Two major arguments have been advanced for the claim that there is a transmission failure in G.E. Moore’s famous proof of an external world. The first argument, due to Crispin Wright, is based on an epistemological doctrine now known as ‘conservatism’. Proponents of the second argument, like Nicholas Silins, invoke probabilistic considerations, most important among them Bayes’ theorem. The aim of this essay is to defend Moore’s proof against these two arguments. It is shown, first, that (...) Wright’s argument founders because one of its premises, viz., conservatism, invites scepticism and must therefore be rejected. Then the probabilistic argument is challenged, not because its formal part is dubious, but rather on the grounds that it incorporates an unconvincing philosophical claim as an implicit premise. Finally, the two most promising objections to dogmatism—the negation of conservatism—are repudiated. (shrink)

In the last few years there has been a resurgence of interest in Moore’s Proof of the existence of an external world, which is now often rendered as follows:1 (I) Here’s a hand (II) If there is a hand here, there is an external world Therefore (III) There is an external world The contemporary debate has been mostly triggered by Crispin Wright’s influential—conservative —“Facts and certainty” and further fostered by Jim Pryor’s recent—liberal—“What’s wrong with Moore’s argument?”.2 This (...) debate is worth surveying with care because—so I shall contend—it will help us see that, in fact, it allows for an important view that, so far, hasn’t been explicitly considered. The critical survey will be the task of the next two sections, while, in the remaining.. (shrink)

In the last few years there has been a resurgence of interest in Moore’s Proof of the existence of an external world, which is now often rendered as follows:1 (I) Here’s a hand (II) If there is a hand here, there is an external world Therefore (III) There is an external world The contemporary debate has been mostly triggered by Crispin Wright’s influential—conservative —“Facts and certainty” and further fostered by Jim Pryor’s recent—liberal—“What’s wrong with Moore’s argument?”.2 This (...) debate is worth surveying with care because—so I shall contend—it will help us see that, in fact, it allows for an important view that, so far, hasn’t been explicitly considered. The critical survey will be the task of the next two sections, while, in the remaining.. (shrink)

Two major arguments have been advanced for the claim that there is a transmission failure in G. E. Moore’s famous proof of an external world. The first argument, due to Crispin Wright, is based on an epistemological doctrine now known as “conservatism.” Proponents of the second argument, like Nicholas Silins, invoke probabilistic considerations, most important among them Bayes’ theorem. The aim of this essay is to defend Moore’s proof against these two arguments. It is shown, first, (...) that Wright’s argument founders because one of its premises, viz, conservatism, invites skepticism and must therefore be rejected. Then the probabilistic argument is challenged, yet not because its formal part is dubious, but rather on the grounds that it incorporates as an implicit premise an unconvincing philosophical claim. Finally, the most promising objection to dogmatism – understood here as the negation of conservatism – is repudiated. (shrink)

I argue that if we allow that Moore’s Method, which involves taking an ordinary knowledge claim to support a substantive metaphysical conclusion, can be used to support Moore’s proof an external world, then we should accept that Moore’s Method can be used to support a variety of incompatible metaphysical conclusions. I shall refer to this as “the problem of many proofs”. The problem of many proofs, I claim, stems from the theory-ladenness of perception. I shall argue (...) further that this plethora of proofs for incompatible positions leads to a darker form of skepticism, one which maintains that each of the dogmatic views is probably false. We will conclude by considering various ways a Moorean might respond to these difficulties. (shrink)

SummaryThere is an enormous literature on Moore's so‐called “proof”per se, but practically nothing has been written on the distinctions upon which the proof is bases, such as “being presented in space” and “being met with in space”. These are crucial to the argument, since Moore wishes to draw the line between the external and internal world via such distinctions. The author argues that these distinctions themselves crucially depend on a point that Moore does not argue for, but assumes, (...) namely that afterimages, negative after‐images, some sense‐data and pains are private to those that have them, and that two different people cannot sense numerically the same after‐images, pains etc. The author shows that this assumption is nonsense and that the entire proof, based upon it, therefore fails. (shrink)

You have hands, but does it follow that there’s an external material world? Moore thought so. However, we argue that this is a mistake. We defend the Ecumenical View, on which ordinary object terms like “hands” are metaphysically ecumenical, akin to the way that terms like “table” are physically ecumenical: just as there are wooden, metal, or plastic tables, so too there can be material, virtual, or immaterial hands. Moore’s position, however, is metaphysically sectarian: the semantics of “hands” requires (...) a materialist metaphysics. Moore’s proof fails not because it displays bad epistemology but because of its problematic commitment to sectarian metaphysics. We conclude with some explorative thoughts on how the Ecumenical View bears on common sense epistemology and a possible equivocation in our understanding of the premises of Moore’s argument. (shrink)

