Knowledge Acknowledged: Knowledge of Propositions vs. Knowledge of Objects

Abstract

Listen

Translate article

There is a largely unacknowledged revolution in progress in epistemology. For the first time, theorists of knowledge have access to a fully explicit logical and semantical analysis of the concept of knowledge that does justice to its nature and function and to its different varieties. The reasons for the inconspicuousness of the revolution are partly bibliographical, in that the crucial new insights have been published only sketchily. Another reason is that this is a revolution in Jefferson's sense rather than Lenin's. It changes our outlook, but it does so by building on the concrete achievements reached earlier. The new sharper analysis of the concept of knowledge (including its aspects and its varieties) can be formulated in the form of an improved epistemic logic.' The germ of this new epistemic logic lies in the recognition and the correction of a mistake or, more accurately speaking, an unnecessary restriction that has beset contemporary logic in general, including earlier versions of epistemic logic. One way of looking at this mistake is to say that it concerns the most abstract and most neglected notion in logic, the notion of scope.2 Even though virtually everybody takes this notion for granted, it is not unproblematic. It is viciously ambiguous when used in connection with quantifiers or quantifier-like concepts. As scope is currently expressed by means of parentheses (or equivalent), it involves an attempt to express two entirely different and sometimes divergent notions by means of a single notational device. On the one hand, the nesting of quantifier scopes indicates the relative logical priority of different quantifiers. On the other hand, the scope of a quantifier is supposed to indicate also the segment of a sentence (or a dis-