Guido Melchior

Bootstrapping and the easy knowledge problem can be understood as puzzles about conflicting intuitions. On one hand, each step of the inference seems correct, but on the other, the overall process seems unacceptable. These puzzles will be resolved by establishing two distinctions. First, untargeted cognitive processes of belief formation must be distinguished from processes of intentional inquiry. Second, conditions on justification transmission must be distinguished from conditions on rationality understood as an internal criterion of coherence. Bootstrapping as a process of settling the question about the reliability of a source violates internal criteria of rationality, but this does not entail that justification cannot transmit via bootstrapping reasoning. The intuitive defectiveness of bootstrapping can be explained in terms of the violation of rules of rationality in contexts of inquiry without being committed to accepting the general defectiveness of bootstrapping in all contexts.

The established view about regress problems has it that they, roughly speaking, come in only one variety. This view is mistaken. Two types of problems are typically subsumed under the label of regress problems – stopping problems and starting problems. Both problem types share the same surface structure in terms of necessary and sufficient conditions, but their deeper founding structure reveals some key differences. Stopping problems rely on a regress clause, raise the question whether infinite chains are possible, and present terminatism, infinitism, and nihilism as potential solutions. In contrast, standard starting problems, which many regress problems are, rely on a founding clause and not on a regress clause, do not raise questions about the possibility of infinite chains, and offer only two potential solutions, terminatism and nihilism. Non-standard starting problems also allow for infinitism as a viable solution, but nevertheless they differ structurally in various aspects from stopping problems.

S is usually assumed to be blameworthy for harmful actions only if S knew or should have known about the harmful consequences of her actions. Since there is usually assumed to be a connection between one’s obligations and one’s capacities, expressed by the slogan that ought implies can, one’s capacities to know have an impact on one’s blameworthiness. In this paper, I will investigate this relationship between blameworthiness and knowledge in reverse order. I will first investigate the meaning of (not) being in a position to know. As I will argue, persons can fail to be in a position to know in two different ways – because they are not in a position to acquire evidence or because they are not in a position to acknowledge existing evidence. I will reflect on different epistemically flawed characters, powerless inquirers, who cannot acquire evidence, psychologically stubborn persons, who fail to believe that p despite acknowledged evidence in favor of p, and misled subjectively rational persons, who form beliefs according their own false beliefs about rationality and evidence. As I will argue, people can be prima facie blamelessly ignorant in multiple ways, and major views on blameworthy ignorance confirm this heterogeneous picture.

The orthodox view about sensitivity and induction has it that beliefs formed via induction are insensitive. Since inductive knowledge is highly plausible, this problem is usually regarded as a reductio argument against sensitivity accounts of knowledge. Some adherents of sensitivity defend sensitivity against this objection, for example by considering backtracking interpretations of counterfactuals. All these extant views about sensitivity and induction have to be revised, since the problem of sensitivity and induction is a different one. Regardless of whether we allow backtracking interpretations of counterfactuals, some instances of induction yield insensitive beliefs whereas others yield sensitive ones. These results are too heterogenous for providing a plausible sensitivity-account of inductive knowledge. Induction remains a serious problem for sensitivity accounts of knowledge.

The proof paradox results from conflicting intuitions concerning different types of fallible evidence in a court of law. We accept fallible individual evidence but reject fallible statistical evidence even when the conditional probability that the defendant is guilty given the evidence is the same, a seeming inconsistency. This paper defends a solution to the proof paradox, building on a sensitivity account of checking and settling a question. The proposed sensitivity account of legal proof not only requires sensitivity simpliciter but sensitivity of each relevant step of the proof procedure and/or sensitivity concerning all relevant alternatives. This account avoids problems that have been identified for other sensitivity views of legal proof. Moreover, it is argued that sensitivity, rather than safety, is the crucial modal condition for legal proof. It is, finally, shown that the provided account can fruitfully support very different existing views on the relationship between knowledge and legal proof.