In the recent literature on Moore's Proof of an external world, it has emerged that different diagnoses of the argument's failure are prima facie defensible. As a result, there is a sense that the appropriateness of the different verdicts on it may depend on variation in the kinds of context in which the argument is taken to be a move, with different characteristic aims. In this spirit, Martin Davies has recently explored the use of the argument within two different (...) epistemic projects called respectively ‘deciding what to believe’ and ‘settling the question’. Depending on which project is in hand, according to Davies, the diagnoses of its failure—if indeed it fails—will differ. I believe that, by introducing the idea that the effectiveness of a valid argument may be epistemic project-relative, Davies has pointed the way to an important reorientation of the debates about Moore's Proof. But I wish to take issue with much of the detail of his proposals. I argue that Davies's characterization of his two projects is misleading (§1), and his account of their distinction defective (§2). I then canvass some suggestions about how it may be improved upon and about how further relevant kinds of epistemic projects in which Moore's argument may be taken to be a move can be characterized, bringing out how each of these projects impinges differently on the issue of the Proof's failure and of its diagnosis (§§3 and 4). In conclusion (§5) I offer an overview of the resulting terrain. (shrink)

Moore's proof of an external world is a piece of reasoning whose premises, in context, are true and warranted and whose conclusion is perfectly acceptable, and yet immediately seems flawed. I argue that neither Wright's nor Pryor's readings of the proof can explain this paradox. Rather, one must take the proof as responding to a sceptical challenge to our right to claim to have warrant for our ordinary empirical beliefs, either for any particular empirical belief we might (...) have, or for belief in the existence of an external world itself. I show how Wright's and Pryor's positions are of interest when taken in connection with Humean scepticism, but that it is only linking it with Cartesian scepticism which can explain why the proof strikes us as an obvious failure. (shrink)

Moore’s proof of an external world is a piece of reasoning whose premises, in context, are true and warranted and whose conclusion is perfectly acceptable, and yet immediately seems flawed. I argue that neither Wright’s nor Pryor’s readings of the proof can explain this paradox. Rather, one must take the proof as responding to a sceptical challenge to our right to claim to have warrant for our ordinary empirical beliefs, either for any particular empirical belief we (...) might have, or for belief in the existence of an external world itself. I show how Wright’s and Pryor’s positions are of interest when taken in connection with Humean scepticism, but that it is only linking it with Cartesian scepticism which can explain why the proof strikes us as an obvious failure. (shrink)

Moore’s proof consists of the inference of both “Two hands exist at this moment” and “At least two external objects exist at this moment” from the premise “Here is one hand and here is another.” The paper claims that the proof succeeds in refuting both idealism (“There are no external objects”) and skepticism (“Nobody knows that there are external objects”). The paper defends Moore’s proof against the following objections: Idealism does not deny that there is (...) an external world so Moore’s proof is beside the point; Moore may be mistaken about the premise; Moore has failed to prove the premise; Moore has failed to show how he knows the premise; the proof leads to an infinite regress; the proof begs the question because the premise assumes what needs to be proved; the premise depends upon a shaky inference; the premise rests upon evidence of the senses and thus begs the question; the proof fails to convince the skeptic. (shrink)

According to Jim Pryor’s dogmatism, if you have an experience as if P, you acquire immediate prima facie justification for believing P. Pryor contends that dogmatism validates Moore’s infamous proof of a material world. Against Pryor, I argue that if dogmatism is true, Moore’s proof turns out to be non-transmissive of justification according to one of the senses of non-transmissivity defined by Crispin Wright. This type of non-transmissivity doesn’t deprive dogmatism of its apparent antisceptical bite.

The existence of objects external to the mind is a proof-condition for the type of object demonstration Moore provided in his famous lecture. Affirming the existence of objects external to the mind is just a way of saying that one person can show (present, demonstrate) something to another to prove it is so, to prove it exists, Demonstrations like that are conclusive and immune to scepticism.

