I will discuss a variety of cases such that the subject's believing truly is somewhat of an accident, but less so than in a Gettier case. In each case, this is because her reasons are not ultimately undefeated full stop, but they are ultimately undefeated with certain qualifications. For example, the subject's reasons might be ultimately defeated considered in themselves but ultimately undefeated considered as a proper part of an inference to the best explanation that is undefeated without qualification. In (...) each section of the paper, I consider different qualifications and show how in each case we get an epistemic standing I call “coach-class knowledge”. First-class knowledge requires justifying reasons that are undefeated without qualification. Coach-class knowledge only requires qualified lack of defeat. I will use this distinction to bring debates over knowledge from falsehood and fake barns to an ecumenical resolution. In both cases, the subject enjoys coach-class rather than first-class knowledge. I will also show that the defeasible reasoning tradition can better account for graded accidental truth than safety theories. (shrink)

Mark Schroeder’s Reasons First is admirable in its scope and execution, deftly demonstrating the theoretical promise of extending the reasons-first approach from ethics to epistemology. In what follows we explore how (not) to account for the evidence-that relation within the reasons-first program, we explain how factive content views of evidence can be resilient in the face of Schroeder’s criticisms, and we explain how knowledge from falsehood threatens Schroeder’s view of knowledge. Along the way we sketch a reliabilist account of the (...) reasons-for relation (inspired by Alston) and show how it limits the applicability of Schroeder’s arguments. (shrink)

According to the safety account of knowledge, one knows that p only if one’s belief could not easily have been false. An important issue for the account is whether we should only examine the target belief when evaluating whether a belief is safe or not. In this paper, it is argued that, if we should only examine the target belief, then the account fails to account for ignorance of necessary truths. But, if we should also examine beliefs in other relevant (...) propositions, then the account fails to account for knowledge from falsehood. Therefore, the safety account of knowledge is undermined by knowledge from falsehood and ignorance of necessary truths. (shrink)

This paper examines two objections to the infinitist theory of epistemic justification, namely “the finite mind objection” and “the distinction objection.” It criticizes Peter Klein’s response to the distinction objection and offers a more plausible response. It is then argued that this response is incompatible with Klein’s response to the finite mind objection. Infinitists, it would seem, cannot handle both objections when taken together.

In some recent work, John N.Williams defends a new objection to the defeasibility theory of knowledge. But the objection is of wider interest, since Williams also suggests that this style of objection may undermine other theories of knowledge. I distinguish two versions of Williams’ objection. I then show that the first version relies on false conceptual principles, and the second relies on a specific and dubious conception of the goal of the analysis of knowledge.

A number of philosophers have recently proposed several alleged cases of “knowledge from falsehood,” i.e., cases of inferential knowledge epistemised by an inference with a false crucial premise. This paper examines such cases and argues against interpreting them as cases of knowledge from falsehood. Specifically, I argue that the inferences in play in such cases are in no position to epistemise their conclusions.

There are many important dimensions of epistemic evaluation, one of which is justification. We don’t just evaluate beliefs for truth, reliability, accuracy, and knowledge, but also for justification. However, in the epistemological literature, there is much disagreement about the nature of justification and how it should be understood. One of the controversies that has separated the contemporary epistemological discourse into two opposing camps has to do with the internalism-externalism distinction. Whereas internalists defend certain core assumptions about justification from the pre-Gettier (...) tradition, externalists generally think that the traditional conception is untenable and should be replaced. In this compilation thesis, I argue for, defend, and develop a particular brand of internalism, both in general and with respect to specific sources of justification. In papers 1 and 2, I defend a couple of well-known arguments for mentalism and accessibilism. Moreover, I also point out how prominent versions of these theses are vulnerable to serious problems (e.g., about over-intellectualization and vicious regresses). Part of my goal in the first couple of papers is to figure out what commitments the internalist should take on in order to avoid the externalist's objections, while at the same time receiving support from considerations that have motivated internalism in the past. In papers 3 and 4, I start from the assumption that mentalism is true and attempt to answer the following questions: 1) which non-factive mental states can play a justification-conferring role with respect to empirical belief? And 2) why does this set of states play the epistemic role it does? In response to question 1, I argue that all and only one's beliefs and perceptual experiences have justificatory relevance. In response to question 2, I argue that one's beliefs and perceptual experiences are one's strongly representational states, and that strongly representational states necessarily provide support to certain empirical propositions. Having done so, I then defend mentalism about scientific evidence from a couple of prominent objections in the recent literature. Lastly, in papers 5 and 6, I argue for a particular brand of internalism about testimonial and memorial justification and show how that position has a dialectical advantage over its main competitors. (shrink)

