STROUD:SIGNIFICANCE OF PHILOSOPHICAL SCEPTICISM PAPER

by Barry Stroud

This book raises questions about the nature of philosophy by examining the source and significance of one central philosophical problem: how can we know anything about the world around us?

The author holds that scepticism -- the view that we can have no such knowledge at all -- is the only answer to the problem as traditionally posed. Theories of knowledge that give more encouraging answers are shown to miss or misconstrue the special 'external' or 'philosophical' character of the problem they propose to solve. Several related attempts to characterize the special nature of the philosophical problem -- and thereby the true significance of philosophical scepticism -- are explained and investigated, and a general pattern in the difficulties that arise suggests why no satisfactory unambiguous formulation is to be found. To that extent the very point or purpose of a philosophical theory of knowledge remains obscure.

What is the difference between philosophical questions about human knowledge and scientific or everyday questions about how or whether we know certain things? What, if anything, does philosophical scepticism imply about the knowledge we possess in science and in everyday life? These questions are pursued through discussion and criticism of the views of Descartes, Kant, J.L. Austin, G.E. Moore, R. Carnap, W.V. Quine, and others. A close re-examination of the source of the problem of the external world is recommended, and some promising lines of diagnostic investigation are outlined. - from back cover of book

Genres: Philosophy, Nonfiction

295 pages, Paperback

First published January 1, 1984

About the author

Barry Stroud was a Canadian philosopher.

Reviews

[Tyler · Rating 4 out of 5]

Stroud’s book takes up skepticism not in the sense of ontological doubt, but in the sense of asking how we can ever actually come to know reality. I wasn’t sure that I liked it at first, but it turns out to be an excellent critique that has the unusual quality of getting appreciably better as it goes along.

The author starts with the example from the First Meditation in which Descartes asks how we can know we’re not dreaming. He sticks with this example as a reference point throughout the book because it poses the problem of skepticism in its entirety, and this simplicity makes it easy to follow the subsequent discussion.

Thinkers since Descartes and Hume have proposed ways by which to ground what we think we know in an objective reality. Stroud critiques these thinkers one by one, taking up Moore, Kant, Carnap and Quine. The value this critique brings to philosophy isn’t really the flaws the author discovers in the reasoning of these gentlemen, but the light he sheds on their philosophies aside from skepticism.

Stroud's arguments are good no matter where the reader locates himself in the debate over skepticism. As a realist myself I began to see what the missing ingredient might be in each attempt to ground knowledge in reality, so the steady, in-depth critique the author provides helped me refine or revise my own thinking on the matter.

If a philosophy book can do that then its author has connected with his readership. That makes this one of the better philosophy books I’ve read, and I strongly recommend it to anyone interested in this topic. Stroud drags out the starting discussion of Descartes too long and works the example too finely in later chapters after having already established it. But for that, I would have given this study five stars, which I rarely do for a philosophy book.

The Significance of Philosophical Scepticism turns out to be surprisingly good and it's accessible to general readers of philosophy as well as specialists. Stroud’s critiques are very well done; I’m glad I read this book.

[Alina · Rating 5 out of 5]

I wouldn’t have expected that understanding the claim of philosophical skepticism (e.g., the simulation hypothesis or the possibility of the Cartesian demon) could be so meaningful and fruitful for further thought. Before I would’ve assumed that such philosophical skepticism is silly, something not to be taken seriously, something dreamt up by unsophisticated philosophy boys or sophisticated philosophers but of a different, theological era. Who can take seriously that we all live in a simulation and the external world doesn’t exist? Stroud showed me otherwise. Taking this claim seriously is essential for understanding essential issues at play in any account of knowledge, or what it means for us to know something.