RRecently, much work has been done on G.E. Moore’s proof of an external world with the aim of diagnosing just where the Proof ‘goes wrong’. In the mainstream literature, the most widely discussed debate on this score stands between those who defend competing accounts of perceptual warrant known as dogmatism and conservativism. Each account implies a different verdict on Moore’s Proof, though both share a commitment to supposing that an examination of premise-conclusion dependence relations will (...) sufficiently reveal what’s wrong with the Proof. Parallel to this debate on Moore stands perhaps an equally interesting debate within which the Proof is critiqued as it stands in the context of the skeptical debate. On this score, Michael Fara and Ernest Sosa have weighed in with a markedly different take on Moore’s anti-skeptical ambitions and on the nature of skeptical challenges more generally. The aim of this paper will be to critically evaluate these two very distinct strands of recent work on Moore’s Proof. Part I of the paper will focus on the mainstream debate, and in Part II of the paper, I’ll focus on the parallel debate about skepticism. My critical discussion will be aimed throughout at showing how the various proposals I’ve taken as representative of these two parallel debates surrounding Moore’s Proof ultimately fall short—each for different reasons—of what a satisfactory diagnosis of the Proof would require. (shrink)

The current standard interpretation of Moore’s proof assumes he offers a solution to Kant’s famously posed problem of an external world, which Moore quotes at the start of his 1939 lecture “Proof of an External World.” As a solution to Kant’s problem, Moore’s proof would fail utterly. A second received interpretation imputes an aim of refuting metaphysical idealism that Moore’s proof does not at all achieve. This study departs from received interpretations to credit (...) the aim Moore announced for the proof Moore performed in his 1939 lecture. Moore’s aim was to impose a counter-example to a stated presupposition of Kant’s problem of an external world. Moore’s lecture nevertheless neither endorses a replacement for Kant’s problem nor acknowledges that an immediate implication of achieving his announced aim would subvert Kant’s famously posed problem of an external world. (shrink)

A common view about Moore’s Proof of an External World is that the argument fails because anyone who had doubts about its conclusion could not use the argument to rationally overcome those doubts. I agree that Moore’s Proof is—in that sense—dialectically ineffective at convincing an opponent or a doubter, but I defend that the argument (even when individuated taking into consideration the purpose of Moore’s arguing and, consequently, the preferred addressee of the Proof) does (...) not fail. The key to my defence is to conceive the Proof as addressed to subjects with a different epistemic condition. To sustain this view I formulate some hypothesis about the common general purpose of arguing and I defend that it can be fulfilled even when the addressee of an argument is not someone who disbelieves or doubts its conclusion. (shrink)

We develop a reading of Moore’s “Proof of an External World” that emphasizes the connections between this paper and Moore’s earlier concerns and strategies. Our reading has the benefit of explaining why the claims that Moore advances in “Proof of an External World” would have been of interest to him, and avoids attributing to him arguments that are either trivial or wildly unsuccessful. Part of the evidence for our view comes from unpublished drafts which, we believe, (...) contain important clues concerning Moore’s aims and intent. While our approach to PEW may be classified alongside other broadly "metaphysical" readings, we believe that a proper recognition of the continuity in Moore’s philosophical concerns and strategies across his philosophical career shows that the customary distinction between "epistemological" and "metaphysical" interpretative approaches to PEW is at best superficial. (shrink)

A new reading of G.E. Moore's ‘Proof of an External World’ is offered, on which the Proof is understood as a unique and essential part of an anti-sceptical strategy that Moore worked out early in his career and developed in various forms, from 1909 until his death in 1958. I begin by ignoring the Proof and by developing a reading of Moore's broader response to scepticism. The bulk of the article is then devoted to understanding what role (...) the Proof plays in Moore's strategy, and how that role is played. (shrink)

Much has been said about Moore’s proof of the external world, but the notion of proof that Moore employs has been largely overlooked. I suspect that most have either found nothing wrong with it, or they have thought it somehow irrelevant to whether the proof serves its antiskeptical purpose. I show, however, that Moore’s notion of proof is highly problematic. For instance, it trivializes in the sense that any known proposition is provable. This undermines (...) Moore’s proof as he conceives it since it introduces a skeptical regress that he goes at length to resist. I go on to consider various revisions of Moore’s notion of proof and finally settle on one that I think is adequate for Moore’s purposes and faithful to what he says concerning immediate knowledge. (shrink)

Suppose one has a visual experience as of having hands, and then reasons as follows: I have hands, If I have hands an external world exists; An external world exists. Suppose one’s visual experience gives one defeasible perceptual warrant, or justification, to believe – that is, one’s experience makes it epistemically appropriate to believe . And suppose one comes to believe on the basis of this visual experience. The conditional premise is knowable a priori. And can be established by modus (...) ponens inference. If one reasons thus, say one’s engaged in -reasoning. What, if anything, is wrong with -reasoning? I consider two prominent responses to this question – the dogmatists’ and Crispin Wright’s. Each finds fault in -reasoning, but on different grounds. I argue Wright’s response faces a problem which is standardly only taken to be faced by dogmatists. (shrink)