This paper provides a thorough analysis of two often informally stated claims. First, successful argumentation in the sense of persuasive argumentation requires agreement between the interlocutors about the rationality of arguments. Second, a general agreement about rationality of arguments cannot itself be established via argumentation, since such an attempt leads to an infinite meta‐regress. Hence, agreement about the rationality of arguments is a precondition for successful argumentation. As the paper argues, these plausible claims hold under the assumption that interlocutors are subjectively rational and follow their own standards of rationality when engaging in argumentation.

Questions surrounding deep disagreement have gained significant attention in recent years. One of the central debates is metaphysical, focusing on the features that make a disagreement deep. Proposals for what makes disagreements deep include theories about hinge propositions and first epistemic principles. In this paper, I criticize this metaphysical discussion by arguing that it is methodologically flawed. Deep disagreement is a technical or semi-technical term, but the metaphysical discussion mistakenly treats it as a common-sense concept to be analyzed and captured by our pre-theoretical intuitions. Since the literature on deep disagreement is subject to this fundamental confusion and deep disagreement is not a helpful umbrella term either, I propose eliminating the notion of deep disagreement from the philosophical discourse. Instead of analyzing the nature of deep disagreement, we should develop theories about different forms of disagreement, including disagreement about hinge propositions and disagreement about epistemic principles, and, in particular, a theory of rationally irresolvable disagreement.

That bootstrapping and Moorean reasoning fail to instantiate persuasive argumentation is an often informally presented but not systematically developed view. In this paper, I will argue that this unpersuasiveness is not determined by principles of justification transmission but by two straightforward principles of rationality, understood as a concept of internal coherence. First, it is rational for S to believe the conclusion of an argument because of the argument, only if S believes sufficiently many premises of the argument. Second, if S doubts that a source O is reliable and believes that information i is delivered by O, then S rationally suspends judgment about the truth of i. This paper aims to accomplish two tasks. First, it provides a thorough analysis of why bootstrapping argumentation is not an instance of rational persuasion. Second, it contains a more general theory about preconditions and limits of persuasive argumentation.

In epistemology, the concept of knowledge is of distinctive interest. This fact is also reflected in the discussion of epistemic value, which focuses to a large extend on the value problem of knowledge. This discussion suggests that knowledge has an outstanding value among epistemic standings because its value exceeds the value of its constitutive parts. I will argue that the value of knowledge is not outstanding by presenting epistemic standings of checking, transferring knowledge, and proving in court, whose values exceed the value of knowledge in certain contexts. Moreover, the values of these other epistemic standings do not always rely on the value of knowledge. In terms of value, knowledge is not an outstanding epistemic concept. Hence, in terms of value we cannot find support for the privileged position that knowledge enjoys in epistemology.

The discussion about deep disagreement has gained significant momentum in the last several years. This discussion often relies on the intuition that deep disagreement is, in some sense, rationally irresolvable. In this paper, I will provide a theory of rationally irresolvable disagreement. Such a theory is interesting in its own right, since it conflicts with the view that rational attitudes and procedures are paradigmatic tools for resolving disagreement. Moreover, I will suggest replacing discussions about deep disagreement with an analysis of rationally irresolvable disagreement, since this notion can be more clearly defined than deep disagreement and captures the basic intuitions underlying deep disagreement. I will first motivate this project by critically assessing the current debate about deep disagreement. I then detail the notions of rationality and resolvable disagreement which are crucial for a suitable theory of rationally irresolvable disagreement before sketching various instances of rationally irresolvable disagreement. Finally, I argue for replacing theories of deep disagreement with theories of rationally irresolvable disagreement, an approach that has significant advantages over existing theories of deep disagreement which focus on hinge propositions or fundamental epistemic principles.

This paper provides a reinterpretation of some of the most influential skeptical arguments, Agrippa’s trilemma, meta-regress arguments, and Cartesian external world skepticism. These skeptical arguments are reasonably regarded as unsound arguments about the extent of our knowledge. However, reinterpretations of these arguments tell us something significant about the preconditions and limits of persuasive argumentation. These results contribute to the ongoing debates about the nature and resolvability of deep disagreement. The variety of skeptical arguments shows that we must distinguish different types of deep disagreement. Moreover, the reinterpretation of skeptical arguments elucidates that deep disagreement cannot be resolved via argumentation.