In chapter 1 “The problem of the external world,” Stroud walks us through Descartes’ method in the Meditations and his interpretation of the implicit argument that’s going on in his presentation of his key example, for the skeptical conclusion. Descartes wants a procedure for acquiring knowledge that guarantees that the outcome will be knowledge. It’s futile to attempt to assess every claim we make for whether it is knowledgeable or not. Search for a procedure might at first seem less futile; there could be underlying principles, one might hope, which if a piece of purported knowledge satisfies, we can know a priori that it’ll be knowledgeable. One might propose as such a principle, for example, that knowledge be secured upon a sensory perception.

Descartes, however, shows that this intuitive proposal won’t do. Sensory perceptions under optimal conditions, giving us the best shot at knowledge, are still shaky and unable to guarantee that what we know from their basis will be knowledge. Descartes asks us to consider that he is sitting by a fireplace, where the lighting is bright, and holding a piece of paper. Can he know that the fireplace and the paper is real? These objects are supposed to be representative of anything of the external world; they have no special characteristics that would make our potential relation of knowledge to them not extendable to any other worldly object.

According to Stroud, Descartes argues that a necessary condition for our knowing something is that we have legitimately ruled out the possibility that we are only dreaming, when it appears to us that we are awake, perceiving the world, and thinking about it as actual. As long as the dreaming-possibility lurks around, the fireplace and paper in our hands may not be real, but are just figments of our imagination. If you’re dreaming that something is the case, you don’t thereby know that that’s the case.

One might object that there’s no evidence that we’re always dreaming. But this misses the mark. It’s enough to get Descartes’ position off the ground if we haven’t adequately established that it’s impossible for us to be dreaming right now.

Stroud points out that our best shot at objecting to Descartes is to find an argument for that his requirements for knowledge are too strict; they are unreasonable in some way. In other words, we don’t have to rule out the dreaming-possibility in order to know that something’s the case. A way to motivate this conclusion would be that if Descartes was right, it would be conceptually akin to requiring that in order to know something, you’d need to know the truth of the negation of every single proposition which is incompatible with the claim under consideration. That seems absurd. We don’t require that anyone satisfy that condition.

In chapter 2, “Philosophical skepticism and everyday life” Stroud begins assessing the major positions one could take in attempt to refute Descartes. One position starts off with accusing Descartes for using a sense of the term “knowledge” which is significantly different from the ordinary sense of this term. If someone idiosyncratically defines “doctor” as “a person who can heal any disease in two hours,” one could say that there are no doctors in NYC. That conclusion is not at odds with the fact that there are doctors in NYC because the term “doctor” used across the claims is significantly different in meaning. Stroud motivates that Descartes is in fact using “knowledge” in an ordinary sense. In everyday life, we often follow commonsensical procedures and standards for knowing things, but it turns out that we were wrong in assuming the reliability of these, and they produce false belief. That discovery might motivate us to change our procedure or standards.

Take an example drawn from Thompson Clarke: soldiers might be trained to spot an enemy plane on the basis of the procedure that if a plane has characteristics x, y, and z, then they can know it is this enemy plane. But the soldiers aren’t told that there’s a 1 in 1,000 chance that the plane is in fact not an enemy plane, but some other rare and unthreatening plane. If a soldier ends up apparently spotting an enemy plane by following this procedure which is generally reliable and agreed upon by everyone in his community, but he is unlucky and wrong about it, we can’t say that he knows it’s an enemy plane. It’s a false belief, no matter how good his procedure is and how conscientious he was in following it.

Stroud argues that Descartes runs with a sense of knowledge derived from everyday experiences like this. We know what it’s like to appear to know something but to find out that we were wrong about it. Descartes isn’t talking across the isle, but his view, at least so far as we can tell, actually threatens our commonsense view that we can know that objects of the world exist.

In chapter 3 “G. E. Moore and skepticism: ‘internal’ and ‘external’,” Stroud goes into Moore’s response to philosophical skepticism. Moore infamously gave the argument that he can prove that the external world exist on the basis of his holding up one hand, and then his other hand. In his seeing that his hands exist, he can conclude that the external world exists. Stroud grants that Moore’s argument is conclusive and airtight. But this is contingent upon the assumption that we ought to define “knowledge of an external object” as satisfied by our experiencing or pointing out that object. In effect, Moore refuses to engage with Descartes on his own terms. He refuses to inquire into what it means to know something in the first place, to raise different positions on this matter, and to argue in favor for the position which corresponds to his implicit assumption regarding knowledge of the external world.

