Shopping for Apples and Appendixes

This is the final installment of my ongoing series of posts on Reid's shop argument.

In my previous post, I noted that the sceptic’s attempt to refute step (1) of the Shop Argument fails. However, the sceptic can also attempt to undermine the Shop Argument by refuting step (2); that is, the sceptic may argue that the fact that two faculties come from the same shop does not imply that they are equally trustworthy. In fact, it is quite easy to construct a counterexample to step (2) of the Shop Argument. For instance, the Apple computer company manufactures both ipods and desktop computers.

Now I am a big fan of the Apple ipod and would gladly class it among the ten greatest 21st century inventions. However, I also believe that the Apple desktop operating system remains the most non-user friendly invention to curse the planet and that their production should be immediately discontinued. (Okay, so I don't really believe this, but let us just suppose that this is true for the sake of argument.) The fact that both Apple ipods and desktops are produced by the same manufacturer, and even constructed in the same factory in Thailand, does little to ameliorate my approval of the former and disapproval of the latter. In short, the fact that both come from the same shop hardly seems like sufficient reason to assume they are of equal quality.

The same point can be made using an example from the natural world. For instance, few naturalists would disagree with the claim that the human eye is a marvel of biological engineering and that it executes its function in a superbly exquisite fashion. However, the same could hardly be said for the vermiform appendix, which fails to perform the task it was originally designed for and may even become inflamed and rupture, resulting in the painful death of its human host. Admittedly, both the eye and the appendix were produced in the same factory of nature, but while one works wonderfully the other doesn’t seem to work at all.

(NB: There has been speculation among scientists that the appendix may play some yet unknown lymphatic, exocrine, endocrine function. However, most physicians and biologists agree that it is merely a vestigial organ (a leftover from our cellulose-digesting herbivorous ancestors) that presently serves no significant function in humans.)

Consequently, the fact that two things proceed from the same shop or manufacturer does not entail that they are equally effective. A further story must be provided if we are to assume that the efficacy of the one entails the efficacy of the other. The need for Reid to provide additional grounds in support of the Shop Argument is made even more acute in light of the sui generis nature of reason vis-à-vis the senses. What makes the Apple and appendix analogies particularly striking is that the respective manufacturers (namely, the Apple computer company and Nature) produce very different products. If Apple only produced desktops and laptops, then one wouldn’t expect much of a difference in the quality of their products since both are merely types of computers. However, ipods are sufficiently different from computers to allow for a significant disparity in quality between the two.

Likewise, the fact that our rational faculties are sui generis vis-à-vis our sensory faculty increases the likelihood that there may be a difference in the reliability between the two. In brief, the sui generis nature or reason vis-à-vis the senses places a greater burden on Reid to say why he assumes that the reliability of one entails that of the other. This is not to deny that both our rational and sensory faculties are products of Nature—i.e., come from the same shop. Rather, it is to recognise that the same shop may produce two very different products of radically different quality.

Shopping for an Efficient Cause (Part 2)

In my previous post, Shopping for an Efficient Cause (Part 1), I presented an argument against Reid's "same shop" argument. In this post, I will say why I think the previous argument fails and point towards a more effective strategy for combating the Shop Argument.

As we noted earlier, Reid accepts the first three premises aforementioned argument. Moreover, premise 4 follows from premises 2 and 3. However, premise 5 does not follow from premises 1 and 4. Premise 5 confuses the claim of premise 4, that sensory receptions and rational judgements have different efficient causes (a thesis Reid would accept), with the thesis that the sensory faculty and the rational faculty have different efficient causes (a thesis Reid would reject).

Although we are the efficient cause of our rational judgements, we are not (by Reid’s lights) the efficient cause of our rational faculty. What is at issue in the Shop Argument is not the acts of judging or sensing but rather the faculties involved. Reid’s point is that the faculties (not the actions they perform) both come from the same shop. Thus, although we are the efficient cause of our rational judgements, God is the efficient cause of our rational faculty. Since God is also the efficient cause of our sensory faculty, then both the rational and sensory faculties do come from the same shop after all. Consequently, the sceptic’s attempted refutation of the first step of the Shop Argument fails.

