Tim Kraft

The negation thesis concerning ignorance ("Nichtwissen") states that someone is ignorant about p if and only if she is does not know that p, or briefly, that ignorance is the negation of knowledge. We argue that there are no compelling arguments against the negation thesis. Even though, depending on the context of the conversation, the focus of an ascription of ignorance will be on one of the conditions for knowledge, all four types of ignorance are possible: ignorance due to falsity, ignorance due to lack of belief, ignorance due to lack of justification, and ignorance due to epistemic luck. Then we discuss the relevance of the distinction between known unknowns and unknown unknowns, and the surprising idea that every strong belief may be identified with an unknown unknown. A desire not to know can be present for a variety of reasons. It may be either symmetrical (not wanting to know whether p) or asymmetrical (not wanting to know that p if p should be true). We argue for the thesis that the desire not to know usually amounts to a desire to preserve the epistemic status quo. The potential applications of these distinctions to the alleged right not to know particularly in medical contexts are largely left open in this paper.

Although the underrepresentation of women in academic philosophy is well-known and hard to overlook, philosophers started to pay more attention to the actual data on and potential explanations of the underrepresentation of women in philosophy only in the last decade and predominately in anglophone countries. The data I present in this paper deal with introductory logic courses at German universities (gender of textbook authors, gender of logic course instructors, student grades by gender at one university). Two results are particularly noteworthy: For one, logic teaching in Germany is currently predominantly male and even more male than philosophy teaching as a whole. For another, there is no evidence for any differences between grades of female and male students. The student grade data, however, illustrate how statistical phenomena like Simpson's paradox can explain how male students can appear to achieve better grades than female students even if there is no underlying difference: When correcting for students’ major (philosophy vs. STEM), logic grades of male and female students are remarkably similar. Although the scope of the data presented here is limited, they allow to add further details to an emerging map of the profession. I close with some suggestions for avoiding stereotyping logic as “male”.

Putnam's argument that we are not brains in a VAT has recently seen a resurgence in interest. Although objections to it are legion, an emerging consensus seems to be that even if it successfully refutes one version of the brain in a VAT scenario, lifelong envatment, it is powerless against a different one, recent envatment. Although initially appealing, I argue in this paper that this response-merely replacing lifelong envatment by recent envatment-is a bad response to Putnam's argument. Yet there is a different version of the brain in a VAT scenario, recent memory-altering envatment, that Putnam's argument does not refute and is also sufficiently radical. The crucial issue turns out to be which epistemic sources sceptical scenarios may attack. I argue that there's no convincing reason for exempting memory from the sceptical attack: Sceptical scenarios must target memory to be sufficiently radical and they can do so without violating any constraint on sceptical scenarios. In the end Putnam's argument doesn't fail because of some 'deep' philosophical mistake, but because it overlooks how flexible and adjustable sceptical scenarios are.

The relation of scepticism to infallibilism and fallibilism is a contested issue. In this paper I argue that Cartesian sceptical arguments, i.e. sceptical arguments resting on sceptical scenarios, are neither tied to infallibilism nor collapse into fallibilism. I interpret the distinction between scepticism and fallibilism as a scope distinction. According to fallibilism, each belief could be false, but according to scepticism all beliefs could be false at the same time. However, to put this distinction to work sceptical scenarios have to be understood as ignorance-possibilities, not as error-possibilities. To show that scepticism is not tied to infallibilism I reject the principle of unrestricted relevance according to which any error- or ignorance-possibility whatsoever is relevant. Instead I argue that the sceptic should distinguish between local and global ignorance-possibilities. Global ignorance-possibilities are relevant even though not all ignorance-possibilities are relevant. The result is a refined version of the Cartesian sceptical argument that avoids two traps other versions do not avoid.

What is the role of sceptical scenarios—dreams, evil demons, brains in a vat—in scep- tical arguments? According to the error view, sceptical scenarios illustrate the possibil- ity of massive falsity in one’s beliefs, whereas according to the ignorance view, they illustrate the possibility of massive ignorance not necessarily due to falsity. In this paper, the ignorance view is defended by surveying the arguments in favour of it and by replying to two pressing objections against it. According to the first objection, the ignorance view illicitly introduces the kk-principle into sceptical arguments. In reply I argue that kk is not less plausible than its main rival, the closure principle. According to the second objection, relying on veridical ignorance-possibilities contradicts the transparency of belief. In reply I introduce a version of transparency that is consistent with the ignorance view.