Philosophers have debated whether it is possible to knowledgeably infer a conclusion from a false premise. For example, if a fan believes that the actress’s dress is blue, but the dress is actually green, can the fan knowledgeably infer “the dress is not red” from “the dress is blue”? One aspect of this debate concerns what the intuitively correct verdict is about specific cases such as this. Here I report a simple behavioral experiment that helps answer this question. The main (...) finding is that people attribute knowledge in cases where a true conclusion is inferred from a false premise. People did this despite judging that the premise was false and unknown. People also viewed the agent as inferring the conclusion from the premise. In closely matched conditions where the conclusion was false, people did not attribute knowledge of the conclusion. These results support the view that the ordinary knowledge concept includes in its extension cases of knowledge inferred from false premises. (shrink)

Facts about justification are not brute facts. They are epistemic facts that depend upon more fundamental non-epistemic facts. Internalists about justification often argue for mentalism, which claims that facts about justification supervene upon one’s non-factive mental states, using Lehrer and Cohen’s :191–207, 1983) New Evil Demon Problem. The New Evil Demon Problem tells you to imagine yourself the victim of a Cartesian demon who deceives you about what the external world is like, and then asks whether you nevertheless have justification (...) for your beliefs about the external world. Internalists and externalists agree that there is something that is epistemically good or valuable about both your actual beliefs and your beliefs in the demon scenario. Internalists claim that the epistemic property which these sets of beliefs share most intuitively should be thought of as sameness of justification. Externalists, on the other hand, reject this claim, usually either by challenging the internalist intuition directly, or by arguing that there is a more plausible way to think about the epistemic property in question. Recently, both kinds of externalist objection have been raised against the argument from the New Evil Demon Problem for mentalism. The goal of this paper is to defend the argument against three prominent objections—a pair of which is offered by Littlejohn :399–434, 2009) and one by Williamson Rationality and the good: critical essays on the ethics and epistemology of Robert Audi, Oxford University Press, Oxford, 2007; in: Dutant J, Dohrn D The new evil demon, Oxford University Press, Oxford, 2016). (shrink)

Epistemic luck is a generic notion used to describe any of a number of ways in which it can be accidental, coincidental, or fortuitous that a person has a true belief. For example, one can form a true belief as a result of a lucky guess, as when one believes through guesswork that “C” is the right answer to a multiple-choice question and one’s belief just happens to be correct. One can form a true belief via wishful thinking; for example, (...) an optimist’s belief that it will not rain may luckily turn out to be correct, despite forecasts for heavy rain all day. One can reason from false premises to a belief that coincidentally happens to be true. One can accidentally arrive at a true belief through invalid or fallacious reasoning. And one can fortuitously arrive at a true belief from testimony that was intended to mislead but unwittingly reported the truth. In all of these cases, it is just a matter of luck that the person has a true belief. -/- Until the twenty-first century, there was nearly universal agreement among epistemologists that epistemic luck is incompatible with knowledge. Call this view “the incompatibility thesis.” In light of the incompatibility thesis, epistemic luck presents epistemologists with three distinct but related challenges. The first is that of providing an accurate analysis of knowledge (in terms of individually necessary and jointly sufficient conditions for “S knows that p,” where ‘S’ represents the knower and ‘p’ represents the proposition known). An adequate analysis of knowledge must succeed in specifying conditions that rule out all instances of knowledge-destroying epistemic luck. The second challenge is to resolve the skeptical paradox that the ubiquity of epistemic luck generates: As will become clear in section 2c, epistemic luck is an all-pervasive phenomenon. Coupling this fact with the incompatibility thesis entails that we have no propositional knowledge. The non-skeptical epistemologist must somehow reconcile the strong intuition that epistemic luck is not compatible with knowledge with the equally evident observation that it must be. The third challenge concerns the special skeptical threat that epistemic luck seems to pose for more reflective forms of knowledge, such as knowing that one knows. Each of these challenges will be explored in the present article. (shrink)