This paper argues that we should reject G. E. Moore’s anti-skeptical argument as it is presented in “Proof of an External World.” However, the reason I offer is different from traditional objections. A proper understanding of Moore’s “proof” requires paying attention to an important distinction between two forms of skepticism. I call these Ontological Skepticism and Epistemic Skepticism. The former is skepticism about the ontological status of fundamental reality, while the latter is skepticism about our empirical (...) knowledge. Philosophers often assume that Moore’s response to “external world skepticism” deals exclusively with the former, not the latter. But this is a mistake. I shall argue that Moore’s anti-skeptical argument targets an ontological form of skepticism. Thus, the conclusion is an ontological claim about fundamental reality, while the premises are epistemic claims. If this is correct, then the conclusion outstrips the scope of its premises and proves too much. (shrink)

It is widely assumed that G. E. Moore was either oblivious or indifferent to circularity worries surrounding his enigmatic proof of an external world. I argue that this assumption is false. Drawing on unpublished archival evidence and overlooked passages in Moore’s posthumously published lectures, I provide, for the first time, an account of Moore on circular proof. I show that, as early as 1928–29 and as late as 1938–39, Moore identified an “important” and “unimportant” sense of begging (...) the question (epistemic circularity and premise circularity, respectively) and maintained that a genuine proof should avoid both forms. Curiously, however, this standard is not upheld in his 1939 “Proof,” where this “important” sense is conspicuously absent from Moore’s discussion. This discrepancy raises an interpretative puzzle: Why does Moore’s standard for proof change? I provide an answer and explore its philosophical implications, clarifying the paradoxical nature of the proof and re-diagnosing the sense of intellectual dissatisfaction experienced by many commentators. (shrink)

G.E. Moore, more than either Bertrand Russell or Ludwig Wittgenstein, was chiefly responsible for the rise of the analytic method in twentieth-century philosophy. This selection of his writings shows Moore at his very best. The classic essays are crucial to major philosophical debates that still resonate today. Amongst those included are: * A Defense of Common Sense * Certainty * Sense-Data * External and Internal Relations * Hume's Theory Explained * Is Existence a Predicate? * Proof of an External (...) World In addition, this collection also contains the key early papers in which Moore signals his break with idealism, and three important previously unpublished papers from his later work which illustrate his relationship with Wittgenstein. (shrink)

(2008). Neither Dogma nor Common sense: Moore's confidence in his ‘proof of an external world’1. British Journal for the History of Philosophy: Vol. 16, No. 1, pp. 163-195.

G.E. Moore, more than either Bertrand Russell or Ludwig Wittgenstein, was chiefly responsible for the rise of the analytic method in twentieth-century philosophy. This selection of his writings shows Moore at his very best. The classic essays are crucial to major philosophical debates that still resonate today. Amongst those included are: * A Defense of Common Sense * Certainty * Sense-Data * External and Internal Relations * Hume's Theory Explained * Is Existence a Predicate? * Proof of an External (...) World In addition, this collection also contains the key early papers in which Moore signals his break with idealism, and three important previously unpublished papers from his later work which illustrate his relationship with Wittgenstein. (shrink)

