Michael Shaffer

Following the standard practice in sociology, cultural anthropology and history, sociologists, historians of science and some philosophers of science define scientific communities as groups with shared beliefs, values and practices. In this paper it is argued that in real cases the beliefs of the members of such communities often vary significantly in important ways. This has rather dire implications for the convergence defense against the charge of the excessive subjectivity of subjective Bayesianism because that defense requires that communities of Bayesian inquirers share a significant set of modal beliefs. The important implication is then that given the actual variation in modal beliefs across individuals, either Bayesians cannot claim that actual theories have been objectively confirmed or they must accept that such theories have been confirmed relative only to epistemically insignificant communities

It is a commonplace belief that many beliefs, e.g. religious convictions, are a purely private matter, and this is meant in some way to serve as a defense against certain forms of criticism. In this paper it is argued that this thesis is false, and that belief is really often a public matter. This argument, the publicity of belief argument, depends on one of the most compelling and central thesis of Peircean pragmatism. This crucial thesis is that bona fide belief cannot be separated from action. It is then also suggested that we should accept a form of W. K. Clifford's evidentialism. When these theses are jointly accepted in conjunction with the basic principle of ethics that it is prima facie wrong to act in such a way that may subject others to serious but unnecessary and avoidable harm, it follows that many beliefs are morally wrong.

In a recent article, Peter Gärdenfors (1992) has suggested that the AGM (Alchourrón, Gärdenfors, and Makinson) theory of belief revision can be given an epistemic basis by interpreting the revision postulates of that theory in terms of a version of the coherence theory of justification. To accomplish this goal Gärdenfors suggests that the AGM revision postulates concerning the conservative nature of belief revision can be interpreted in terms of a concept of epistemic entrenchment and that there are good empirical reasons to adopt this view as opposed to some form of foundationalist account of the justification of our beliefs. In this paper I argue that Gärdenfors’ attempt to underwrite the AGM theory of belief revision by appealing to a form of coherentism is seriously inadequate for several reasons.

Stalnaker argued that conditional excluded middle should be included in the principles that govern counterfactuals on the basis that intuitions support that principle. This is because there are pairs of competing counterfactuals that appear to be equally acceptable. In doing so, he was forced to introduced semantic vagueness into his system of counterfactuals. In this paper it is argued that there is a simpler and purely epistemic explanation of these cases that avoids the need for introducing semantic vagueness into the semantics for counterfactuals.

Recently a number of variously motivated epistemologists have argued that knowledge is closely tied to practical matters. On the one hand, radical pragmatic encroachment is the view that facts about whether an agent has knowledge depend on practical factors and this is coupled to the view that there is an important connection between knowledge and action. On the other hand, one can argue for the less radical thesis only that there is an important connection between knowledge and practical reasoning. So, defenders of both of these views endorse the view that knowledge is the norm of practical reasoning. This thesis has recently come under heavy fire and a number of weaker proposals have been defended. In this paper counter-examples to the knowledge norm of reasoning will be presented and it will be argued that this viewand a number of related but weaker viewscannot be sustained in the face of these counter-examples. The paper concludes with a novel proposal concerning the norm of practical reasoning that is immune to the counter-examples introduced here.

In this paper it is argued that the conjunction of linguistic ersatzism, the ontologically deflationary view that possible worlds are maximal and consistent sets of sentences, and possible world semantics, the view that the meaning of a sentence is the set of possible worlds at which it is true, implies that no actual speaker can effectively use virtually any language to successfully communicate information. This result is based on complexity issues that relate to our finite computational ability to deal with large bodies of information and a strong, but well motivated, assumption about the cognitive accessibility of meanings of sentences ersatzers seem to be implicitly committed to. It follows that linguistic ersatzism, possible world semantics, or both must be rejected.

In a recent revision (chapter 4 of Nowakowa and Nowak 2000) of an older article Leszek Nowak (1992) has attempted to rebut Niiniluoto’s 1990 critical suggestion that proponents of the Poznań idealizational approach to the sciences have committed a rather elementary logical error in the formal machinery that they advocate for use in the analysis of scientific methodology. In this paper I criticize Nowak’s responses to Niiniluoto’s suggestion, and, subsequently, work out some of the consequences of that criticism for understanding the role that idealization plays in scientific methodology.

Following Nancy Cartwright and others, I suggest that most (if not all) theories incorporate, or depend on, one or more idealizing assumptions. I then argue that such theories ought to be regimented as counterfactuals, the antecedents of which are simplifying assumptions. If this account of the logic form of theories is granted, then a serious problem arises for Bayesians concerning the prior probabilities of theories that have counterfactual form. If no such probabilities can be assigned, the the posterior probabilities will be undefined, as the latter are defined in terms of the former. I argue here that the most plausible attempts to address the problem of probabilities of conditionals fail to help Bayesians, and, hence, that Bayesians are faced with a new problem. In so far as these proposed solutions fail, I argue that Bayesians must give up Bayesianism or accept the counterintuitive view that no theories that incorporate any idealizations have ever really been confirmed to any extent whatsoever. Moreover, as it appears that the latter horn of this dilemma is highly implausible, we are left with the conclusion that Bayesianism should be rejected, at least as it stands.