In chapter 4 “Internal and external: ‘empirical’ and ‘transcendental’,” Stroud visits Kant’s response to Cartesian skepticism. Kant addresses the critical question which Moore failure to do: What does it mean to know something, and in light of a compelling position of that, how can we know that we do know things? Kant thinks that it is necessary to account for the fact that it appears to us that we know the external world that we commit ourselves to his system of transcendental idealism. Transcendental conditions of experience determine that we’ll experience objects in the world in certain ways, and we can know about objects according to these ways and so be said to properly know of them by virtue of these transcendental conditions of experience also imposing form or structure upon how we can think about the world.

Knowledge of the world is seriously threatened if it turns out to be mediated by something like inference; Descartes thought we can’t have knowledge of the world because the only thing we’ve got which is unmediated are our sensory impressions, which establish only the mere appearances of things, rather than their existence. In effect, Kant shows that knowledge of the world is unmediated and rather granted to us by virtue of the transcendental conditions of experience which make up our mind.

Stroud addresses how at first glance, it’s pretty bizarre to refute empirical idealism (a major consequence of philosophical skepticism) by committing to another form of idealism, transcendental idealism. Is the latter supposed to be less worry-inducing or more satisfying than the former, even though both are varieties of idealism? It’s supposed to be. For Kant, Descartes has overstepped the boundaries of what makes sense to say or think about. His very notion of the external world as not existing is incoherent on Kant’s picture; we’re determined or fated to encounter this world on his picture. But as a whole, Stroud thinks, Kant’s answer to philosophical skepticism isn’t satisfying. Kant’s picture is not conclusive, to say the least, and it doesn’t guarantee that we have knowledge of the world in a familiar sense. Kant is revisionary regarding what it means to know the world.

In chapter 5 “Internal and external: meaningful and meaningless,” Stroud addresses verificationism or logical positivism as another potential answer to Cartesian skepticism. This view fails for similar reasons as Kant’s. Verificationism is the thesis that a statement is meaningful or coherent only if it can be assessed empirically (and so two statements, even if they appear to be different conceptually, are in fact identical in meaning if they’d be supported or refused by the same empirical evidence would). This implies that there could be different vocabularies or paradigms which are equally true, insofar as they’re supported by empirical evidence all the same. Stroud points out that this view invites idealism; who’s to say that there’s a world out there if all we’re getting is empirical data which can support different beliefs? Thinkers like Carnap miss the mark; to play by his own rules of verificationism, any possible experience could make a belief in the existence of the world any more warranted than a belief in its nonexistence, assuming that the dream-possibility continues to hold, which the verificationist hasn’t addressed at all.

In chapter 6 “Naturalized epistemology” Stroud addresses Quine’s response to Cartesian skepticism. Science shows us that the external world exists, and that’s all we can ask for, according to Quine. Quine would say that Descartes is wrong to propose that we could imagine what’s going on in our experience of apparently knowing things from some “external” all-knowing point of view. That point of view is conceptually incoherent, according to Quine; theoretical posits which are okay to keep to are those which simplify our (scientific) accounts of the world, and that theoretical posit of such an external point of view doesn’t help us in any way. Stroud argues that Quine also misses the mark and fails to refute Descartes. Quine’s conception of knowledge is even committed to skepticism: in order to ensure that somebody’s belief isn’t merely coincidentally true, and so is a matter of knowledge, we must first know how the world stands, and the processes that person went through in arriving at their knowledge. But Quine acknowledges that our knowledge of the world and somebody’s psychology are limited. Sensory stimuli is under-determined relative to such knowledge. The dream-possibility continues to hold strong; we could be wrong about the world or someone’s psychology.

