Epistemic Defeaters

You reach for the bowl with ‘sugar’ written on it only to discover, from the bad taste of your coffee, that it contained salt. Mundane experiences like these show that epistemic justification does not necessarily hold stable across possible changes of information. One can be justified in believing a proposition at a certain time (that the bowl contains sugar) and cease to be justified at a later time, as one enlarges one’s epistemic perspective (as one drinks a salty coffee). When this happens, one’s justification has been defeated. An epistemic defeater, broadly speaking, is that in terms of which the defeat of justification proceeds. The notion of an epistemic defeater is mostly associated with J. Pollock’s work on reasoning and inference. Pollock has provided the canonical definition of an epistemic defeater and proposed an influential taxonomy in terms of the way different types of defeaters induce their characteristic effects. The notion of an epistemic defeater has acquired a broader meaning in current epistemology, and several distinctions have been introduced that have contributed to a more nuanced understanding of the phenomenon of defeat as well as to complement Pollock’s original taxonomy. The correlated notion of a propositional defeater, defined in terms of would-be defeat of justification, is appealed to by the proponents of the defeasibility theory in the parallel debate about knowledge to explain what prevents a justified true belief from constituting knowledge in Gettier cases

A Virtue Reliabilist Error-Theory of Defeat

Peer reviewe

Undercutting Defeat: When it Happens and Some Implications for Epistemology

Although there is disagreement about the details, John Pollock’s framework for defeat is now part of the received wisdom in analytic epistemology. Recently, however, cracks have appeared in the consensus, particularly on the understanding of undercutting defeat. While not questioning the existence of undercutting defeat, Scott Sturgeon argues that undercutting defeat operates differently from rebutting. Unlike the latter, undercutting defeat, Sturgeon claims, occurs only in conjunction with certain higher-order contributions, i.e., with beliefs about the basis on which one does or would believe. Sturgeon concludes that Pollock misconceives undercutting defeat. I argue that in the case of defeat of inferential justification, undercutting defeat is a genuine phenomenon and takes roughly the shape Pollock suggests, not needing help from higher-order beliefs or justifications. However, I agree with Sturgeon that for noninferential justification the Pollockian account is in trouble. I try to explain why there should be this difference. This difference in defeaters has important implications for epistemology. In a final section, I use the defeat-related difference between inferential and noninferential justification to argue that there is less noninferential perceptual or testimonial justification than is commonly thought

The Evolution of Defeaters: A Taxonomy

It has been widely argued that reasons for a belief come in degrees but not much literature has focused on the idea that defeaters for justification toward those beliefs also come in degrees. The aim of this paper is to explore epistemic defeasibility and construct a taxonomy for epistemic defeaters. This paper argues that epistemic defeaters undergo an evolutionary process before becoming what they are commonly labeled, such as rebutting and undercutting. I argue that within some stages of this process, there can be different degrees of defeat. This paper focuses on defeaters for justification, expands on the account of partial defeaters and offers a solution to reliabilism’s problem with defeat. The main aim of this taxonomy is to provide a framework that allows (most) epistemic theories to accept solely on the basis of epistemic defeasibility

Pollock and Sturgeon on defeaters

Scott Sturgeon has recently challenged Pollock’s account of undercutting defeaters. The challenge involves three primary contentions: (1) the account is both too strong and too weak, (2) undercutting defeaters exercise their power to defeat only in conjunction with higher-order beliefs about the basis of the lower-order beliefs whose justification they target, and (3) since rebutting defeaters exercise their power to defeat in isolation, rebutting and undercutting defeaters work in fundamentally different ways. My goal is to reject each of these contentions. I maintain that (1) Sturgeon fails to show that Pollock’s account of undercutting defeaters is either too strong or too weak, (2) his own account of how undercutting defeaters exercise their power to defeat is both too strong and too weak, and (3) his claim that rebutting and undercutting defeaters work in fundamentally different ways is mistaken

