With characteristic incisiveness Georg Henrik von Wright identifies pro­ haireticIogic (i. e. the logic of preference) as the core of a general theory of value concepts. Essentially, this nucleus involves the logical study of acts from the point of view of their preferability. 1 (italics added) Though the term prohairesis is found in Plato, as well as in Aristotle's treatment of the relations of preference, it is von Wright who introduces this word into contemporary analytical philoso­ phy, and succinctly specifies (...) the philosophical dimensions it encompasses. The above emphasis upon the philosophical study of the formalization of preferences is a matter of utmost importance for understanding the type of in­ quiry this investigation attempts to initiate. Over the past one hundred years the literature on general theories of subjective utility has become massive, where one considers the work done in psychometrics, econometrics, statistical theories, probability theories, etc., etc. Histories in these areas are strong in tracing various evolutions in the development of the concept of preference in decision-making. However, what has not been investigated with sustained at­ tention are the fundamentally philosophical inquiries into the formalization of preference-relations. (shrink)

Nonmonotonic reasoning in its broadest sense is reasoning to conclusions on the basis of incomplete information. Given more information, previously drawn inferences may be retracted. Commonsense reasoning has a nonmonotonic component; it has been argued that almost all commonsense inferences are of this sort. From the end of the 1980s to the present there has been an explosion in research in nonmonotonic reasoning. It is now possible to understand more clearly the properties of the major formalisms from a metatheoretical point (...) of view, the relationships among the formalisms and their connection to independently developed proof methods. The goal of this monograph is to make this understanding more accessible. (shrink)