Rational Belief

This chapter generalizes the modal theory of subjective reasons to the epistemic domain and combines it with the first-order commitment that truth is the sole right-maker for belief. The result is a modal account of epistemic rationality, according to which there is a safety condition on rational belief distinct from but mirroring the more familiar safety condition on knowledge. The chapter shows that the account delivers plausible closure principles on rational belief and offers a straightforward resolution of the lottery paradox. It also explores the implications of the view for whether it is rational to believe necessary propositions, preface propositions, and Moorean propositions.

Knowledge

This chapter generalizes the modal theory of possessed reasons to the epistemic domain and combines it with the first-order commitment that truth is the sole right-maker for belief. A fact is a reason for believing a proposition only if, in nearby metaphysically possible worlds in which that fact obtains, the proposition is true. A person possesses that fact as a reason for believing a proposition only if, in nearby epistemically possible worlds in which that fact obtains, the proposition is true. This is an anti-luck or safety condition on possession. The chapter goes on to argue that, if a person possesses a reason for believing a proposition, they are in a position to know it. It shows that this claim is not vulnerable to Gettier-style counterexamples and that it vindicates the idea that knowledge is a norm of belief, an idea supported by reflection on lottery cases and Moorean beliefs.

Evaluation of ANSI Z535 Safety Sign Installation

A safety sign is a sign of equipment to provide protection for workers or visitors in the workplace. American National Standards Institute Z535 (ANSI Z535) is used as a basic guideline for installing safety signs in the workplace because it is more communicative by using global symbols to overcome language barriers. Occupational Safety Division of Manpower and Transmigration Departement, East Java Province (UPT Keselamatan Kerja Surabaya) is a workplace that has a risk of occupational accidents. The preliminary surveys in the area of the 3rd floor of the Division of Occupational Safety (UPT Keselamatan Kerja) Surabaya revealed that there were many sites with insufficient safety signboards. Many of the installed safety signs did not comply with ANZI Z535 standards. This study aimed to evaluate the installation of safety signs compared to the ANZI Z535 standard on the 3rd floor of UPT K2 Surabaya. This was an observational study examining the installation of safety signs. The data were obtained using the ANSI Z535 safety sign checklist. We found 2 out of 5 types of safety signs were in accordance with ANSI safety sign standards with a comparison percentage of more than 66%, such as the notice sign (67.85%) and safety condition sign (75%). Three other types of safety signs were in the unfavorable category with a percentage of less than 66%, such as danger sign (65.63%), warning sign (50%), and caution sign (46.88%). Some sites required additional safety signs, such as warning signs (at distillation site), caution signs (oven, stairs), notice signs (cylinder storage, elevator, chemical warehouse), and safety condition signs (stair, eyewash).

Bounded Predicates in Description Logics with Counting

Description Logics (DLs) support so-called anonymous objects, which significantly contribute to the expressiveness of these KR languages, but also cause substantial computational challenges. This paper investigates reasoning about upper bounds on predicate sizes for ontologies written in the expressive DL ALCHOIQ extended with closed predicates. We describe a procedure based on integer programming that allows us to decide the existence of upper bounds on the cardinality of some predicate in the models of a given ontology in a data-independent way. Our results yield a promising supporting tool for constructing higher quality ontologies, and provide a new way to push the decidability frontiers. To wit, we define a new safety condition for Datalog-based queries over DL ontologies, while retaining decidability of query entailment.

A Dilemma for Globalized Safety

The safety condition is supposed to be a necessary condition on knowledge which helps to eliminate epistemic luck. It has been argued that the condition should be globalized to a set of propositions rather than the target proposition believed to account for why not all beliefs in necessary truths are safe. A remaining issue is which propositions are relevant when evaluating whether the target belief is safe or not. In the literature, solutions have been proposed to determine the relevance of propositions. This paper examines a case of luckily true belief—thus a case of ignorance—and a case of knowledge. It argues that no solution in the literature offers a correct verdict in either case. Therefore, the strategy to globalize safety remains unsatisfactory.

An appraisal of the evolution of some of the main themes in Sosa’s epistemology

In this article, I propose to trace the evolution of three central concepts in Sosa’s epistemology: the distinction between animal and reflective knowledge, closure principles, and the safety condition. These three planks played a central role in the early presentations of Sosa’s epistemology, but have recently undergone interesting changes.

Research on Safety performance Evaluation method of Portal Crane based on Reliability Evaluation and Risk Assessment

In recent decades, with the vigorous development of shipping and transportation logistics industry, a large number of portal cranes have been installed in the ports of our country for production, and some of the equipment has approached or even exceeded its designed service life, and there is a great hidden danger of safety in the continued use of the equipment. This paper discusses a safety performance evaluation method of portal crane based on analytic hierarchy process (AHP). Through the determination and measurement of evaluation index, the safety condition of equipment can be obtained. according to the value of equipment safety condition, the safety performance can be classified, and the user and management organization can respond effectively according to the safety performance level of equipment, and the risk caused by long-term service of equipment can be effectively eliminated.

Is epistemic safety threatened by Frankfurt cases? A reply to Kelp

I intend to argue that the counterexamples inspired by the Frankfurt-type cases against the necessity of an epistemic safety condition for knowledge are not plausible. The epistemic safety condition for knowledge is a modal condition recently supported by Sosa (2007) and Pritchard (2015), among others, and can be formulated as follows: (SC) If S knows that p on basis B, then S’s true belief that p could not have easily been false on basis B. I will try to argue that the safety condition, expressed in (SC), is still necessary for knowledge and that, therefore, epistemic safety is not threatened by Frankfurt-type cases. In particular, I want to show that Kelp’s counterexamples are ineffective against (SC).