G. E. Moore was one of the most interesting and influential philosophers of the first half of the twentieth century. This selection of his writings makes the best of his work once again available, and also includes previously unpublished writings. Moore's first published writings, represented in this collection by his papers "The Nature of Judgment" and "The Refutation of Idealism," contributed decisively to the break with idealism which led to the development of analytic philosophy. Moore went on to develop his (...) own style, which combined a defense of the common sense view of the world with a controversial analysis of the content of this view. Also included is Moore's famous "Proof of an External World," which marked a return late in his career to the critique of idealism. Other papers address perception and important issues in logical theory. The collection ends with three new pieces which illustrate Moore's relationship with Wittgenstein. In these pieces Moore discusses his "paradox" whichso fascinated Wittgenstein; the nature of our knowledge of our own sensations; and Malcolm's views about doubt and knowledge which were themselves inspired by Wittgenstein. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Notes and Discussions Moore's Moral Rules Since the publication of Tom Regan's Bloomsbury'sProphet:G. E. Moore and the Development of His Moral Philosophy (Philadelphia: Temple University Press, 1986) a controversy has arisen concerning Moore's practical ethical theory. According to Regan, Moore was Bloomsbury's "liberator" whose Principia Ethica provided the rationale for ignoring the conventional rules of morality (except for "a very few") in favor of personal choice. This, says Regan, (...) is the "central thesis" of Principia. Against Regan's interpretation Avrum Stroll (JHP 26:3, July 1988: 5o4-5o5) insists that Regan's evidence is "exiguous" and that "a careful reading of [Principia's] Chapter 5 shows that Moore argues that.., we ought alwaysto follow the dictates of common morality." In a similar vein Thomas Baldwin (Mind, Jan. 1988:129-33 ) claims that Regan's thesis rests upon "a misreading of a passage in [Chapter 5 of] Principia Ethica" and yields an interpretation of Moore which asserts "the opposite" of what Moore actually says. In what follows I wish to examine the crucial passages of Principia to determine just what Moore's view is and whether Regan is indeed guilty of misreading. Because of the severe limitations regarding our knowledge of cause and effect, the most, according to Moore, that we can obtain in practical ethics, is knowledge that "one kind of action will generallyproduce better effects than another."' And this leads him to consider the justification of the rules of common morality. On pp. 162-63 Moore does say that of "any rule which is generally useful, we may assert that it ought alwaysto be observed... [and that] though we may be sure that there are cases where the rule should be broken, we can never know which those cases are, and ought, therefore, never to break it." But, as the text reveals, this assertion is preceded by the hypothesis "/f/t is certainthat in a large majority of cases the observance of a certain rule is useful" (162, emphasis added). Indeed, Moore's discussion on pp. 162-64 is focused explicitly on "those actions as to which some general rule is certainlytrue'' (162, emphasis added). So what sorts of rules are those? Moore has already said on p. 16o: "it seems possible to prove a definite utility in most of those which are in general both recognised and practised." And just which rules are both recognized and practiced? They are those which he frequently refers to as "the rules most universally recognised by Common G. E. Moore, PrincipiaEthica(Cambridge: Cambridge University Press, 1962), 155. Hereafter cited by page number alone. [595] 596 JOURNAL OF THE HISTORY OF PHILOSOPHY 98:4 OCTOBER 199 ~ Sense" (156-57). He says that for "most" of these their general utility can be "established " and is "capable of proof" (t 55-56). His examples are rules concerning murder, respect for property, industry, temperance, and keeping promises (156-57). ~ Now, assuming that what is established or capable of proof is, in Moore's parlance, "certain," and taking the moral rules of Common Sense to be roughly what Stroll means by "common morality," we can see that StroU's assertion that "Moore argues that.., we ought always to follow the dictates of common morality" is not quite correct. At most Moore seems to be saying that we ought always to follow the dictates of "most" of common morality. But even this is too strong, because Moore's phrase "the rules most universally recognised by Common Sense" suggests that Common Sense morality may include rules which are not "universally recognised," and hence, less than certain. Also, Moore says that "a great part of ordinary moral exhortation.., consists in the advocating of rules not generally practised." If Moore holds that common morality does indeed inclucJe a significant portion of rules which are neither universally recognized nor generally practiced, then even the claim that he argues that we ought always to follow most of its dictates seems questionable. As Regan observes, Moore goes on in Chapter 5 to say some things which confirm our doubts and make it very difficult to accept Strolrs assertion, even in its modified form. For Moore seems to say... (shrink)

Once, G. E. Moore scorned the “common point of view which takes the world of experience as ultimately real.” The argument Moore followed to this sceptical conclusion in his fledgling 1897 fellowship dissertation was a legacy from Kant's Antinomies. By 1899 Moore had renounced idealist conclusions; he set out both to disengage from Kantian arguments and to reconcile with “the world of experience.” Moore's work for a stable realist basis for knowledge to fulfil both aims occupied his most famous argument, (...) in his 1939 lecture “Proof of an External World.” Moore himself is sometimes supposed to have thought the argument of this masterwork unsatisfactory where it treats a traditional sceptical puzzle posed by dreaming. Critics, including Wittgenstein, have portrayed Moore's best reply to philosophical scepticism as dogmatic mere assertion, unresponsive or as ineffectual as sheer handwaving. However, these critics rate Moore's success against scepticism based on interpretations of “Proof of an External World” that neglect its part in Moore's campaign against Kant. Consequently, some potentially pivotal questions — which in this study I merely broach — remain wide open; for example, why in presenting his famous 1939 proof did Moore state that its purpose was to refute what “Kant declares to be his opinion, that there is only one possible proof of the existence of things outside of us”? And why did Moore explicitly reject the formula for posing philosophical scepticism in which Kant famously proclaimed this problem “a scandal to philosophy”? (shrink)

What gave rise to Ernst Zermelo's axiomatization of set theory in 1908? According to the usual interpretation, Zermelo was motivated by the set-theoretic paradoxes. This paper argues that Zermelo was primarily motivated, not by the paradoxes, but by the controversy surrounding his 1904 proof that every set can be wellordered, and especially by a desire to preserve his Axiom of Choice from its numerous critics. Here Zermelo's concern for the foundations of mathematics diverged from Bertrand Russell's on the one (...) hand and from Felix Hausdorff's on the other. (shrink)