Can understanding be based on false beliefs? I argue that it can. I first argue that the best way to understand the question is that it is whether one can increase one's degree of understanding by adopting an overall less accurate body of beliefs. I identify three sufficient conditions for one body of beliefs to be more accurate than another. Next, I appeal to two widely used methods of comparing degrees of understanding. With these methods, I show that understanding can (...) be gained by acquiring false beliefs. In addition, I show that this implies that understanding is not factive. (shrink)

Under what conditions is a belief inferentially justified? A partial answer is found in Justification from Justification : a belief is inferentially justified only if all of the beliefs from which it is essentially inferred are justified. After reviewing some important features of JFJ, I offer a counterexample to it. Then I outline a positive suggestion for how to think about inferentially justified beliefs while still retaining a basing condition. I end by concluding that epistemologists need a model of inferentially (...) justified belief that is more permissive and more complex than JFJ. (shrink)

In a Normal Case, a subject has a justified true belief that P and also knows that P. In a Gettier Case, a subject has a justified true belief that P but does not know that P. The received view (endorsed by Lycan and others) is that if one is in a Normal Case then one cannot know that he is not in a Gettier case. I argue that the received view is mistaken and I discuss the implications this has (...) on some other epistemological issues. (shrink)

If evidence is propositional, is one’s evidence limited to true propositions or might false propositions constitute evidence? In this paper, I consider three recent attempts to show that there can be ‘false evidence,’ and argue that each of these attempts fails. The evidence for the thesis that evidence consists of truths is much stronger than the evidence offered in support of the theoretical assumptions that people have relied on to argue against this thesis. While I shall not defend the view (...) that evidence is propositional, I shall defend the view that any propositional evidence must be true. (shrink)

Current epistemological orthodoxy has it that knowledge is incompatible with luck. More precisely: Knowledge is incompatible with epistemic luck . This is often treated as a truism which is not even in need of argumentative support. In this paper, I argue that there is lucky knowledge. In the first part, I use an intuitive and not very developed notion of luck to show that there are cases of knowledge which are “lucky” in that sense. In the second part, I look (...) at philosophical conceptions of luck and come to the conclusion that knowledge can be lucky in those senses, too. I also turns out that a probabilistic notion of luck can help us see in what ways a particular piece of knowledge or belief can be lucky or not lucky. (shrink)

Probabilistic support is not transitive. There are cases in which x probabilistically supports y , i.e., Pr( y | x ) > Pr( y ), y , in turn, probabilistically supports z , and yet it is not the case that x probabilistically supports z . Tomoji Shogenji, though, establishes a condition for transitivity in probabilistic support, that is, a condition such that, for any x , y , and z , if Pr( y | x ) > Pr( y (...) ), Pr( z | y ) > Pr( z ), and the condition in question is satisfied, then Pr( z | x ) > Pr( z ). I argue for a second and weaker condition for transitivity in probabilistic support. This condition, or the principle involving it, makes it easier (than does the condition Shogenji provides) to establish claims of probabilistic support, and has the potential to play an important role in at least some areas of philosophy. (shrink)

The safety conception of knowledge holds that a belief constitutes knowledge iff relevantly similar beliefs—its epistemic counterparts—are true. It promises an instructive account of why certain general principles of knowledge hold. We focus on two such principles that anyone should endorse: the closure principle that knowledge is downward closed under competent conjunction elimination, and the counter-closure principle that knowledge is upward closed under competent conjunction introduction. We argue that anyone endorsing the former must also endorse the latter on pains of (...) an unacceptable form of bootstrapping. We devise new formal models to identify necessary and sufficient conditions for these principles to hold on conceptions that construe knowledge in terms of true counterparts. These conditions state that counterparts of premise and conclusion beliefs are coordinated in certain ways whenever these beliefs stand in the relevant inferential relations. We show that the safety conception faces insuperable problems vindicating these coordination principles, because its epistemic counterpart relation is symmetric. We conclude that it thus proves unable to account for minimal closure properties of knowledge. More generally, our formal results establish parameters within which any conception must operate that construes knowledge in terms of true counterparts. (shrink)

The paper introduces a new problem for fallibilist and infallibilist epistemologies – the diachronic threshold problem. As the name suggests, this is a problem similar to the well–known threshold problem for fallibilism. The new problem affects both fallibilism and infallibilism, however. The paper argues that anyone who worries about the well known problem for fallibilism should also worry about this new, diachronic version of the problem.