The overall lesson in Stroud’s book is that the most promising, maybe only promising angle into challenging philosophical skepticism is to show that Descartes’ starting assumption that a necessary condition of knowledge is that we’ve ruled out the dream-possibility is a bad one. To do this, one would have to show that there’s something fantastical or incoherent about our capacity to imagine how the world could be from an “external” point of view—a point of view that breaks off from all our experience of our being in the world, and the world’s being real. Stroud has shown, however, that the danger of embarking on that project is to fall into some other variety of idealism, as Kant, Carnap, and even Quine did. To say that we can’t coherently talk about this distanced, external point of view is motivated by each of them by appeal to how our experiences of things exhausts all there is to know or carves out the limits of intelligibility in some way. That’s a recipe for idealism: our own experience takes front stage in setting the limits upon knowledge. Stroud doesn’t solve this issue for us. But he clears the ground for more level-headed proposals in the future.

It was inspirational to see Stroud’s arguments. He is sensitive to whether a supposed objection to a certain view agrees to the terms of that view or not. And if not, then that objection can be susceptible to its premises being undermined by the lights of that view. This is a style of argument I don’t often see. Often, philosophers will respond to a position without being reflective upon whether they the implicit terms (how a word is used) are agreed upon or not. But maybe this sort of care is common in contemporary works on history of philosophy; I don’t read too much of this genre.

I feel like Stroud got at something very deep which might be generalizable to other philosophical debates, even those not in epistemology. There’s something compelling about the form of this book and his argument, regarding how Stroud shows that a repudiation of knowledge of the external world helps us understand all of the essential but elusive elements at play in what it means to know the external world. I’m not sure how to articulate this idea further at the moment, however. Maybe the generalizable form is that proposing skepticism about some commonsense issue helps us get more fine-grained about that issue. Or, maybe it’s that arguments that attack the presumed central concepts of a debate are crucial for addressing that debate, even if it seems to be orthogonal or too distanced to be useful.

I’m also curious about how the particular debate of self-knowledge might interact with this issue of skepticism of the external world. In order for Descartes’ proposal to get off the ground, for example, it seems that we need to assume that we know what we’re thinking or experiencing. It’s integral to Descartes’ account that we can know that we experience sensory impressions at the outset, rather than objects in the world. An alternative picture could be offered by thinkers like Schopenhauer, who say that all we have immediate “access” to is something that is not yet conceptually determinate (for him it was “the will”)—and as soon as we conceptualize it as mere sensory impressions (as a notion which permits this entity to be independent of external objects) or external objects, we’re now on shakier territory. I’m not sure whether this line of attack would work, however. It seems self-evident that we can know our own thoughts, and maybe that’s the foundation that Descartes could appeal to for making sense of the notion of sensory impressions; sensory impressions aren’t individuated on the basis of experience (which is perhaps ambiguous or indeterminate relative to judgments we can form of an experience), but they can be understood as “fully internal” off the model of our having thoughts. But maybe the same point of the shakiness of self-knowledge could be pressed on the issue of our having thoughts? We have thought, for sure, but that doesn’t entail that we can know our own thoughts, or what our thought is about, at least according to certain implicit standards of knowledge.

Maybe I’m just being misled here, however. It’s not about self-knowledge, but it’s just about the propositions we’re thinking about. There are concepts to make intelligible the proposal that our experience hands us sensory impressions at the “most immediate” level, as opposed to external objects. To challenge that proposal ought not proceed on the basis of questioning whether we can know our own thoughts and experiences, but it should rather proceed in evaluating the content of that proposal, namely, whether it is the case that we most directly encounter sensory impressions as opposed to external objects; or, it should proceed in analyzing these concepts employed. I’m not sure.

