Knowledge is analyzed in terms of the cost incurred when mistakes are made — things we should have known better, but didn’t. Following Wittgenstein at the end of On Certainty, an Epistemic Wager, similar to Pascal’s Wager, is set up to represent the cost differences not in belief vs. disbelief, but in knowledge vs. skepticism. This leads to a core class of absolutely certain knowledge, related to Moorean Facts, that is integrated into our everyday lives. This core knowledge is (...) resistant to both radical skepticism, such as a Cartesian Demon, and Gettier style objections, while providing a small, but sufficient base for future epistemological research. (shrink)

During the 1630s Descartes recognized that he could not expect all legitimate claims in natural science to meet the standard of absolute certainty. The realization resulted from a change in his physics, which itself arose not through methodological reflections, but through developments in his substantive metaphysical doctrines. Descartes discovered the metaphysical foundations of his physics in 1629-30; as a consequence, the style of explanation employed in his physical writings changed. His early methodological conceptions, as preserved in the Rules (...) and sketched in Part Two of the Discourse, pertained primarily to his early work in optics. By the early 1630s, Descartes was concerned with new methodological problems pertaining to the postulation of micro-mechanisms. Recognition of the need to employ a method of hypothesis led him to lower the standard of certainty required of particular explanations in his mature physics. (shrink)

The aim of this paper is to vindicate the Cartesian quest for certainty by arguing that to aim at certainty is a constitutive feature of cognition. My argument hinges on three observations concerning the nature of doubt and judgment: first, it is always possible to have a doubt as to whether p in so far as one takes the truth of p to be uncertain; second, in so far as one takes the truth of p to be certain, (...) one is no longer able to genuinely wonder whether p is true; third, to ask the question whether p is to desire to receive a true answer. On this ground I clarify in what sense certainty is the aim of cognition. I then argue that in judging that p we commit ourselves to p’s being certain and that certainty is the constitutive norm of judgment. The paper as a whole provides a picture of the interplay between doubt and judgment that aims at vindicating the traditional insight that our ability to doubt testifies our aspiration to know with absolute certainty. (shrink)

In the philosophical literature on the definition of lying, the analysis is generally restricted to cases of flat-out belief. This chapter considers the complex phenomenon of lies involving partial beliefs – beliefs ranging from mere uncertainty to absolute certainty. The first section analyses lies uttered while holding a graded belief in the falsity of the assertion, and presents a revised insincerity condition, requiring that the liar believes the assertion to be more likely to be false than true. The (...) second section analyses assertions that express graded beliefs, exploring how mitigation and reinforcement can alter the insincerity conditions for lying. The last section considers the case of lies that attack certainty (knowledge-lies), understood as attempt to alter the hearer's graded beliefs. (shrink)

Hume appeals to different kinds of certainties and necessities in the Treatise. He contrasts the certainty that arises from intuition and demonstrative reasoning with the certainty that arises from causal reasoning. He denies that the causal maxim is absolutely or metaphysically necessary, but he nonetheless takes the causal maxim and ‘proofs’ to be necessary. The focus of this paper is the certainty and necessity involved in Hume’s concept of knowledge. I defend the view that intuitive certainty, (...) in particular, is certainty of the invariability or necessity of relations between ideas. Against David Owen and Helen Beebee, I argue that the certainty involved in intuition depends on the activity of the mind. I argue, further, that understanding this activity helps us understand more clearly one of Hume’s most important theses, namely that experience is the source of a distinct kind of certainty and of necessity. (shrink)

Demands for absolute or near certainty are a common way for those with a political agenda to undermine science and to delay action. Through our combined experience in science, philosophy and cultural theory, we are acquainted with these attempts to undermine science. We want to help readers figure out how to evaluate their merits or lack thereof.

