, see Butler (2008).

^8. Take M to be the property ‘varies in magnitude with changes in distance,’ s to be the table we see, and r to be the real table.

^9. The argument would continue: We nonetheless see something: ∃ xs = x. Call what we see an image of the table: s = i. / The thing we see is not the real table but an image of the table: ∃ xx = s & ∼s = r & s = i.

^10. Take P to be the second order property, ‘apparent,’ and R the second order property, ‘real.’ Of course Reid did not use the apparatus of second order predicate logic to diagnose the problem with Hume's argument. Using the terminology of the logic of the day, he declared it to be a syllogism that fails because it has two middle terms (Intellectual Powers II.14: 182/25–26). Either way, the problem being brought up is the same: the argument equivocates.

^11. ‘The argument is this, the table we see seems to diminish as we remove farther from it; that is, its apparent magnitude is diminished; but the real table suffers no alteration, to wit, in its real magnitude; therefore it is not the real table we see’ Intellectual Powers II.14: 182/21–24.

^12.Intellectual Powers: 180–181.

^13.Intellectual Powers: 181/7–8. Since the object really does subtend a specific angle for each particular vantage point, ‘apparent’ is something of a misnomer for what is actually another among the real qualities of an object. See further Intellectual Powers II.19: 225/9–12.

^14. I take it that apprehending magnitude or the distance between points on the periphery of an object is not something that can be readily distinguished from measuring this distance or magnitude, particularly in contexts where what is at issue are claims about a diminution in the magnitude of the table we see. Measurements may be made by more precise or more approximate means, but apart from some means of estimating the magnitude of an object it is hard to understand what it would mean to ascribe any magnitude to it, and particularly hard to understand what it would mean to say that the magnitude diminishes.

^15. Hume 1740, 305–6. The appendix contained in this work will hereafter be referred to as Ax and cited by the paragraph numbers established in Hume 2007, 396–401. The passage just cited is Ax 22.

^16. This work will hereafter be referred to as NTV and cited by the paragraph numbers published with the original edition. The passage just cited is from NTV 12.

^17. For a raft of citations from other authors see George (2006, 147–148).

^18. Take N to be the property ‘varies in number of parts with changes in distance’

^19.Intellectual Powers II.19: 224/30–31, cf. Reid, 1764, 219, 241. This work will hereafter be referred to as Inquiry and referenced by chapter and section number supplemented by the page and line numbers of Reid, 1997. The passage just referenced is Inquiry 6.7: 96/16–18 and 6.9: 104–105. Reid's antecedent tenet that visual space has the topology of the inner surface of a sphere, might be questioned by some, but the crucial claim is that any portion of visible space stands in a finite ratio to the whole of visible space, and this would have to be accepted by anyone who accepts that the momentary field of view is bounded and that immediate perceptions of magnitude are based on what is present on the momentary field of view. Though Hume did no declare himself on this matter anywhere that I am aware of, I assume that he would have agreed that both the visual and the imaginary fields are bounded. To suppose otherwise would be inconsistent with his declarations about the finite capacities of the mind at Treatise 1.2.2.

^20. The connection is made by considering the center of the eye to be located at the center of a sphere and the objects of vision to be projections on the inner surface of this sphere made by lines passing from the center point through each point of the real object (Inquiry 6.7: 95/29–32). This construction is in turn justified by the claim that it is precisely by means of such a projection that retinal images are formed (Inquiry 6.7: 95/33–34), and the further claim that retinal images determine the immediate objects of vision (Inquiry 6.22: 120/18–25).

^21. Though he spoke here of ‘an object of touch only’ it was important to Reid to establish that we do see real magnitude (Intellectual Powers II.14: 181–182). For Reid, we just don't see it immediately. However, in what follows it will be immediate visual (and tangible) perception that is at issue.

^22. Reid considered tangible magnitude to be measured by lines and visible magnitude by angles (Intellectual Powers II.19: 224/27–30). But Berkeley measured the apparent visible magnitude of the moon by a line of minimally visible points (NTV 44) and maintained that both visible and tangible magnitude are a function of number of minimally sensible points (NTV 54, 112).

^23. Reid identified real magnitude with juxtaposition with standard units, and if we can immediately see anything we can immediately see one thing standing alongside another thing and see that the one is as high or higher or shorter than the other, especially when all the objects lie in the focal plane (as is typically the case with measuring instruments visually aligned with their objects) so that depth perception is not an issue.

^24. Take NV to be ‘varies in number visible parts’ and NR ‘varies in number of real parts’.

^25. This is a consequence of the second premise of the earlier argument. Given that the real table continues to equal the same number of juxtaposed standard units with changes in distance, we can infer that there has been no change in the number or distribution of its actually constituent parts.

^26. For reasons to think Reid could not defend direct perceptual realism, independently of anything Hume said, see Van Cleve (2002). The account of Reid's views that I give here advances an interpretation originally proposed by Susan Weldon (1982), and further developed by Giovanni Grandi (2006).

^27. Take an icon to be an object that bears no salient resemblance to another object but that is stipulated or conventionally recognized to serve as a sign for that object.

^28. Like Hume, I believe that all of us become people of common sense when we leave the study and so are all qualified to say what common sense maintains. My common sense as a sighted person tells me nothing as clearly as that colors are not invisible qualities but manifest ones. It also tells me that these same manifest qualities are spread out in space. An indication that others share my common sense can be gleaned from how they use color terminology. They speak of the manifest qualities that Reid declared to be sensations of color 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 their color sensations, and all they ever say in consequence is that the invisible 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. For more on this point, and a fascinating discussion of how it was anticipated by one of Reid's early critics, see Grandi's essay in this volume.

^29. Thanks to Patrick Rysiew and Todd Buras for astute and formative comments on an earlier draft of this paper, and to the other contributors to this volume for helpful reactions to a version presented at a joint symposium at the University of Vermont, November, 2013.

Additional information

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Lorne Falkenstein

Lorne Falkenstein holds the rank of Professor in the Philosophy Department at Western University, London, Ontario, where he has been employed since 1987. He has written articles and books on a number of 18th century philosophers and has co-edited, with Neil McArthur Hume's Essays and Treatises on Philosophical Subjects for Broadview Press.