Discrimination is a central epistemic capacity but typically, theories of discrimination only use discrimination as a vehicle for analyzing knowledge. This paper aims at developing a self-contained theory of discrimination. Internalist theories of discrimination fail since there is no compelling correlation between discriminatory capacities and experiences. Moreover, statistical reliabilist theories are also flawed. Only a modal theory of discrimination is promising. Versions of sensitivity and adherence that take particular alternatives into account provide necessary and sufficient conditions on discrimination. Safety in contrast is not sufficient for discrimination as there are cases of safety that are clearly instances of discrimination failure. The developed account of discrimination between objects will be extended to discrimination between kinds and between types.

Sensitivity is a modal epistemic principle. Modal knowledge accounts are externalist in nature and claim that the knowledge yielding connection between a true belief and the truthmaker must be spelled out in modal terms. The sensitivity condition was introduced by Robert Nozick. He suggests that if S knows that p, then S’s belief that p tracks truth. Nozick argues that this truth-tracking relation can be captured by subjunctive conditionals. As a first approximation, he provides the following modal analysis of knowledge: S knows that p iff (1) p is true; (2) S believes that p; (3) if p were false, S wouldn’t believe that p and (4) if p were true, S would believe that p. The dominant terminology in the literature, also adopted here, is to call condition (3) the sensitivity condition and condition (4) the adherence condition. The sensitivity condition is intuitively appealing since it states that a subject does not know that p if she would believe that p even if p were false. Nozick used the sensitivity condition to accomplish two major tasks. First, he provided a solution to the Gettier problem by arguing that in Gettier cases subjects do not know since the sensitivity condition is violated. Second, he presented a controversial solution to the skeptical problem according to which we have external world knowledge but do not know that the skeptical hypothesis is false. This solution is available because sensitivity is not closed under known entailment. Quickly, criticism of the sensitivity condition emerged. First, most epistemologists regarded the price of abandoning knowledge closure as a price too high to pay. Second, it was noted that sensitivity leads to the counterintuitive consequence of precluding us from inductive knowledge since induction typically yields insensitive beliefs. The most dominant reaction to these problems was to replace sensitivity by the modal principle of safety, nowadays the most popular modal principle. However, sensitivity is not only important as a starting point of modal epistemology. Because of its intuitive attractiveness, many authors aimed at refining the original sensitivity account in order to avoid well-known problems. This has led to a second wave of sensitivity accounts. As of today, various sensitivity-based theories are on the market, including accounts that avoid closure failure, probabilistic interpretations of sensitivity and adherence, and contextualist approaches. There is thus a vivid and ongoing debate about the sensitivity principle in epistemology.

Modal knowledge accounts that are based on standards possible-worlds semantics face well-known problems when it comes to knowledge of necessities. Beliefs in necessities are trivially sensitive and safe and, therefore, trivially constitute knowledge according to these accounts. In this paper, I will first argue that existing solutions to this necessity problem, which accept standard possible-worlds semantics, are unsatisfactory. In order to solve the necessity problem, I will utilize an unorthodox account of counterfactuals, as proposed by Nolan, on which we also consider impossible worlds. Nolan’s account for counterpossibles delivers the intuitively correct result for sensitivity i.e. S’s belief is sensitive in intuitive cases of knowledge of necessities and insensitive in intuitive cases of knowledge failure. However, we acquire the same plausible result for safety only if we reject his strangeness of impossibility condition and accept the modal closeness of impossible worlds. In this case, the necessity problem can be analogously solved for sensitivity and safety. For some, such non-moderate accounts might come at too high a cost. In this respect, sensitivity is better off than safety when it comes to knowing necessities.

This paper aims at resolving a puzzle about the persuasiveness of bootstrapping. On the one hand, bootstrapping is not a persuasive method of settling questions about the reliability of a source. On the other hand, our beliefs that our sense apparatus is reliable is based on other empirically formed beliefs, that is, they are acquired via a presumably complex bootstrapping process. I will argue that when we doubt the reliability of a source, bootstrapping is not a persuasive method for coming to believe that the source is reliable. However, when being initially unaware of a source and its reliability, as in the case of forming beliefs about our sense apparatus, bootstrapping can be eventually persuasive.