This paper presents a critical review and discussion of three recent major theories of epistemic scepticism. Odegard and Rescher both agree that real knowledge entails certain beliefs. But they both fail to see how beliefs could be absolutely certain. Klein’s book, Certainty: A Refutationof Scepticism, presents the strongest possible view in favor of absolute certainty. I pay attention to its technical details and development by Klein. My conclusion is that Klein’s theory rests on some presupposed ideas that (...) are either counterintuitive or then make the theory trivial: one’s certainty of truth becomes the same as the truth itself. (shrink)

This paper presents a critical review and discussion of three recent major theories of epistemic scepticism. Odegard and Rescher both agree that real knowledge entails certain beliefs. But they both fail to see how beliefs could be absolutely certain. Klein’s book, Certainty: A Refutationof Scepticism, presents the strongest possible view in favor of absolute certainty. I pay attention to its technical details and development by Klein. My conclusion is that Klein’s theory rests on some presupposed ideas that (...) are either counterintuitive or then make the theory trivial: one’s certainty of truth becomes the same as the truth itself. (shrink)

This paper presents the concept of ‘religious certainty’ I have developed by drawing inspiration from Wittgenstein’s notion of ‘certainty’. After describing the particular traits of religious certainty, this paper addresses two difficulties derived from this concept. On the one hand, it explains why religious certainty functions as such even though all its consequences are far from being absolutely clear; on the other hand, it clarifies why, unlike the rest of certainties, the loss of religious certainty (...) does not result in the collapse of the world-picture made up of all certainties. Subsequently, it analyzes to what extent the teacher can teach religious certainty by acting as a facilitator for its acquisition–if desired—particularly bearing in mind that religious certainty cannot be attained at will. These basic teaching guidelines have several advantages. First, they make it possible to know the nature of religious certainty even better. Second, and most importantly, the fact of having adopted the perspective of a teacher who tries inculcating a religious certainty contributes to detecting and preventing forms of indoctrination that, arguably, might go unnoticed even when attempting to properly present religious certainty—or rather, this way of being religious—in current schools to foster understanding thereof. (shrink)

Probability can be used to measure degree of belief in two ways: objectively and subjectively. The objective measure is a measure of the rational degree of belief in a proposition given a set of evidential propositions. The subjective measure is the measure of a particular subject’s dispositions to decide between options. In both measures, certainty is a degree of belief 1. I will show, however, that there can be cases where one belief is stronger than another yet both beliefs (...) are plausibly measurable as objectively and subjectively certain. In ordinary language, we can say that while both beliefs are certain, one belief is more certain than the other. I will then propose second, non probabilistic dimension of measurement, which tracks this variation in certainty in such cases where the probability is 1. A general principle of rationality is that one’s subjective degree of belief should match the rational degree of belief given the evidence available. In this paper I hope to show that it is also a rational principle that the maximum stake size at which one should remain certain should match the rational weight of certainty given the evidence available. Neither objective nor subjective measures of certainty conform to the axioms of probability, but instead are measured in utility. This has the consequence that, although it is often rational to be certain to some degree, there is no such thing as absolute certainty. (shrink)

Philosophers frequently treat certainty as some sort of absolute, while ordinary men typically do not. According to the Theory of Important Criteria, on which the present paper is based, this difference is not to be explained in terms of ambiguity or vagueness in the word?certain?, but rather in terms of disagreement between ordinary men and philosophers as to the importance of one of the criteria of the ordinary sense of?certain?. I argue that there is reason to think that (...) certainty is some sort of absolute, and thus that no empirical statement is certain. And in any case, the problem of empirical certainty is not a pseudo?problem, as metaphilosophers like Wittgenstein and Wisdom have thought. (shrink)

