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.

The Nagel Lectures

Columbia University's Philosophy department will be hosting its annual Nagel Lectures on Thursday, September 27th. The first lecture, which will be delivered by Anita Feferman, is entitled "Uncovering Tarski", and begins at 4:00pm in room 716, Philosophy Hall. The second lecture, entitled "Gödel, Nagel, Minds and Machines", begins at 6:15pm in the same venue and will be delivered by Solomon Feferman (winner of the Rolf Schock prize in logic and philosophy). There will be a short reception between the two sessions.

An Argument for Atheism (Martin)

The following is the second installment of a two-part cross-post written by Martin Cooke from Enigmania:

I shall, in this post, take atheism to be the belief that there is (probably) no God, where God will be defined to be an omniscient and omnipotent being that is also totally good (much as Richard defines Him), and I shall argue (as I did briefly in a comment on this post of Richard's) that such a God is (probably) impossible. There are of course other definitions, e.g. atheism is sometimes regarded as the absence of a belief in God, so that it would include both atheism (as defined above) and agnosticism (the absence of a belief either way, which includes the belief that knowledge either way is impossible, which is another definition of agnosticism), and God is sometimes defined to be the Creator of this Universe.

Such a Creator would know (more or less) all that could be known about this Universe, just as an author would know all about her story, or a painter all about his painting; and similarly, such a Creator would have (more or less) complete power over this Universe. So, it may have been that God was originally defined to be the Creator, and that it was then deduced that such a God would be all knowing and all powerful in that sense (which is, after all, the sense that concerns us, as beings within this Universe), and that such properties only then became definitive, e.g. through their apparent utility—certainly many arguments (as in that linked post) do begin by defining God to be infinitely perfect (rather than the Creator). So, I’ll now argue that such a God, which I’ll refer to as ‘He,’ is (probably) impossible.

My argument is primarily concerned with omniscience, with God knowing absolutely everything. Not only does He know everything about His Creation (as any Creator would), He also knows whether or not there are, for example, other Gods. If there are any, He knows everything that they know, including precisely what it is like to be them (which might imply that there is only one God), and if not then He knows how he knows that there are not. But it is quite inconceivable how he could know that there are not any other Gods (either at all, or beyond those that He does know all about). The problem is not so much with the “omni,” but with the “science.” It would of course not follow, from some conjectured infinitude having inconceivable properties, that it did not exist; but the concept of knowledge is the concept of true beliefs that are in some way tied down to (or that in some reliable way arise from) the things known about, and we are here considering one being’s knowledge of the non-existence of other similar beings, where there might well be absolutely no connection between them.

Ironically this problem (for this fairly common kind of theism) resembles a fairly common reply to atheists, who are told that while they might obtain a justified belief that there was a God by His revealing Himself to them, they could hardly obtain scientific knowledge that there was not a God (not even in Heaven) just by failing to have had such a revelation. Imagine (for an analogy) completely separate spacetimes with absolutely no causal connections between them—how could any being, in one of them, know anything about what was going on in the others, or even whether or not there were any others? Similarly, even were there only one spacetime, and a being within it had that true belief, how could that belief be justified?

By hypothesis God would know that He knew everything, and He would also know how he knew that there were no other Gods (beyond any He might know about more directly, via informative connections), but how could that be? Could He have deduced that fact from His knowledge of His own omniscience? But how could He not then know that such circular justification would not make His belief (that there were no other Gods) knowledge? It is all very well for us to define God to be omniscient, because we can then ask whether or not God exists, but God could hardly do that! In short, the concept of omniscience (in this strict, absolute sense) seems to be self-contradictory. It seems to be, but it may not be, but as there seems to be little logical room for manoeuvre, I regard that conclusion as at least very likely (and not necessarily inconvenient for the theist, as I mentioned here).

Regarding omnipotence, if God has the power to do absolutely anything, then could He make 2 plus 2 equal 5? If not then it again seems that we cannot interpret His definition in such a strict way after all. And of course, God would not get any less implausible were combinations considered, such as omniscience and (via free will) responsibility, together with omnipotence and (via this Universe existing, whether or not God created it) evil. After all, if God knows what we are going to do, and if He could have stopped us but did not, then, given that He is good, it seems that whatever we do must also be good, or at least (since we are only human) good enough (in what might have to be the best of all possible worlds), which seems unlikely.