I argue that intercultural argumentation can only succeed if the same views about rational argumentation dominate in the two cultures. Hence, I will show that the possibilities of successful intercultural argumentation are limited. I will proceed in the following way: First, I will define arguments and argumentation situations. Second, I will investigate the general cases of persons, who in fact are rational in argumentation situations and persons, who believe to be rational. Third, I will illustrate the consequences for both cases. Fourthly, I will apply these general cases to representatives of different cultures i.e. to intercultural argumentation.

The canonical version of external world scepticism has the following structure: Premise1: If P knows that she is not a brain in a vat, then P does not have knowledge of the external world. Premise2: P does not know that she is not a brain in a vat. Conclusion: Therefore, P does not have knowledge of the external world. Some philosophers attack premise1 by denying the underlying closure principle. I will investigate possible argumentations for and against premise2. I will show that premise2 is only true if additional internalistic conditions are fulfilled. I will conclude that the canonical version of the argument is inadequate and that premise1 must be replaced by a stronger internalistic premise. After presenting the adequate argument, I will argue that this internalistic premise contradicts the closure principle underlying premise1. I will conclude that external world scepticism can only hold if the closure principle is rejected.

It is widely hold view that persons have privileged access to their own minds, although there are numerous different views, how it exactly looks like. One possible interpretation of this privilege of first-person-perspective is to regard reference to own mental states as privileged in comparison to reference to mental states of others. I will argue for the existence of an additional privilege of third-person-perspective: Other persons can refer to all mental states of a person in way the person herself cannot. Hence, the possibilities for first-person-reference from a third-person-perspective are limited. In this sense, there also exists a privileged access to other minds.

Sensitivity and safety are modal concepts of knowledge. A person’s belief that p is sensitive if and only if in the closest possible world where p is false S does not believe that p. A person’s belief that p is safe if and only if in most near-by possible worlds in which S continues to form her belief that p in the same way as in the actual world the belief continues to be true. Robert Nozick claims that sensitivity is a necessary condition for knowledge. Ernest Sosa, Timothy Williamson and Duncan Pritchard argue among others that safety is necessary for knowledge. I shall contest both views by offering counterexamples of persons, to whom it is highly plausible to ascribe knowledge although their beliefs are neither sensitive nor safe. I conclude that neither sensitivity nor safety is a necessary condition for knowledge and that insensitive and unsafe knowledge exists.

The skeptic argues that we cannot have any external world knowledge because we cannot know that we are not brains in a vat. The intuitive appeal of this skeptical argument is essentially based on the comprehensibility of the process of skeptical doubting, where we focus our attention on our experiences and experience-based beliefs and raise questions about the sources of these experiences. I propose that skeptical doubting is an instance of a mental attitude that contemporary psychology characterizes as mindfulness. I suggest that mindful self-reflection is not a single phenomenon but rather a cluster of related phenomena that are characterized by an epistemic gap of one kind or the other. I conclude that the persuasiveness of the skeptical argument is based on undergoing the mental process of mindful self-reflection. The undesired skeptical results are gained by overemphasizing the epistemic force of this mental attitude.

(*This paper was awarded the Elisabeth and Werner Leinfellner Award 2017 for outstanding contributions.) This paper provides an explanation of the skeptical puzzle. I argue that we can take two distinct points of view towards representations, mental representations like perceptual experiences and artificial representations like symbols. When focusing on what the representation represents we take an attached point of view. When focusing on the representational character of the representation we take a detached point view. From an attached point of view, we have the intuition that we can know that p simply by using the representation and without having prior knowledge about the reliability of the source that delivers the representation. When taking a detached point of view, we tend to think that we must have this kind of prior knowledge. These two conflicting intuitions about knowledge and representations provide the basis for our intuition of immediate perceptual knowledge on the one hand and for the skeptical intuition of underdetermination on the other hand.