In the Principles of Philosophy, Descartes explains several observable phenomena showing that they are caused by special arrangements of unobservable microparticles. Despite these microparticles being unobservable, many passages suggest that he was very confident that these explanations were correct. In other passages, however, Descartes points out that these explanations merely hold the status of “suppositions” or “conjectures” that could be wrong. My main goal in this chapter is to clarify this apparent conflict. I argue first that for Descartes it was (...) indeed possible to have knowledge of unobservable particles and structures, and that the possibility of natural explanations being wrong should be understood as these explanations not being absolutely certain, but only morally certain. I use the debate in contemporary philosophy of science between scientific realism and antirealism as a framework to understand how Cartesian explanations work. Especifically, I argue that Cartesian explanations rely on what Ernan McMullin calls retroduction, which is a mode of inference that justifies beliefs in concrete unobservable entities and processes, based on considerations such as simplicity, coherence, etc. This kind of justification is of common use among scientific realists. Thus, another goal of this chapter is to highlight the relevance of Descartes’ ideas about explanation in the contemporary debate on scientific realism. (shrink)

Assertions have a curious relationship to certainty. On the one hand, it seems clear that we can assert many everyday propositions while not being absolutely certain about them. On the other hand, it seems odd to say things like ‘p, but I am not absolutely certain that p’. In this paper, I aim to solve this conundrum. I suggest a pretense theory of assertion, according to which assertions of p are proposals to act as if the conversational participants were (...) absolutely certain of p. I suggest that this explains why absolute certainty is not required to make assertions, while it is still problematic to voice your uncertainties once you have made an assertion. By voicing your uncertainties, you thwart your very own proposal to act as if everybody was absolutely certain. (shrink)

The absolute self-evidence of consciousness is due to the fact that the object of consciousness is present or immanent in it. We may therefore formulate the absolutely certain starting point of philosophy as follows: knowledge about an object immanent in consciousness is absolutely certain in so far as it is the actual testimony of the object about itself, and does not go beyond that which is present in consciousness. The criterion of the absolute certainty of such knowledge (...) is self evidence, i.e. the fact that it consists entirely of what is present in consciousness. To doubt such knowledge is absurd because it is not a copy of the object, it is not a symbol of it, but simply and directly contains the object itself as known. I designate the act of the immediate contemplation of objects by the term intuition. According to the epistemological theory which I began to work out in 1903 all our trustworthy knowledge is obtained by means of such immediate observation of objects as they are in themselves; I therefore call my theory of knowledge Intuitivism. (shrink)

The University of Michigan conference “Where Religion, Policy, and Bioethics Meet: An Interdisciplinary Conference on Islamic Bioethics and End-of-Life Care” in April 2011 addressed the issue of brain death as the prototype for a discourse that would reflect the emergence of Islamic bioethics as a formal field of study. In considering the issue of brain death, various Muslim legal experts have raised concerns over the lack of certainty in the scientific criteria as applied to the definition and diagnosis of (...) brain death by the medical community. In contrast, the medical community at large has not required absolute certainty in its process, but has sought to eliminate doubt through cumulative diagnostic modalities and supportive scientific evidence. This has recently become a principal model, with increased interest in data analysis and evidence-based medicine with the intent to analyze and ultimately improve outcomes. Islamic law has also long employed a systematic methodology with the goal of eliminating doubt from rulings regarding the question of certainty. While ample criticism of the scientific criteria of brain death (Harvard criteria) by traditional legal sources now exists, an analysis of the legal process in assessing brain death, geared toward informing the clinician’s perspective on the issue, is lacking. In this article, we explore the role of certainty in the diagnostic modalities used to establish diagnoses of brain death in current medical practice. We further examine the Islamic jurisprudential approach vis-à-vis the concept of certainty (yaqīn). Finally, we contrast the two at times divergent philosophies and consider what each perspective may contribute to the global discourse on brain death, understanding that the interdependence that exists between the theological, juridical, ethical, and medical/scientific fields necessitates an open discussion and active collaboration between all parties. We hope that this article serves to continue the discourse that was successfully begun by this initial interdisciplinary endeavor at the University of Michigan. (shrink)

