The author describes a formal system for interpreting and generating epistemically-qualified judgments, that is, judgments qualified by phrases like “it is certain that,” “it is almost certain that,” “it is plausible that,” and “it is doubtful that.” The system has two noteworthy properties. First, the system’s qualifiers are purely qualitative. Second, the system is based on epistemic warranting conditions, not truth conditions. The first property is noteworthy because it makes the system an alternative to systems that use numerical certainty factors (...) to interpret epistemic qualifiers; unlike these numerically-based systems, the system the author describes is faithful to the surface meanings of epistemic qualifiers. The second property is noteworthy because it makes the system an altemative to deductive systems; unlike deductive systems, the system the author describes supports nonmonotonic inferences. The author’s account includes precise warranting conditions for system-supported judgments, a semantics that fixes the meaning of system judgments, and algorithms for generating system judgments. (shrink)

The author describes a formal system for interpreting and generating epistemically-qualified judgments, that is, judgments qualified by phrases like “it is certain that,” “it is almost certain that,” “it is plausible that,” and “it is doubtful that.” The system has two noteworthy properties. First, the system’s qualifiers are purely qualitative. Second, the system is based on epistemic warranting conditions, not truth conditions. The first property is noteworthy because it makes the system an alternative to systems that use numerical certainty factors (...) to interpret epistemic qualifiers; unlike these numerically-based systems, the system the author describes is faithful to the surface meanings of epistemic qualifiers. The second property is noteworthy because it makes the system an altemative to deductive systems; unlike deductive systems, the system the author describes supports nonmonotonic inferences. The author’s account includes precise warranting conditions for system-supported judgments, a semantics that fixes the meaning of system judgments, and algorithms for generating system judgments. (shrink)

Traditionally scientific rationality has been distinguished from mere practical rationality. It has seemed that it is sometimes rational to accept statements for the purposes of particular practical deliberations even though it would not be rational to count them as having been confirmed by science. Isaac Levi contends that this traditional view is mistaken. He thinks that there should be a single standard of acceptance for all purposes, scientific and practical. The author contends that Levi has given no good reason for (...) identifying scientific with practical rationality. And he argues that Levi's own theory is inconsistent with the thesis that a scientist should use a single standard of acceptance in all his scientific deliberations. (shrink)