Though unsuccessful, the sceptical argument just limned is instructive since we are now closer to explaining what makes reason sui generis vis-à-vis the senses. Reason is not sui generis because the rational faculty comes from a different shop to the sensory faculty. What sets reason apart from the senses is that we are the efficient cause of our rational judgements but not of our sensory deliverances. Herein also lies the explanation for the unilateral relationship between reason and the senses I promised to provide earlier. Since I am the efficient cause of my rational deliberation, I am unconstrained in my attempts to weigh evidence and arguments. The same, however, is not true of my sensory deliverances—i.e., I am not free to decide whether or not I see a red flower before me. I am of course free to doubt the reliability of what I see. For instance, for whatever reason (i.e., I just ate a handful of ‘magic’ mushrooms) I may decide to doubt that the red flower I see before me is really there. However, my doubting the reliability of what I see does not change the fact that I am seeing it. Thus, when it comes to the content of my sensory deliverances I am (at least in this respect) completely passive.

The upshot of the above observations is as follows: We noted that it is because I am the efficient cause of my rational judgements that I am free to weigh and evaluate evidence. Without such freedom, my beliefs would amount to mere effects at the end of a long causal chain leading back to the first cause (i.e., God), and my personal rational agency would be lost. However, that which qualifies reason to engage in its evaluative capacity is the very thing that the sensory faculty lacks.

This observation also explains my earlier claim that the senses can never be used to evaluate our rational judgements. In sum, the fact that I am the efficient cause of my rational judgements allows reason, given the right circumstances, to effectively evaluate the reliability of the senses. Since we are not the efficient cause of our sensory deliverances, the sensory faculty lacks the unfettered (which is to say ‘autonomous’) evaluative capacity necessary to assess the reliability of our rational deliberations. This difference between reason and the senses gives rise to the unilateral relationship between the two that serves as the basis for the sui generis thesis. In my next post on this topic I will outline the implications of the sui generis thesis for Reid’s Shop Argument.

Shopping for an Efficient Cause (Part 1)

I am continuing my series of posts on Thomas Reid. Let us recap Reid’s Shop Argument:

Reason, says the sceptic, is the only judge of truth, and you ought to throw off every opinion and every belief that is not grounded on reason. Why, sir, should I believe the faculty of reason more than that of perception?—they came both out of the same shop, and were made by the same artist; and if he puts one piece of false ware into my hands, what should hinder him from putting another?

This argument can be broken down into three steps:

1. Reason and the senses both come from the same shop. (premise)
2. That two things come from the same shop implies they are equally reliable. (premise)
3. Reason and the sense are equally reliable. (From 1 and 2)

Given that reason and the senses are equally reliable, the sceptic who privileges reason above the senses is guilty of an unwarranted epistemological prejudice.

One way in which the sceptic can resist the Shop Argument would be to reject the first step; namely, that reason and the senses come from the same shop. But how are we to understand the ‘same shop’ metaphor? Reid never explicitly spells out what he means when he says two things come from the same shop, though he does explicitly equate it with two things being “made by the same artist”. Thus, at least one way to understand the same shop metaphor is in terms of efficient causes. That is, two things are from the same shop if they share the same efficient cause (for example, God). By implication, things with different efficient causes can be described as coming from different shops, having been made by different artists.