An explanation is given of why it is in the nature of inquiry into whether or not p that its aim is fully achieved only if one comes to know that p or to know that not-p and, further, comes to know how one knows, either way. In the absence of the latter one is in no position to take the inquiry to be successfully completed or to vouch for the truth of the matter in hand. An upshot is that (...) although knowledge matters because truth matters this should not be understood to mean that knowledge matters because true belief matters. (shrink)

I examine the claim, made by some authors, that we sometimes acquire knowledge from falsehood. I focus on two representative cases in which a subject S infers a proposition q from a false proposition p. If S knows that q, I argue, S's false belief that p is not essential to S's cognition. S's knowledge is instead due to S's belief that p′, a proposition in the neighbourhood of p that S believes . S thus knows despite her false belief. (...) The widely accepted and plausible principle that inferential knowledge requires known premises is unscathed. (shrink)

This paper argues that for someone to know proposition p inferentially it is not enough that his belief in p and his justification for believing p covary with the truth of p through a sphere of possibilities. A further condition on inferential knowledge is that p's truth-maker is identical with, or causally related to, the state of affairs the justification is grounded in. This position is dubbed ‘identificationism.’.

Deviant causal chain problems arise in many settings. The most famous instance of the problem is the Gettier problem, but the problem also arises in the philosophy of action and perception. Usually, attempts to tackle these problems try to solve them individually. This paper takes a different approach: I propose a general solution to the problem. I begin by providing a solution to the deviant causal chain problem for skillful performance, and I argue that the solution can be extended to (...) solve the Gettier problem and the deviant causal chain problems for perception and intentional action. As I develop my solution to these problems, I also compare it with other solutions to bring out the advantages of my approach. I then explain why the solution generalizes: my solution provides us with an analysis of disposition manifestation, which is the key to ruling out deviance. I conclude by considering objections and giving my replies. (shrink)

An explanation is given of why it is in the nature of inquiry into whether or not p that its aim is fully achieved only if one comes to know that p or to know that not-p and, further, comes to know how one knows, either way. In the absence of the latter one is in no position to take the inquiry to be successfully completed or to vouch for the truth of the matter in hand. An upshot is that (...) although knowledge matters because truth matters this should not be understood to mean that knowledge matters because true belief matters. (shrink)

The paper makes two points. First, any theory of knowledge must explain the difference between cases of knowledge from falsehood and Gettier cases where the subject relies on reasoning from falsehood. Second, the closeness-to-the-truth approach to explaining the difference between knowledge-yielding and knowledge-suppressing falsehoods does not hold up to scrutiny.

According to Lehrer’s defeasibility account of knowledge, we can understand knowledge as undefeated justified true belief. But this account faces many serious problems. One important problem is that from one’s subjective point of view, one can hardly bridge the gap between one’s personal justification and objective truth. Another important problem is that this account can hardly accommodate the externalist intuition that the epistemic status of a belief is not entirely determined by factors that are internal to the subject’s perspective. The (...) goal of this paper is to offer an alternative account of knowledge which can successfully deal with these problems. On the basis of a Sellarsian social practice theory of justification, I argue that we can understand knowledge as objectively justified belief. (shrink)

Alan Millar's paper involves two parts, which I address in order, first taking up the issues concerning the goal of inquiry, and then the issues surrounding the appeal to reflective knowledge. I argue that the upshot of the considerations Millar raises count in favour of a more important role in value-driven epistemology for the notion of understanding and for the notion of epistemic justification, rather than for the notions of knowledge and reflective knowledge.

This article argues for the thesis that the distinction between propositional and doxastic justification should be extended to knowledge. A consequence of this thesis is that there is a type of knowledge that requires belief and a type that does not. A familiar example strikingly similar to the sort of example used to introduce the propositional/doxastic justification makes a prima facie case. Additional theoretical advantages are revealed when the distinction is applied within the context of some recent epistemological debates. These (...) include debates over the knowledge account of assertion, testimonial knowledge, self-deception, and the question of whether knowledge can be essentially based on falsehood. It is contended that the sort of distinction offered here provides a way to settle these debates and, at the same time, acknowledge what is correct in the opposing positions. (shrink)

According to some philosophers who accept a propositional conception of evidence, someone's evidence includes a proposition only if it is true. I argue against this thesis by appealing to the possibility of knowledge from falsehood.