Knowledge as adequately informed process

An important lesson learned from the widely-known Gettier cases in epistemology is that no matter how well-justified our beliefs are, knowledge can never be secured— for there could always be some information unbeknownst to us that would undermine our epistemic statuses. In the thesis, I devise a specific approach to epistemic evaluations addressing this problem—inspired by Richard Foley’s (2012) ecumenical account of adequate information on knowledge, as well as Crispin Wright’s (1993, 1994) notion of super-assertibility on truth. In a nutshell, I suggest that one knows just in case one’s belief forming process remains intact upon any expansion of information regarding the epistemic situation. Call this the adequately informed process view on knowledge (AP). Reflecting the interplay between cognitive agency and the external world in the notion of knowledge, the AP account is twofold. On the one hand, it requires a specific display of cognitive process on the agent’s part. Particularly, the belief-forming process must be one such that, an ideal epistemic agent following all relevant epistemic norms would consider it acceptable to form the target belief via that process. Call this epistemic standard acceptable ideality. On the other hand, such acceptable ideality needs to take into account all relevant information available in the case, such that one’s process is deemed acceptably ideal overall in lights of everything that holds in the world. The proposed account of AP adopts a holistic and ecumenical approach to epistemic evaluations. Firstly, I champion the idea that epistemic phenomena are what I call “gestalt phenomena”, in that the epistemic significance of the entire epistemic situation cannot be fully appreciated by individually evaluating the significance of its constituents (such as beliefs, justification, cognitive processes etc.). Instead, any impacts of particular epistemic components should be put under the context of the entire epistemic situation for evaluation. Following such a view, I discuss a few examples of how taking the overall knowledge evaluations as merely consisting in its individual epistemic components has created problems for some of the existing accounts of knowledge—and how taking a holistic perspective might shed light on the situation. Secondly, following Foley, I maintain that knowledge in its nature is ecumenical. The main idea is that while there is only one concept of knowledge—characterised by AP as meeting the acceptable ideality standard considering all available information— there can be many ways to achieve such an epistemic standard (in that one’s cognitive agency can be acceptably ideal for various reasons). AP does not champion any particular epistemic feature as constituting knowledge by itself. Some agency would score better on having certain epistemic goods and some on others. According to AP, S’s belief is adequate if the belief forming process’ “overall score” of ideality given all available information is acceptable. The thesis consists of three parts. Part 1 (Chapters 1 and 2) consists of the introduction of the two approaches and articulation of my positive view. Part 2 (Chapters 3 and 4) consists of theoretical comparisons and further motivations for holism in epistemic evaluations. Part 3 (Chapters 5 and 6) consists of applications of the proposed theoretical framework and its ecumenical nature of epistemic evaluations

A defence of the evolutionary debunking argument

In this thesis, I will explore the epistemological evolutionary debunking arguments in meta-ethics (EDA). I will defend these arguments by accomplishing two tasks: (1) I will offer the best (i.e., most detailed and precise) way to understand the EDA and (2) I will also respond to two strongest objections to the EDA. Firstly, in Part I of this thesis, I will offer my account of how the EDA should be best formulated. I will start from how evolution has significantly influenced our moral beliefs. I will then explain why, due to their evolutionary origin, our moral beliefs are not tracking the moral truth reliably. Furthermore, I will argue that the fact that our moral beliefs are not tracking the moral truth also provides an undercutting and a higher-order defeater for those beliefs. As a result, I will conclude that the epistemic status of our moral beliefs is undermined because of these two kinds of defeaters. Secondly, in Part II of this thesis, I will turn my attention to the two strongest objections to the EDA – the Conceptual Truth Objection and the Third Factor Objection. I will first offer two responses to the Conceptual Truth Objection and, based on these two responses, I will argue that the Conceptual Truth Objection fails as a challenge to the EDA. I will then also argue that there currently doesn’t exist an acceptable version of the Third Factor Objection and it is also unlikely that such a version could be constructed in the future. I will finally conclude that both objections are problematic and they are thus unable to give us reason to doubt the EDA