I wonder how the two relate: skepticism of knowledge based in whether we can know the existence of external objects vs. in whether we can know what we’re thinking, believing, or experiencing. One key difference, I suspect, is that the sort of external object that gets talked about under philosophical skepticism either existence or don’t (e.g., a piece of paper exists or it doesn’t). In contrast, as soon as we get into matters of whether some belief or desire we believe we have ‘exists,’ a more appropriate question arises immediately: it’s less about whether a particular belief or desire we’ve named exists, but more about that there’s something going on which explains our life and behavior, and we can be skeptical about whether it’s best “modeled” by the thus named belief or desire. An analogous concern doesn’t arise in philosophical skepticism of the external world; if the world doesn’t exist, it doesn’t seem that philosophers are very interested in what is going on instead (and rather they take for granted the explanation would be based in some form of idealism or solipsism). I feel confused at the moment regarding this. I’d like to think more.

[Seth · Rating 1 out of 5]

[Review based on the discussion of Descartes, written lest I ever feel tempted to read the rest]

Stroud writes like he's Goodharting a page quota. This would be merely annoying, but he's also guilty of some egregiously bad argumentation: At one point, he claims to be accepting, for the sake of argument, that there could in principle be a test that rules out the possibility that one is dreaming, while actually denying that possibility. For what could such a test consist in but the presence of some sense data that dreaming could not produce? And considering the low fidelity of dreaming relative to wakefulness, it does seem possible, at least in principle, that there could be such a test. That is, surely, the basis for the common wisdom that one should inflict a little pain on oneself to be assured of wakefulness. Stroud, bizarrely, just asserts that it's obvious that there is no sense data that could not be present in a dream and focuses his supposed acceptance for the sake of argument on tests that are easier to rule out. The icing on the cake is that he doesn't even need this unargued bad assumption - where's the evil genius (or, in the modern parlance, the brain in a vat), which provides stronger support for the skeptical conclusion? Conspicuously absent, for no apparent reason.

[G9 · Rating 4 out of 5]

Despite some flaws (sometimes being too repetitive on certain ideas), this is one of the best introductory texts focusing on the significance of philosophical skepticism. Chapter 1, 2 and 7 are especially good.

Stroud's skeptical pronouncement boils down a conditional claim: if our knowledge about the external world is possible only if the dream-possibility can be eliminated, then philosophical skepticism is correct. The whole book is dedicated to show how each position throughout the history of philosophy (Moore, Kant, Carnap, Quine, Cavell and Clark) falls short in trying to undermine this skeptiacl thesis.
In so doing, Stround concludes, or rather, suggests that skepticism is the ultimate correct view on our epistemic condition in relation to the objective world.

[Phillip · Rating 5 out of 5]

Here is a companion from my undergraduate days. It is a little difficult but does a fantastic job of arguing why the question of whether or not the world exist independent of our sense experience of it is an important question. He does not argue for a solution. He presents the different possible strategies that are out there.

[Kimberly · Rating 5 out of 5]

A useful introductory text to Philosophical Scepticism. I'm torn between 4.5 and 5 stars, because I wanted more discussion of the influences responsible for 20th Century cultural divergences in methodology. This book is written for a wide audience, which is not always easy to do while keeping the work appealing to a professional philosopher. This book succeeds.

[Jordan · Rating 3 out of 5]

Interesting book from this very moderate sceptic; Skipped a few chapters, to get onto his more recent work, but enjoyable nonetheless, particularly for his sceptical acceptance of Descartes, whom nearly every other philosopher desperately tries to avoid...

[Raphael Rosen · Rating 5 out of 5]

I love Barry Stroud!

[Blakely · Rating 4 out of 5]

Exquisite analysis of the structure of skeptical problems.

[Chris · Rating 5 out of 5]

This is not much of a review, but this book made me pursue epistemology.

[Alex Tsiatsos · Rating 4 out of 5]

A fantastically patient account of scepticism countering challenges to scepticism throughout modern philosophy. I don't remember if it was convincing, ultimately. I look forward to reading it again.

[Reed · Rating 4 out of 5]

Anyone doing academic research in epistemology and would like to gain a clearer understanding of the nature and implications of skeptical argumentation should definitely check this one out!

[zimu]

Chapter read: Problem of the External World