Falsehood can preclude knowledge in many ways. A false proposition cannot be known. A false ground can prevent knowledge of a truth, or so we argue, but not every false ground deprives its subject of knowledge. A falsehood that is not a ground for belief can also prevent knowledge of a truth. This paper provides a systematic account of just when falsehood precludes knowledge, and hence when it does not. We present the paper as an approach to the Gettier problem (...) and arrive at a relatively simple theory with virtues linked to several issues at the heart of contemporary epistemology. (shrink)

This chapter addresses the question of what makes expressions meaningful according to the conception of meaning offered by Donald Davidson. It addresses this question by reflecting on Kathrin Glüer’s recent response to it. It argues that Glüer misconstrues both the evidence for meaning that the radical interpreter must rely on and the way in which the principle of charity must be deployed. The articulation of the correct construal of the evidence and the principle reveals the thoroughly non-reductionist aspect of Davidson’s (...) conception of meaning. This aspect becomes even clearer in his later work, through the articulation of the triangulation argument. I try to show how this argument, which is reconstructed in accordance with Claudine Verheggen’s interpretation of it, helps answer the initial question. The question whether the conception has the resources to account for the objectivity of meaning is briefly discussed. (shrink)

For some of us, the defeasibility theory of knowledge remains the most plausible approach to the Gettier Problem. Epistemological fashion and faded memories notwithstanding, persuasive objections to the theory are very hard to find. The most impressive of those objections to the theory that have hitherto gone unanswered are examined and rejected here. These are objections put forward by Richard Feldman, Richard Foley, and John Turri. While these are all interesting, the objection recently put forward by Turri is, we think, (...) by far, the most serious threat to the theory that we have seen in a long time. A successful reply to it requires a surprising amount of care, as it turns out. If tenable, Turri's objection deals a devastating blow to the theory developed by Roderick Chisholm, Keith Lehrer, Peter Klein, Marshall Swain, Risto Hilpinen, John Pollock, and Paul Moser, among others. Under scrutiny, however, the threat proves illusory. It results from inattention to a crucial, but relatively subtle, aspect of.. (shrink)

There is a clean image of knowledge transmission between thinkers that involves sincere and reliable speakers, and hearers who carefully assess the epistemic credentials of the testimony that they hear. There is, however, a murkier side to testimonial exchange where deception and lies hold sway. Such mendacity leads to sceptical worries and to discussion of epistemic vice. Here, though, I explore cases where deceit and lies are involved in knowledge transmission. This may sound surprising or even incoherent since lying usually (...) involves saying something that is false. Even if a liar unwittingly tells the truth, those believing their testimony would not acquire knowledge. In §1, however, I suggest a range of examples where lies can be used to transmit knowledge. The kinds of cases upon which I focus are those involving ‘engineered knowledge’, where a speaker skilfully manipulates another into having a true belief. Such cases are epistemologically significant for several reasons. First, they are counter-examples to a range of widely held assumptions about knowledge. We have, for example, cases where sincerity is not necessary for knowledge transmission, where there is knowledge from falsehood, and, as we shall discuss in §2, knowledge that is fragile or not safe. Second, in §3 and §4 I suggest that engineered knowledge is best captured by a virtue theoretic approach to testimonial transmission. (shrink)

What do you get when you cross a fallacy with a good argument? A fugu, that is, a valid argument that tempts you to reach its conclusion invalidly. You have yielded to the temptation more than you realize. If you are a teacher, you may have served many fugus. They arise systematically through several mechanisms. Fugus are interesting intermediate cases that shed light on the following issues: bare evidentialism, false pleasure, philosophy of education, and the ethics of argument. Normally, a (...) fugu will not yield knowledge from known premises. But if the reasoning is only slightly fallacious, they do yield knowledge. These mild fugus show that we can gain knowledge by invalid reasoning. This is a conservative resource for historians. They want to credit discoveries to Euclid rather than those who made minor corrections to his proofs, such as David Hilbert. We also benefit from this practice of grandfathering in old standards of knowledge attribution. For we can compete spiritedly for priority. We do not need to worry that credit will instead go to future scholars who will make the minor amendments needed to raise present proofs to a future standard of demonstration. (shrink)