Given the above reading of what it means for two things to come from the same shop, the sceptic prima facie seems able to construct a refutation of the first step of the Shop Argument. In Essays on the Active Powers, Reid asserts that human beings are the efficient cause of their actions. In this claim he stands in contradistinction from Malebranche (who held that only God is an efficient cause) and Hume (who denied efficient causes altogether). Reid insists that humans are the efficient cause of their actions in order to preserve, among other things, the idea of moral responsibility. While Reid does not explore the epistemic implication of this thesis I believe it is safe to assume on Reid’s behalf that we are the efficient causes of our rational judgements as well. That is, just as being responsible moral agents requires that we be free to choose among moral alternatives, being responsible epistemic agents implies that we are free to weigh and discriminate between rational arguments. In sum, we cannot be held responsible as rational agents if God (or some other external entity) is the efficient cause of our rational deliberations. I will refer to the idea that we are the efficient cause of our rational judgements as epistemic-agent causation (or EAC).

If being responsible epistemic agents entails that we are the efficient cause of our rational judgements, then the notion that the external world exerts some sort of influence on our empirical beliefs requires that we are not the efficient cause of our sensory receptions. This is not to deny the Reidian notion that our rational powers are active when we judge that we see a chair. Rather, it is to recognise that if Reid is to maintain that our beliefs have empirical content at all, he must distinguish between an active faculty of rational judgment and a passive faculty of sensory receptions. In brief, I cannot be the efficient cause of the fact that I see a red flower in front of me if I am to preserve the idea that there is an external world that gives rise to my perceptions. I will refer to the notion that we are not the efficient cause of our sensory receptions as the passive receptivity thesis (or PRT).

If we concede both EAC and PRT, then we are free to construct the following reply to the first step of the Shop Argument:

1. That two effects have different efficient causes implies they come from a different shop. (premise)
2. Human beings are the efficient cause of their rational judgements. (EAC)
3. Human beings are not the efficient cause of our sensory receptions. (PRT)
4. Sensory receptions and rational judgements have different efficient causes (From 2 and 3)
5. The sensory and rational faculties do not come from the same shop (From 1 and 4)

If the sensory and rational faculties do not come from the same shop, as the above anti-Shop Argument argues, then Reid has been denied a premise he needs for his Shop Argument to work. In my next post on this topic I will look a possible objection to 1-5.

Shopping for the Sui Generis

In this post I will be further developing the reply to Reid adumbrated in my previous post; what I will refer to as the sui generis thesis. This thesis is not in tension with Reid’s observation that all the cognitive faculties are equally susceptible to “disorders of the body”. To wit, I am not claiming that reason is somehow less fallible than the faculty of sense. For example, we can imagine someone in the exact opposite position to Nash; someone whose schizophrenia utterly undermined the reliability of their rational faculty while leaving their sensory faculty perfectly intact. I do not wish to deny such a possibility.

My point is that if someone’s reason were so corrupted, there would be no way for them to use their sensory faculty to discover this fact. By contrast, in the case of someone whose sensory faculty is compromised by schizophrenia, it is nevertheless conceivable that they could discover this fact using their rational faculty (in fact, this is precisely what John Nash does).

Reid may object to my Nash counterexample by pointing out that John Nash could only use his reason to evaluate his sensory deliverances because he had prior veridical sensory experiences to use as a paradigm. But if we were to posit, let us say, a global scepticism in which the senses were always mistaken, reason would be powerless to discover this fact. The upshot of this objection is that reason could not effectively evaluate the senses independent of prior aid from the senses themselves.

However, the preceding objection merely points out that there are certain circumstances (i.e., in the case of pervasive sensory scepticism) in which reason would be unable to effectively evaluate the reliability of the senses. However, the sui generis thesis does not rely on the bold (and implausible) claim that reason is always able to effectively evaluate the reliability of the senses. Rather, it rests on the much more modest (and highly plausible) claim that it is possible, given the right circumstances, for reason to evaluate the senses. To wit, if we grant that it is never possible to use the senses to evaluate the reliability of reason, then it merely has to be the case that under some circumstances we may effectively use reason to evaluate the reliability of the senses in order to establish a unilateral relationship between the two faculties.