Bacon’s project suggests in theory that the obtaining of absolute certain knowledge is possible but in fact such knowledge is revealed to be impossible. Th e description of the human mind on which Bacon’s account is based seems to imply that the impossibility of obtaining absolute certainty does not depend on the contingent historical situation of a preliminary stage of the scientifi c endeavor. Consequently, a gap emerges between the proposed goal of science and the ways to (...) reach it: Bacon tried to obtain absolute certainty but he only could arrive at degrees of certainty and probability both in theories and in facts. Malgrè lui, Bacon shows himself developing in fact a kind of probabilistic science instead of surpassing the limits to knowledge posed by the skeptical arguments. Th at is the reason why many of his followers could develop a mitigated skepticism in the framework of a Baconian science. (shrink)

The Thomistic doctrine of adequatio seems to endure as a current topic in contemporary debates on the accessibility of truth in trials, since it can account for the objectivity of our knowledge, while avoiding anti-correspondence objections. It can, thus, offer an important contribution to forensic epistemology, in particular in force of the fact that, in conjunction with Thomistic reflections on the certitudo probabilis of witnesses, it allows us to combine the claim that, in legal matters (like in all variable and (...) contingent subjects), we can never reach absolute certainty, with the conviction that one can nonetheless know what, with more probability, really happened. (shrink)

Marcus Giaquinto traces the story of the search for firm foundations for mathematics. The nineteenth century saw a movement to make higher mathematics rigorous; this seemed to be on the brink of success when it was thrown into confusion by the discovery of the class paradoxes. That initiated a period of intense research into the foundations of mathematics, and with it the birth of mathematical logic and a new, sharper debate in the philosophy of mathematics. The Search for Certainty (...) focuses mainly on two major twentieth-century programmes: Russell's logicism and Hilbert's finitism. Giaquinto examines their philosophical underpinnings and their outcomes, asking how successful they were, and how successful they could be, in placing mathematics on a sound footing. He sets these questions in the context of a clear, non-technical exposition and assessment of the most important discoveries in mathematical logic, above all Gödel's underivability theorems.More than six decades after those discoveries Giaquinto asks what our present perspective should be on the question of certainty in mathematics. Taking recent developments into account, he gives reasons for a surprisingly positive response. (shrink)

Ordinary skepticism is based upon some form of certainty. One may be skeptical about the claims of religion because one accepts the certainties of science or some philosophical argument. One may be skeptical about a certain investment strategy because one believes in various proven economic principles. Absoluteskepticism, on the other hand, has no such certainty upon which to rely. Every standpoint, including absolute skepticism itself, is open to doubt. Thus absolute skepticism is not another philosophical position (...) but raises severe doubt about all philosophy and all knowledge. In this paper I will explore some of the implications of absolute skepticism and how Lao Zi and Jiddu Krishnamurti (1895-1986) may serve as possible representatives of absolute skepticism. (shrink)

Peter Klein claims to have explicated the notion of relative certainty and shown how it is related to the notion of absolute evidential certainty in his book Certainty. I argue that he has not succeeded at this because the account of relative certainty provided only applies to a subset of the pairs of propositions about which we make judgments of relative certainty.

Peter Klein claims to have explicated the notion of relative certainty and shown how it is related to the notion of absolute evidential certainty in his book Certainty. I argue that he has not succeeded at this because the account of relative certainty provided only applies to a subset of the pairs of propositions about which we make judgments of relative certainty.

Current dogma holds that all cultures and moral values are conditional, nothing human is innate, and Einstein proved that the whole universe is "relative." Challenging this position, William Gairdner argues that relativism is not only logically and morally self-defeating but that progress in scientific and intellectual disciplines has actually strengthened the case for absolutes, universals, and constants of nature and human nature. Gairdner refutes the popular belief in cultural relativism by showing that there are hundreds of well-established cross-cultural "human universals." (...) He then discusses the many universals found in physics - as well as Einstein's personal regret at how his work was misinterpreted by the public's eagerness to promote relativism. Gairdner also gives a lively account of the many universals of human biology, including the controversial topic of universal gender differences or "brain sex." He then looks at universal concepts of both natural and international law, and ends by discussing language theory. He shows how philosophers from Nietzsche to Derrida have misused linguistic concepts to justify their relativism, even though a sustained and successful effort by serious scientists and philosophers of language has revealed myriad universals of human language, ranging from language acquisition, to word-order, to "Universal Grammar." From ethics to Einstein, culture to biology, law to language, The Book of Absolutes makes complex topics accessible to a broad audience and demonstrates that there are plenty of certainties, even in our postmodern world. (shrink)