The question of realism - that is, whether God exists independently of human beings - is central to much contemporary theology and church life. It is also an important topic in the philosophy of religion. This book discusses the relationship between realism and Christian faith in a thorough and systematic way and uses the resources of both philosophy and theology to argue for a Christocentric narrative realism. Many previous defences of realism have attempted to model Christian belief on scientific theory (...) but Moore argues that this comparison is misleading and inadequate on both theological and philosophical grounds. In dialogue with speech act theory and critiques of realism by both non-realists and Wittgensteinians, a new account of the meaningfulness of Christian language is proposed. Moore uses this to develop a regulative conception of realism according to which God's independent reality is shown principally in Christ and then through Christian practices and the lives of Christians. (shrink)

In 1887 Georg Cantor gave an influential but cryptic proof of theimpossibility of infinitesimals. I first give a reconstruction ofCantor's argument which relies mainly on traditional assumptions fromEuclidean geometry, together with elementary results of Cantor's ownset theory. I then apply the reconstructed argument to theinfinitesimals of Abraham Robinson's nonstandard analysis. Thisbrings out the importance for the argument of an assumption I call theChain Thesis. Doubts about the Chain Thesis are seen to render thereconstructed argument inconclusive as an attack on (...) the infinitelysmall. (shrink)

Introduction A Brief Conceptual Framework for Biology PART ONE: UNDERSTANDING NATURE 1. The Antecedents of Scientific Thought Animism, Totemism, and Shamanism The Paleolithic View Mesopotamia Egypt 2. Aristotle and the Greek View of Nature The Science of Animal Biology The Parts of Animals The Classification of Animals The Aristotelian System Basic Questions 3. Those Rational Greeks? Theophrastus and the Science of Botany The Roman Pliny Hippocrates, the Father of Medicine Erasistratus Galen of Pergamum The Greek Miracle 4. The Judeo-Christian Worldview (...) The Bishop of Hippo Scholastic Thought Islamic Science Books on Beasts Antecedents of a Revolution 5. The Revival of Science Andreas Vesalius and the Study of Structure William Harvey and the Study of Function Sir Francis Bacon’s Great Instauration Induction, Hypothesis, Deduction The Very Small--Animalcules Robert Hooke and the Discovery of Cells 6. Figur’d Stones and Plastick Virtue Marine Life on Mountain Tops? Figured Stones of Unknown Creatures Baron Cuvier Quarries of the Paris Basin Catastrophism and Uniformitarianism William Smith and the Geological Column Understanding Nature in 1850 PART TWO: THE GROWTH OF EVOLUTIONARY THOUGHT 7. The Paradigm of Evolution First Questions The Paradigm of Natural Theology First Answers 8. Testing Darwins Hypotheses Have Life Forms Changed over Time? Do Species Evolve into Different Species over Time? Has There Been Time Enough for Evolution? Is Natural Selection the Mechanism of Change? The Genetic Basis of Natural Selection Accounting for the Diversity of Life 9. In the Light of Evolution Comparative Anatomy Embryonic Development Classification Microstructure Molecular Processes 10. Life over Time The Origin of Life The Rise of Multicelled Organisms What Is a Phylum? Burgess Shale Metazoans Early Evolution of the Vertebrates The Age of Dinosaurs Birds, Mammals, and Flowering Plants The Rancho La Brea Tar Pits Human Evolution The Role of Extinction in Evolution PART THREE: CLASSICAL GENETICS 11. Pangenesis What Is the Question? Hippocrates and Aristotle The Darwinian Answer Assembling the Data Formulating the Hypothesis by Induction Galton’s Rabbits 12. The Cell Theory The Discovery of Cells: Robert Hooke Schwann and Cells in Animals Gametes as Cells Omnis cellula e cellula? The Technology of Cell Research 13. The Hypothesis of Chromosomal Continuity The Ephemeral Nucleus Schneider, Flemming, and Cell Division The Chromosomes and inheritance Gamete Formation Fertilization 14. Mendel and the Birth of Genetics Model for Monohybrid Crosses Model for Dihybrid Crosses Mendel’s Laws Initial Opposition to Mendelism 15. Genetics + Cytology: 1900-1910 Sutton’s Model The Cytological Basis of Mendel’s Laws Boveri and Abnormal Chromosome Sets Variations in Mendelian Ratios The Discovery of Sex Chromosomes 16. The Genetics of the Fruit Fly Morgan’s First Hypothesis Morgan’s Second Hypothesis The Fly Room Linkage and Crossing-Over The Cytological Proof of Crossing-Over Mapping the Chromosomes The Final Proof The Determinants of Sex The Conceptual Foundations of Classical Genetics 17. The Structure and Function of Genes One Gene, One Enzyme The Substance of Inheritance The Watson-Crick Model of DNA Genes and the Synthesis of Proteins The Genetic Code PART FOUR: THE ENIGMA OF DEVELOPMENT 18. First Principles The Peripatetic Stagirite The Death and Rebirth of Scientific Thought Harvey and Malpighi A Two-Millennial Summing Up Preformation versus Epigenesis 19. The Century of Discovery Von Baer’s Discovery of the Mammalian Ovum Darwin’s Contribution to Embryology Haeckel and Recapitulation 20. Descriptive Embryology Germ Layers The External Development of the Amphibian Embryo The Internal Development of the Amphibian Embryo 21. The Dawn of Analytical Embryology His, Roux, and Mosaic Development Driesch and Regulative Development Novelty in Development Cell Lineage Nucleus or Cytoplasm? Fin de Siècle 22. Interactions during Development Amphibian Organizers Secondary Organizers The Reacting Tissue The Chemical Nature of the Organizer Putting It All Together Conclusion Further Reading References Illustration Credits Index. (shrink)