On a common view of scenario-based sceptical arguments sceptical scenarios are error-possibilities, i.e. their point is to introduce the possibility of having only false beliefs. However, global error is impossible for purely logical/conceptual reasons: Even if one’s beliefs are consistent, the negations of one’s beliefs need not be consistent as well. My paper deals with the question of what the consequences of this result are. Two attempts at repairing scenario-based sceptical arguments within the framework of understanding sceptical scenarios as error-possibilities are found wanting. Instead, what should be given up is the assumption that sceptical scenarios are error-possibilities. What is thought-provoking about the scenario of the brain in a vat is not that none of its empirical beliefs are true, but that all of its empirical beliefs fall short of knowledge at the same time. Hence, sceptical scenarios are not error-possibilities, but ignorance possibilities. If this is so, both the closure argument and the underdetermination argument commit a subtle mistake and should be replaced by slightly different arguments. The principle of excluded ignorance-possibilities turns out to be an epistemological principle that is faithful to scepticism’s tenets without misinterpreting sceptical scenarios as error-possibilities

Epistemological disjunctivism, as defended by, for example, McDowell, Neta and Pritchard, is the view that epistemic justification can be – and in paradigmatic cases of perceptual knowledge actually is – both factive and reflectively accessible. One major problem for this view is the access problem: apparently, epistemological disjunctivism entails that ordinary external world propositions can be known by reflection alone. According to epistemological disjunctivism, seeing that the sun is shining is reflectively accessible and seeing that the sun is shining entails that it is. Assuming closure of reflective knowledge under known entailment it is also reflectively knowable that the sun is shining. Drawing on joint work with Neta, Pritchard replies that disjunctivism is not committed to this absurdity, but only to the possibility of reflective access to empirical reasons. In this article I offer an interpretation of this reply, but also an objection to it: my interpretation is based on applying the source/content distinction to epistemic reasons. My objection is based on arguing that the access problem is a problem for any version of access internalism. Although Pritchard's reply solves the general access problem, it does not solve the access problem that is generated by the specific commitments of epistemological disjunctivism. Due to the transparency of self-knowledge of propositional perception, epistemological disjunctivism cannot meet a central requirement for applying the source/content distinction

Transmission arguments against closure of knowledge base the case against closure on the premise that a necessary condition for knowledge is not closed. Warfield argues that this kind of argument is fallacious whereas Brueckner, Murphy and Yan try to rescue it. According to them, the transmission argument is no longer fallacious once an implicit assumption is made explicit. I defend Warfield’s objection by arguing that the various proposals for the unstated assumption either do not avoid the fallacy or turn the central premise of the transmission argument, namely that a necessary condition is not closed, into a redundant and superfluous premise. I conclude that Warfield’s advice is still to be heeded: Arguments against closure must not rely essentially on the premise that a necessary condition for knowledge is not closed

In Knowledge and its Limits (2000) Williamson defends not only the negative claim that knowledge cannot be analysed, but also the positive claim that knowledge is the most general factive mental state. In this paper two objections to the positive claim are presented: First, knowledge is not more general than e. g. seeing. After discussing several alleged examples of seeing without knowing a new example is offered. Although both seeing and knowing are incompatible with luck, they are incompatible with different kinds of luck. Secondly, factive mental states that are more general than knowledge are conceivable. Williamson's characterisation of knowledge as being the most general factive mental state is not substantial enough to pick out exactly one state. The idea that there is such a thing as a maximal factive mental state cannot be sustained merely on the assumption that knowledge is unanalysable.

One of the unconventional features of Wittgenstein’s _Tractatus Logico-Philosophicus_ is its use of an elaborated and detailed numbering system. Recently, Bazzocchi, Hacker und Kuusela have argued that the numbering system means that the _Tractatus_ must be read and interpreted not as a sequentially ordered book, but as a text with a two-dimensional, tree-like structure. Apart from being able to explain how the _Tractatus_ was composed, the tree reading allegedly solves exegetical issues both on the local and the global level. This paper defends the sequential reading against the tree reading. After presenting the challenges generated by the numbering system and the two accounts as attempts to solve them, it is argued that Wittgenstein’s own explanation of the numbering system, anaphoric references within the _Tractatus_ and the exegetical issues mentioned above do not favour the tree reading, but a version of the sequential reading. This reading maintains that the remarks of the _Tractatus_ form a sequential chain: The role of the numbers is to indicate how remarks on different levels are interconnected to form a concise, surveyable and unified whole.