In this article the standard philosophical method involving intuition-driven conceptual analysis is challenged in a new way. This orthodox approach to philosophy takes analysanda to be the specifications of the content of concepts in the form of sets of necessary and sufficient conditions. Here it is argued that there is no adequate account of what necessary and sufficient conditions are. So, the targets of applications of the standard philosophical method so understood are not sufficiently well understood for this method to be dependable

Recently Timothy Williamson (2007) has argued that characterizations of the standard (i.e. intuition-based) philosophical practice of philosophical analysis are misguided because of the erroneous manner in which this practice has been understood. In doing so he implies that experimental critiques of the reliability of intuition are based on this misunderstanding of philosophical methodology and so have little or no bearing on actual philosophical practice or results. His main point is that the orthodox understanding of philosophical methodology is incorrect in that it treats philosophical thought experiments in such a way that they can be “filled in” in various ways that undermines their use as counter-examples and that intuition plays no substantial role in philosophical practice when we properly understand that methodology as a result of the possibility of such filling in. In this paper Williamson’s claim that philosophical thought experiments cases can be legitimately filled in this way will be challenged and it will be shown that the experimental critique of the intuition-based methods involved a serious issue.

The ontology of decision theory has been subject to considerable debate in the past, and discussion of just how we ought to view decision problems has revealed more than one interesting problem, as well as suggested some novel modifications of classical decision theory. In this paper it will be argued that Bayesian, or evidential, decision-theoretic characterizations of decision situations fail to adequately account for knowledge concerning the causal connections between acts, states, and outcomes in decision situations, and so they are incomplete. Second, it will be argues that when we attempt to incorporate the knowledge of such causal connections into Bayesian decision theory, a substantial technical problem arises for which there is no currently available solution that does not suffer from some damning objection or other. From a broader perspective, this then throws into question the use of decision theory as a model of human or machine planning.

The main question addressed in this paper is whether some false sentences can constitute evidence for the truth of other propositions. In this paper it is argued that there are good reasons to suspect that at least some false propositions can constitute evidence for the truth of certain other contingent propositions. The paper also introduces a novel condition concerning propositions that constitute evidence that explains a ubiquitous evidential practice and it contains a defense of a particular condition concerning the possession of evidence. The core position adopted here then is that false propositions that are approximately true reports of measurements can constitute evidence for the truth of other propositions. So, it will be argued that evidence is only quasi-factive in this very specific sense

This book is addresses a topic that has received little or no attention in orthodox epistemology. Typical epistemological investigation focuses almost exclusively on knowledge, where knowing that something is the case importantly implies that what is believed is strictly true. This condition on knowledge is known as factivity and it is, to be sure, a bit of epistemological orthodoxy. So, if a belief is to qualify as knowledge according to the orthodox view it cannot be false. There is also an increasingly influential group of epistemologists who argue that one ought to act only on what one knows, because truth of belief is the surest way to guarantee that our actions work out as planned. They defend what is known as the knowledge norm for action. This view is typically justified in virtue of the idea that successful intentional action should stem from knowledge because knowledge is a factive propositional attitude and it is, as a result, success-prone with respect to intentional action. In other words, true beliefs that constitute knowledge are the rationally normative standard for successful acting. But, there are clearly multitudes of cases where epistemic agents operate successfully and even rationally on the basis of beliefs that are false. That this is the case is not especially controversial. Sometimes false beliefs facilitate successful action. Of course, this can be because the agent is simply lucky. However, there is something particularly important about some false beliefs that relates to successful action but not in virtue of luck. While not strictly true, the beliefs in question are close to the truth or approximately true. This gives rise to the possibility that there are knowledge-like states that play roles very similar to knowledge but which are only quasi-factive. That is to say such states imply approximate truth and do not imply strict truth. Moreover, often such beliefs facilitate successful action in virtue of their being approximately true and this suggests a much more plausible norm for successful action that encompasses both cases of rational action guided by such quasi-factive states as well as cases of rational action guided by knowledge. The thesis of this book is that quasi-factive knowledge-like states are far more common that epistemologists have acknowledge and the book introduces a theory of such states and how they give rise to a much more reasonable account of the norms for action. This involves some tricky issues concerning approximate truth, the rationality of believing not strictly true claims, the justification of approximately true beliefs, the nature of false but approximately true evidence, the norms of belief, knowledge and quasi-knowledge, etc.