Abstract: Some seventy years ago, G. E. Moore invoked his own sensory experience (as of a hand before him in the right circumstances), added some philosophical analysis about externality, and took himself to have offered his "Proof" of the existence of an external world. Current neo-Mooreans either reject completely the standard negative assessment of the Proof or qualify it substantially. For Sosa, the Proof can be persuasive, but only when read literally as offering reasons for the conclusion (...) that there is at least one external object—rather than that the prover is justified in believing, or even knowing, that there is at least one external object. Sosa, then, is a neo-Moorean—though not of the sort we might expect in light of the ongoing debate about the Proof. I argue that Sosa needs to say more about the circularity often thought to vitiate the Proof before we can accept his view. (shrink)

It is well known that the probabilistic relation of confirmation is not transitive in that even if E confirms H1 and H1 confirms H2, E may not confirm H2. In this paper we distinguish four senses of confirmation and examine additional conditions under which confirmation in different senses becomes transitive. We conduct this examination both in the general case where H1 confirms H2 and in the special case where H1 also logically entails H2. Based on these analyses, we argue that (...) the Screening-Off Condition is the most important condition for transitivity in confirmation because of its generality and ease of application. We illustrate our point with the example of Moore’s “proof” of the existence of a material world, where H1 logically entails H2, the Screening-Off Condition holds, and confirmation in all four senses turns out to be transitive. (shrink)

The automatic verification of large parts of mathematics has been an aim of many mathematicians from Leibniz to Hilbert. While Gödel's first incompleteness theorem showed that no computer program could automatically prove certain true theorems in mathematics, the advent of electronic computers and sophisticated software means in practice there are many quite effective systems for automated reasoning that can be used for checking mathematical proofs. This book describes the use of a computer program to check the proofs of several celebrated (...) theorems in metamathematics including those of Gödel and Church-Rosser. The computer verification using the Boyer-Moore theorem prover yields precise and rigorous proofs of these difficult theorems. It also demonstrates the range and power of automated proof checking technology. The mechanization of metamathematics itself has important implications for automated reasoning, because metatheorems can be applied as labor-saving devices to simplify proof construction. (shrink)

Moore’s “Proof of an external world” and his “Four forms of scepticism” have long puzzled commentators. How are these adequate responses to sceptics? How, for that matter, is the so-called proof of an external world even pertinent to the challenge of scepticism? The notion of relativized burdens of proof is introduced: this is a burden of proof vis-à-vis one’s opponent that one takes on when trying to convince that someone of something. The relativized burden of (...) proof is a making explicit the truism that if you argue with someone with the intent of trying to convince that someone of something, and if you fail to, you have not met your own conversational goal. Assuming Moore is implicitly relying on the notion of relativized burdens of proof illuminates his approach in these papers. (shrink)

Moore's 'Proof of an External World' has evoked a variety of responses from philosophers, including bafflement, indignation and sympathetic reconstruction. I argue that Moore should be understood as following Thomas Reid on a variety of points, both epistemological and methodological. Moreover, Moore and Reid are exactly right on all of these points. Hence what I present is a defence of Moore's 'Proof', as well as an interpretation. Finally, I argue that the Reid-Moore position is useful for resolving an (...) issue that has recently received attention in epistemology, namely, how is it that one knows that one is not a brain in a vat? (shrink)