In sum, I am not claiming that reason is somehow free of the foibles that threaten the senses. Neither am I suggesting that reason can always be effectively used to evaluate the reliability of the senses (i.e., independent of prior aid from the senses themselves). Rather, I avow that there is a unilateral relationship between reason and the senses in that (under favourable circumstances) the former can be used to discover defects in the latter but not vice versa. I believe this unilateral relationship between reason and the senses is sufficient to establish, contra Reid, that there is something sui generis about reason vis-à-vis the senses.

In my next post on this topic, I will provide an account of what makes reason sui generis vis-à-vis the senses and outline how the sui generis thesis bears on Reid’s Shop Argument.

Reid's "Same Shop" Argument (Part 2)

The central contention of the Shop Argument is that our trust in our sensory faculty (along with the other cognitive faculties) is a first principle just like our trust in reason. The reliability of both faculties is derived from the same place—i.e., how we have been designed by Nature—and neither is therefore better than the other. In a slogan, all first principles are created equal.

However, pace what Reid has to say on the matter it seems to me that there is in fact something special about the rational faculty that sets it in sharp contradistinction to the sensory faculty. Specifically, there appears to be a unilateral relationship between the two faculties such that our rational deliberations can be employed to evaluate the reliability of our sensory deliverances, but our sensory deliverances cannot be used to evaluate our rational deliberations.

This claim is illustrated by the Ron Howard film, A Beautiful Mind, which is loosely based on the life of the mathematician and winner of the 1994 Noble Prize in Economics, John Forbes Nash. In the movie, Nash suffers from an extreme form of paranoid schizophrenia that gives rise to sensory experiences (both visual and auditory) of people, places and objects that do not exist. Nash’s hallucinations are phenomenally indistinguishable from actual objects. However, he learns to use his superior gifts of logical reasoning to figure out which phenomena are real and which are not. (For example, he is able to deduce that his supposed best friend Charlie was merely a hallucination by noticing small inconsistencies in his dress and in the way he aged.)

We have no problem imagining someone using their rational faculty to evaluate the veridicality of their sensory deliverances in the manner John Nash did. However, it only takes a moment’s reflection to realize that it would be absurd to talk about someone using their sensory faculties to determine whether or not their rational judgements are veridical. Thus, while we can imagine using reason to evaluate the reliability of the senses, we cannot imagine using our senses to evaluate the reliability of reason. I believe that this unilateral relationship between reason and the senses suggests that there is something unique about the rational faculty that sets it apart from the faculty of sense. I will refer to this thesis by saying that reason is sui generis vis-à-vis the senses. In my next post on this topic, I will develop my sui generis thesis further and respond to one possible objection to my proposal.

Reid's "Same Shop" Argument (Part 1)

External-world scepticism is the thesis that we cannot know that the external world exists or that it is as we perceive it to be. The canonical summary of Reid’s reply to external-world scepticism is that found in chapter 6 of the Inquiry:

The sceptic asks me, Why do you believe in the existence of the external object which you perceive? This belief, sir, is none of my manufacture; it came from the mint of Nature; it bears her image and superscription; and, if it is not right, the fault is not mine: I even took it upon trust, and without suspicion. Reason, says the sceptic, is the only judge of truth, and you ought to throw off every opinion and every belief that is not grounded on reason. Why, sir, should I believe the faculty of reason more than that of perception?—they came both out of the same shop, and were made by the same artist; and if he puts one piece of false ware into my hands, what should hinder him from putting another?[Inquiry, VI, 20: 168-9]

Reid notes that whether we believe that the objects we perceive exist independently of our perceptions is not up to us. To wit, when it comes to the external world, to believe or not to believe is never the question. This belief is something that arises from how we have been constituted by Nature and is therefore something over which we have little or no control. At first glance, Reid seems to be suggesting that we can’t be held responsible for the fact that we believe in the external world since we simply have no choice in the matter. This interpretation is further supported by Reid’s mot: “if it [belief in external objects] is not right, the fault is not mine”. However, to say we can’t help but believe in an external world would be to offer exculpations when what the sceptic demands are justifications. That is, the fact that we cannot help but believe in the external world does not imply that we should believe in the external world.