"Certainty" occupies an important place in Wittgenstein’s epistemology: it does not belong to the category of knowledge but constitutes its foundation. In his view, knowledge boils down to language games, and language games are based on indubitable certainties. According to Wittgenstein, scepticism is meaningless, and if there is no certainty, then even doubt would be meaningless. Wittgesntein maintains that [relative] doubt and knowledge are epistemic categories, whereas absolute doubt and certainty are non-epistemic categories. Epistemic categories are (...) meaningful and when expressed by means of statements could be either true or false. In contrast, non-epistemic categories are meaningless and when expressed by means of statements the properties of truth and falsehood do not apply to them. The aim of the present paper is two fold: 1- Providing an explanation of the status of certainty in comparison to categories such as doubt and knowledge in Wittgenstein’s thought; 2- Providing a critical assessment of Wittgenstein's approach to certainty through the prism of critical rationalism. The main arguments of the paper are as follows: 1. Although Wittgenstein considers certainty to be meaningless and therefore not on a par with epistemological categories, he regards it as an objective concept that functions as the foundation upon which all human knowledge is based; 2. Wittgenstein's efforts to show the objectivity of certainty have not been entirely successful, partly due to his reliance on a defective notion of ‘objectivity’ and partly as a result of the prominence he assigns to the category of ‘meaning’ at the expense of the category of ‘truth’. (shrink)

According to Flay, the theme of Hegel's Phenomenology is a quest for warranted certainty of access to reality, a quest separate from, and yet essential to, the science which will "articulate the ultimate truth about ultimate reality". Such a quest requires a presuppositionless beginning, one that cannot be questioned by either the philosophical tradition or consciousness in its natural attitude. Flay proposes that Hegel achieves such a beginning, first, by not assuming absolute access to reality as an answer (...) already given, but as a problem inherited from the philosophical tradition. Flay maintains that the natural attitude has a natural certainty of access to reality. Hegel's second requirement for a presuppositionless beginning, then, consists in critically accepting the natural attitude's certainty. The quest for certainty will simply involve determining the self-warranting grounds for this certainty. (shrink)

A lively challenge to postmodern opinion that reveals satisfying and reliable certainties.