Contemporary discussions of skepticism often frame the skeptic's argument around an instance of the closure principle. Roughly, the closure principle states that if a subject knows p, and knows that p entails q, then the subject knows q. The main contention of this paper is that the closure argument for skepticism is defective. We explore several possible classifications of the defect. The closure argument might plausibly be classified as begging the question, as exhibiting transmission failure, or as structurally inefficient. Interestingly, (...) perhaps, each of these has been proposed as the correct classification of Moore's proof of an external world. (shrink)

One of the most important views in the recent discussion of epistemological scepticism is Neo-Mooreanism. It turns a well-known kind of sceptical argument (the dreaming argument and its different versions) on its head by starting with ordinary knowledge claims and concluding that we know that we are not in a sceptical scenario. This paper argues that George Edward Moore was not a Moorean in this sense. Moore replied to other forms of scepticism than those mostly discussed nowadays. His own anti-sceptical (...) position turns out to be very subtle and complex; furthermore it changed over time. This paper follows Moore's views of what the sceptical problem is and how one should respond to it through a series of crucial papers with the main focus being on Moore's 'Proof of an External World'. An appendix deals with the much neglected relation between epistemological scepticism and moral scepticism in Moore. (shrink)

In this paper, I present and criticize a number of influential contemporary anti-skeptical strategies inspired by G.E. Moore’s “proof of an external world”. I argue that these accounts cannot represent a valid response to skeptical worries. Furthermore, drawing on Wittgenstein’s criticisms of Moore, I argue that Radical skeptical hypotheses should be considered nonsensical combinations of signs, excluded from our epistemic practices.

In this paper, I would like to present G.E. Moore’s view on Scepticism and certainty with reference to his papers “Defence of common sense” “Proof of an external world” and “Certainty”. In section I following Moore’s “Proof of an External World” the distinction between empirical objects like paper, human hand, shoes and socks and private objects like images in dreams, double images, after images, and toothache have been highlighted. It has been pointed out that according to (...) Moore, no example of private objects in place of “these are my two hands” could have successfully refuted scepticism; and that Moore does follow Kant’s definition of external objects in order to prove the existence of the external world. The second section emphasizes two points; i) the example of these are my two hands is not a frivolous activity and ii) Moore does recognize the point of Descartes’ dream argument at least to the extent that de does recognize that knowing that P is different from Proving that P. In section III Moore’s attribution of certainty to empirical propositions has been highlighted by responding to the remarks made by Wittgenstein and Malcolm against Moore. In Section IV following Moore’s certainty, a logical explanation of Moore’s thesis that contingent propositions can be certain has been carried out. In addition to that an explanation of how Moore has weakened the dream argument by finding it incoherent. Finally, it has been concluded that Moore’s refutation of scepticism is quite successful in so far as scepticism has no place in common sense. (shrink)

Moore’s essay, “The Refutation of Idealism,” contains a nice illustration of his helping philosophers to see a fact, by removing the obscuring veils that philosophers themselves have spun. Long after he wrote it, Moore called the essay “very confused.” Yet I think that it is one of Moore’s most important papers, a first tentative effort in a series that includes “A Defence of Common Sense” and “Proof of an External World.” I shall not attempt to establish that (...) large claim here. What I want to do is to throw some light on one part of “The Refutation of Idealism.” The distinctive part to be considered follows Moore’s asking the question, “What is a sensation or idea?” on page 17, and runs to near the bottom of page 26. There is much in these pages; but I shall attend only to a certain strand of thought that runs through them: Moore’s analysis of the sensation of blue. (shrink)

Transmission of justification across inference is a valuable and indeed ubiquitous epistemic phenomenon in everyday life and science. It is thanks to the phenomenon of epistemic transmission that inferential reasoning is a means for substantiating predictions of future events and, more generally, for expanding the sphere of our justified beliefs or reinforcing the justification of beliefs that we already entertain. However, transmission of justification is not without exceptions. As a few epistemologists have come to realise, more or less trivial forms (...) of circularity can prevent justification from transmitting from p to q even if one has justification for p and one is aware of the inferential link from p to q. In interesting cases this happens because one can acquire justification for p only if one has independent justification for q. In this case the justification for q cannot depend on the justification for p and the inferential link from p to q, as genuine transmission would require. The phenomenon of transmission failure seems to shed light on philosophical puzzles, such as Moore's proof of a material world and McKinsey's paradox, and it plays a central role in various philosophical debates. For this reason it is being granted continued and increasing attention. (shrink)