New Philosophy of Mind Blogs

I am pleased to announce that both Tim Crane and Colin McGinn have joined the philosophy blogging world. Go have a peek!

An Argument for Agnosticism (Martin)

The following is a cross-post written by Martin Cooke from Enigmania:

Either the world was deliberately created, so that some sort of theism is true, or else atheism is true, but both options involve us in such mysteries (as the two below) that to choose either, given only such evidence as is publicly available (and so worthy of being called ‘evidence’), would be to favour irrationally one mystery over another, whence agnosticism (i.e. the absence of a belief either way) is to be preferred.

The obvious problem with theism is that, when we look at the world we see only mundane things, no gods and not even angels or fairies. We don’t even see any clear evidence that the world was deliberately created, or is being guided from above, or even watched over. But more importantly our language is so orientated towards the world that we are unable even to form a clear idea of what its creator might be like.

Conversely we know a lot about the world. We even know that our brains are composed of many brain cells, each of which is composed of a lot of organic molecules, many of them highly complicated but all of them composed of atoms. Atoms themselves have a very tidy structure (as shown, for example, by the Periodic table of the elements), and they are the building blocks of, not just brain cells but rodents and radishes, rocks and raindrops, robots and radios.

But it is precisely because we know so much about how atoms behave that it is so troubling that (although we can see how information-processing mechanisms can be composed of them) we are unable to make much sense of the idea of their giving rise to such conscious individuals as we know ourselves to be. We might deduce that there must be more to them than we know at present, but it is quite mysterious even what sort of stuff there would need to be (or even its whereabouts, given how much we already know about atoms).

Perhaps the way that organisms have atoms is akin to how they have skeletons—if the X-ray photograph of an organism shows only its skeleton (which could account for all its scientific properties, had few enough of its properties been observed and measured) that does not mean that there is not more to the organism. But again it is difficult (and not so much because of the complexity as the conceptual obscurity) to make much sense of that idea, not without introducing some sort of non-physical substance (akin to the flesh on the skeleton).

Still, prima facie we are non-physical individuals, and the mysteries of how and why such mental beings interact with physical structures would seem less of a problem (less of an unlikely coincidence) were the world created because then both the mental and the physical would have had a common origin in a deliberate creation (cf. inventing trains and tracks together). So were we to reject the obscure possibility of atoms giving rise (via natural processes) to conscious beings like ourselves, then we might conclude that the physical world is (probably) a deliberate creation.

But of course, were we to reject the possibility of a creator for its obscurity, we could instead conclude that there must be some way in which atoms do give rise to us. After all, the considerable evidence that the world is Newtonian turned out to only be evidence that it is approximately Newtonian, and so it is not unreasonable to suppose that atoms might also be only approximately how we think of them, deviating from our simplest picture of them in some similarly unforeseeable way.

But similarly, neither would it be unreasonable to suppose that we might have been created (e.g. as below). So, it being completely obscure (at present) how either theism or atheism could be consistent with what we know of the world, it is surely impossible to tell, from the publicly available evidence, which one is most likely. And so although (for various reasons) each of us is actually quite likely to presume one of them, the more objectively rational option is surely agnosticism.

I shall end with an example of one such reason (evolution) for preferring one of those two options (atheism) that seems to be fairly common amongst philosophers (for fairly obvious reasons, e.g. see ScienceBlogs). (This example was suggested by Aaron's comment on the recent post that inspired this post.) Suppose that modern accounts of the evolution of life are (at least approximately) true (as a lot of quite varied evidence indicates). Even so, only such ideas of creation as a too-literal reading of Genesis would consequently be false (and even then, only correspondingly approximately). (In this post I considered one possible motive for creating a world via evolutionary processes, but of course any actual motive is likely to lie well beyond our imaginations.)

Similarly a simplistic, billiard-ball style of materialism is rendered improbable by our self-awareness, but I’m here considering theism vs. atheism, not literalism vs. materialism. It was once said (fallaciously) that incremental evolution could never explain our eyes, but we now have mathematical models of how eyes might arise incrementally. Nonetheless the likelihood of our being unable to provide any such explanation would surely (had it existed) have undermined this reason for preferring atheism. And so we return to the lack of any indication whatsoever of how an evolutionary explanation of consciousnesses such as ours might go.