I argue that DeRose's attributor contextualism cannot straightforwardly preserve the widespread view that, when a subject believes q solely on the basis of competent deduction from p, knowledge of q requires knowledge of p. I present a novel challenge to the compatibility of this widespread view with DeRose's contextualism, then argue that the tension can be resolved in only one of two ways: if DeRose rejects the widespread view or if DeRose accepts the existence of a range of contextualism-specific Gettier-style (...) cases. (shrink)

The focus of this paper is the prima facie plausible view, expressed by the principle of Counter-Closure, that knowledge-yielding competent deductive inference must issue from known premises. I construct a case that arguably falsifies this principle and consider five available lines of response that might help retain Counter-Closure. I argue that three are problematic. Of the two remaining lines of response, the first relies on non-universal intuitions and forces one to view the case I construct as exhibiting a justified, true (...) belief to which none of the usual diagnoses of knowledge failure in Gettier cases apply. The second line involves claiming that Fake Barns and its ilk are misdiagnosed by epistemological orthodoxy as Gettier cases. We are thus confronted by a trilemma: either the case I discuss undermines the first-blush plausible principle of Counter-Closure; or the case I discuss instantiates a novel kind of Gettier case; or a popular conception of a key range of alleged Gettier cases must be rejected. No matter which horn we choose, the case points to a philosophically curious conclusion. (shrink)

Alan Millar's paper (2011) involves two parts, which I address in order, first taking up the issues concerning the goal of inquiry, and then the issues surrounding the appeal to reflective knowledge. I argue that the upshot of the considerations Millar raises count in favour of a more important role in value-driven epistemology for the notion of understanding and for the notion of epistemic justification, rather than for the notions of knowledge and reflective knowledge.

I argue that assertion and practical reasoning must be governed by the same epistemic norm. This is because the epistemic rule governing assertion derives from the epistemic rule governing practical reasoning, together with a plausible rule regarding assertion, according to which assertion must manifest belief.

This paper challenges Bird’s view that scientific progress should be understood in terms of knowledge, by arguing that unjustified scientific beliefs (and/or changes in belief) may nevertheless be progressive. It also argues that false beliefs may promote progress.

A epistemologia do testemunho tem reacendido forte interesse entre a classe dos atuais epistemólogos. Tem sido redescoberta a sua indispensabilidade epistêmica e reassumida a posição de que o testemunho é uma fonte de crenças penetrante e natural, no qual muitas das crenças nele fundamentadas constituem conhecimento e estão justificadas. Reducionistas e antirreducionistas se alternam, repetidamente, para explicar o papel epistêmico do testemunho na justificação da crença testemunhal, gerando um acirrado debate na epistemologia contemporânea. Advogada do Reducionismo local, Elizabeth Fricker refuta (...) a relevância da justificação com base no testemunho para crença testemunhal. Com base nisso, este artigo propõe apresentar algumas críticas aos argumentos de refutação reducionista de Fricker quanto à possibilidade epistêmica do testemunho.: The epistemology of testimony has rekindled strong reigniting interest among the train of current epistemologists. Its epistemic indispensability has been unearthed anew and the importance that the testimony is a natural and pervasive source of beliefs has been recaptured as well, considering that many of the beliefs based on itself constitute knowledge and are justified. Reductionists and Anti-Reductionists alternate, repeatedly, explaining the epistemic role of testimony in justification of testimonial belief, generating a heated debate in contemporary epistemology. Reductionism local lawyer, Elizabeth Fricker, refutes the relevance of justification with testimony-based to testimonial belief. Based on that, this paper aims at presenting some criticism to the reductive refutation of Fricker’s arguments as to the epistemic possibility of testimony. Keywords : Epistemology of testimony. Testimonial justification. Local Reductionism. Anti-Reductionism. Inferential Support. (shrink)

On the most prominent account, understanding what was said is always propositional knowledge of what was said. I develop a more minimal alternative, according to which understanding is sometimes a distinctive attitude towards what was said—to a first approximation, entertaining what was said. The propositional knowledge account has been supported on the basis of its capacity to explain testimonial knowledge transmission. I argue that it is not so supported.

This paper argues that three plausible principles are mutually inconsistent: One ought to assert only what one knows; If it is proper to assert some proposition q, then it is, barring special and not very common circumstances, proper to assert any proposition p from which q has been competently inferred; and Some propositions are both properly assertible and known by competent inference from propositions which one does not know. Each pair of two principles constitutes an argument against the remaining principle, (...) but which principle should one drop? (shrink)