In lieu of an abstract, here is a brief excerpt of the content:Journal of the History of Ideas 61.1 (2000) 97-114 [Access article in PDF] Blackloism and Tradition: From Theological Certainty to Historiographical Doubt Beverley C. Southgate * Introduction "Pyrrho himself never advanced any Principle of Scepticism beyond this," complained John Tillotson at the height of the seventeenth-century "rule of faith" debates; 1 and John Sergeant, as Catholic champion and the object of his charge, must have noted the irony. (...) For Tillotson was not unreasonable in concluding that his adversary's theological arguments had the effect of increasing the very uncertainty which they were designed to combat. Sergeant's attempts to overcome scepticism in theology were actually destined to exacerbate the problem of scepticism in relation to historiography.John Sergeant (1623-1707) was an English secular priest and, more specifically, a member of that notorious faction of Catholics known as "Blackloists," followers of Thomas White (1593-1676), alias Blacklo. 2 White produced some forty works on theology, natural philosophy, and political theory; he was known as an eminent philosopher in his own day and has more recently been restored to wider interest following the publication of Hobbes's lengthy critique of his cosmological treatise De Mundo. Sergeant has remained best known for his advocacy of the Catholic position in the "rule of faith" debates, but he was also a prolific writer on philosophy and, as a late Aristotelian, took issue with such "modernists" as Descartes and Locke. 3 Sergeant was widely recognized as White's [End Page 97] intellectual disciple, and it will be convenient here to consider their thought together. 4 Both devoted much of their time and energy (in Sergeant's words) to "beating down scepticism" or, as White had earlier called it, the "contagion of Pyrrhonism"; and both would have been horrified to think that they had actually contributed to any extension of skeptical philosophy. 5Blackloist concerns with the refutation of skeptically induced uncertainty had obvious implications for their contributions to the "rule of faith" debates and to their attempted establishment of one single and certain ground of religious belief. During the latter half of the seventeenth century Protestants and Catholics expended a considerable amount of intellectual and emotional energy in advocating their respective routes to that level of religious certainty which would assure salvation. While the former expressed confidence in the reliability of the scriptures' literary record, the latter counter-claimed that they alone enjoyed a faith that was reliably grounded in an unbroken tradition deriving from Christ himself.Thomas White highlights these issues in his additions to the "corrected and enlarged" 1654 edition of William Rushworth's Dialogues, in which he laments the fragmenting effects of the Reformation. White argues that because they no longer enjoy "one rule among them all" Protestants resort to their various individual principles; and although all appeal ultimately to the authority of the Bible, they each have only their own "private conceit" by which to resolve any ambiguities in the scriptural record. The extraction of religious tenets then becomes effectively a matter of mere guesswork; the whole Bible might as well be replaced by the Koran. Something far more authoritative, White insists, is needed to overcome theological uncertainty--"this dangerous Cockatrice, Incertitude"; 6 and it is precisely such firmly based and wholly reliable authority that he and Sergeant strove to provide. [End Page 98]In this context, however, theology became intimately interrelated with historiography. Some of the difficulties attendant on the Protestant recourse to the Bible were no doubt specific to the Bible itself, but others related more generally to the validity of any historical record, and it is some of the wider historiographical implications of theological debate that I shall examine in this paper. By arguing against the skeptics and pragmatic Protestants while simultaneously insisting on their own variety of absolute theological certainty based on reliable historical tradition, the Blackloists actually contributed to the development of that form of historiographical uncertainty which culminated in what, by the end of the century, came to be known as "Historical Pyrrhonism." 7 The Scriptures: Linguistic and Literary Problems "For since the... (shrink)

The article proposes a phenomenological journey through three concepts of uncertainty – those of Blaise Pascal, Ludwig Wittgenstein, and Jan Patočka. The discussion focuses on the meaning of certainty and uncertainty and on the mutual relations between the two according to each philosopher. Adopting an embodied philosophical-poetic perspective enables the dialectical relations prevailing between these three conceptions to emerge, clarifying that, despite their differences, they share a deep attachment to the transcendent dimension of human existence. This dimension is described (...) as “uncertain certainty,” implying attention to the quiver of absolute meaning dwelling within and beyond the movement of humans and the lifeworld. (shrink)

This article examines the emphasis on facts and data in public discourse, and the belief that they provide a certainty necessary for public judgment and collective action. The heart of this belief is what I call the “myth of the Absolute,” which is the belief that by basing our judgment and actions on an Absolute we can avoid errors and mistakes. Myths of the Absolute can help us deal with wicked problems such as climate change, but (...) they also have a downside. This article explores the experience behind these myths, to better understand how they describe and mediate our experiences of uncertainty, then relates these myths to debates about climate change. I conclude by describing how to engage these myths in a way that promotes better public discourse—and thus better public judgment and collective action—by telling these stories in such a way that we poke and prod wherever the story is not. (shrink)