However, I believe Reid’s argument is much more subtle and sophisticated than it may first appear. Reid is not simply saying that we cannot offer a rational justification for our belief in the external world. He is making the further point that such a belief is not the kind of thing one should offer a rational justification for. In brief, our belief that our senses provide us with reliable knowledge of the external world is a first principle—that is, a belief that arises out of how we have been constituted by Nature:

All reasoning must be from first principles; and for first principles no other reason can be given but this, that, by the constitution of our nature, we are under a necessity of assenting to them. Such principles are parts of our constitution, no less that the power of thinking: reason can neither make nor destroy them; nor can it do any thing without them. [Inquiry, VI, 7: 71]

Among the first principles is included the belief that our faculty of sense is a reliable source of knowledge. Our trust in this faculty is independent of reason, which is itself merely one among the several cognitive faculties we take to be reliable because of how we have been designed by Nature.

Reid can therefore be described as offering a poly-foundationalism. Cartesian foundationalism (or what may just as easily be called traditional foundationalism) is the idea that there is some indubitable first principle upon which all our other beliefs can be built—it is where the epistemic buck stops. However, Reid represents a poly-foundationalism in that he offers not one, but several first principles. But the most distinctive feature of Reid’s foundationalism is that he sees reason as merely one among the many sources of knowledge. Within the Cartesian rationalist system, only beliefs that bore reason’s stamp of approval were deemed acceptable. However, the Reidian system forsakes the monopoly of reason found in Cartesianism and in its place establishes an epistemological oligarchy comprised of various first principles, each equally authoritative in their own right.

The mistake the sceptic makes, then, is seeking for rational justifications in places where she has no business looking. Our belief that our sensory faculty is, all things being equal, trustworthy is a first principle that stands on its own two feet and does not need to be vindicated by reason. This is not to deny that we may sometimes be mistaken about our perceptual beliefs. However, the fallibility of the sensory faculties is shared by all other faculties, including reason:

They are all limited and imperfect…We are liable to error and wrong judgment in the use of them all; but as little in the informations of sense as in the deductions of reasoning. And the errors we fall into with regard to objects of sense are not corrected by reason, but by more accurate attention to the informations we may receive by our senses themselves.[Essays, II. 22: 252]

Reid maintains that if we reject the faculty of sense we must reject the faculty of reason as well since they both share the same foibles. In sum, since no cognitive faculty is in anyway privileged above the others, they all stand or fall together:

Thus the faculties of consciousness, of memory, of external sense, and of reason, are all equally gifts of Nature. No good reason can be assigned for receiving the testimony of one of them, which is not of equal force with regard to the others.[Essays, VI. 4: 463]

Relevant Reading:
De Rose, Keith. (1989). ‘Reid's Anti-Sensationalism and His Realism’, Philosophical Review. 98, 313-348.

Greco, J. (2004). ‘Reid’s Reply to the Skeptic’, The Cambridge Companion to Thomas Reid. T. Cuneo and R. Van Wouldenberg (ed.), Cambridge: Cambridge University Press.

Reid, T. (1969). Essays on the Active Powers of the Human Mind, (ed.) Baruch A. Brody (ed.), Cambridge, MA: MIT Press.

Reid, T. (1990). Practical Ethics, (ed.) Knud Haakonssen, Princeton: Princeton University Press.

Reid, T. (1997). An Inquiry into the Human Mind on the Principles of Common Sense, (ed.) Derek R. Brookes, University Park: Pennsylvania State University Press. (Inquiry)

Reid, T. (2002). Essays on the Intellectual Powers of Man, (ed.) Derek Brookes, University Park: Pennsylvania State University Press. (Essays) Yaffe, G. (2004). Manifest Activity: Thomas Reid’s Theory of Action. Oxford: Clarendon Press.