Why absolute certainty is impossible in science In today's unpredictable and chaotic world, we look to science to provide certainty and answers—and often blame it when things go wrong. The Blind Spot reveals why our faith in scientific certainty is a dangerous illusion, and how only by embracing science's inherent ambiguities and paradoxes can we truly appreciate its beauty and harness its potential. Crackling with insights into our most perplexing contemporary dilemmas, from climate change to the (...) global financial meltdown, this book challenges our most sacredly held beliefs about science, technology, and progress. At the same time, it shows how the secret to better science can be found where we least expect it—in the uncertain, the ambiguous, and the inevitably unpredictable. William Byers explains why the subjective element in scientific inquiry is in fact what makes it so dynamic, and deftly balances the need for certainty and rigor in science with the equally important need for creativity, freedom, and downright wonder. Drawing on an array of fascinating examples—from Wall Street's overreliance on algorithms to provide certainty in uncertain markets, to undecidable problems in mathematics and computer science, to Georg Cantor's paradoxical but true assertion about infinity—Byers demonstrates how we can and must learn from the existence of blind spots in our scientific and mathematical understanding. The Blind Spot offers an entirely new way of thinking about science, one that highlights its strengths and limitations, its unrealized promise, and, above all, its unavoidable ambiguity. It also points to a more sophisticated approach to the most intractable problems of our time. (shrink)

Why engage in inquiry? According to many philosophers, the goal of inquiring into some question is to come to know its answer. While this view holds considerable appeal, this paper argues that it stands in tension with another highly attractive thesis: knowledge does not require absolute certainty. Forced to choose between these two theses, I argue that we should reject the idea that inquiry aims at knowledge. I go on to develop an alternative view, according to which inquiry (...) aims at maximizing the epistemic value of our credences. This alternative view makes room for knowledge that falls shy of certainty, and it coheres nicely with a rich body of work in epistemic decision theory. I proceed to highlight the implications of this replacement for some important topics in epistemology, including the dogmatism paradox, the nature of interrogative attitudes, and the norm of practical reasoning. (shrink)

Did G. E. Moore prove the existence of things outside us? Philosophers have objected to his proof, but not for good reasons. Since when, for instance, has absolute certainty been the mark of philosophy? But Moore's proof was superfluous, as its conclusion had already been proved previously.

Recent Cartesian scholarship postulates two Descartes, separating Descartes into a scientist and a metaphysician. The purpose varies, but one has been to show that the metaphysical Descartes, of the Meditations, is less genuine than the scientific Descartes. Accordingly, discussion of God and the soul, the evil demon, and the non-deceiving God were elements of rhetorical strategy to please theologians, not of serious philosophical argumentation. I agree in finding two Descartes, but the two I identify are not scientist and philosopher, but (...) practitioner and methodologist of the mathematical sciences on the one hand, and metaphysician of a new, general science of nature on the other. This chapter examines the transition to the second Descartes, and especially the metaphysical turn. It proposes that although Descartes' doubt was methodological and he felt no serious threat from skepticism and absolute certainty was not his primary goal. Rather, the doubt was used to reform the intellect, or to teach the use of the pure intellect (and to obtain certainty in that domain). Further, Descartes' metaphysics was primarily in the service of his natural philosophy (where in the main he did not claim absolute certainty). He did not talk about God and the soul in order to fool the theologians. His discussion of the relation between God and human reason was part of a metaphysical strategy in which, through his doctrine on the eternal truths, he separated knowledge of the first principles of natural philosophy (gained by the natural light) from theological cognition (through the light of grace), thereby seeking to render his metaphysics distinct from the proper domain of theology. (shrink)

Unger (1974/2000) presents an argument for skepticism that significantly differs from the more traditional arguments for skepticism. The argument is based on two premises, to wit, that knowledge would entitle the knower to absolute certainty, and that an attitude of absolute certainty is always inadmissible from an epistemic viewpoint. The present paper scrutinizes the arguments that Unger provides in support of these premises and shows that none of them is tenable. It thus concludes that Unger's argument (...) for skepticism fails to threaten the possibility of knowledge. (shrink)