This dissertation is on infinite regress arguments in philosophy. Its main goals are to explain what such arguments from many distinct philosophical debates have in common, and to provide guidelines for using and evaluating them. Two theories are reviewed: the Paradox Theory and the Failure Theory. According to the Paradox Theory, infinite regress arguments can be used to refute an existentially or universally quantified statement (e.g. to refute the statement that at least one discussion is settled, or the statement that (...) discussions are settled only if there is an agreed-upon criterion to settle them). According to the Failure Theory, infinite regress arguments can be used to demonstrate that a certain solution fails to solve an existentially or universally quantified problem (e.g. to demonstrate that a certain solution fails to settle all discussions, or that it fails to settle even one discussion). In the literature, the Paradox Theory is fairly well-developed, and this dissertation provides the Failure Theory with the same tools. (shrink)

Claims that necessary and sufficient conditions are not converse relations are discussed, as well as the related claim that If A, then B is not equivalent to A only if B . The analysis of alleged counterexamples has shown, among other things, how necessary and sufficient conditions should be understood, especially in the case of causal conditions, and the importance of distinguishing sufficient-cause conditionals from necessary-cause conditionals. It is concluded that necessary and sufficient conditions, adequately interpreted, are converse relations in (...) all cases. (shrink)

The expressions sufficient condition and necessary condition are frequently used in various areas in sciences as well as in everyday usage; therefore, they might be taken as expressing well defined notions which should not lead to any serious misunderstandings when used. According to the widely accepted definitions of both concepts, the concept of sufficient condition and that of necessary condition imply their symmetry : if one thing poses a sufficient condition to another thing, the latter is a necessary condition for (...) the former; however, this symmetry is hardly intuitive and it is refused by many scholars. Given the analyses of practical examples and a symmetry concept defence test, one may conclude that this view is unfounded. As a result, the definitions of the two notions are not determined enough and so is the question whether there is just a single pair of the notions or whether there are more of them. (shrink)

Antecedent-strengthening, a trivially valid inference of classical logic of the form: P → Q ⊨ → Q, has a counterpart in everyday reasoning that often fails. A plausible solution to the problem involves assuming an implicit ceteris paribus qualifier that can be explicated as an additional conjunct in the antecedent of the premise. The qualifier can be explicated as ‘everything else relevant remains unchanged’ or alternatively as ‘nothing interferes’. The qualifier appears most prominently in the context of the discussion of (...) laws in the sciences, where these laws are often expressed with a CP qualifier. From an analysis of the qualifier’s role in the problem of antecedent-strengthening, we can learn more about CP qualifiers in general and in their application to the laws used in the sciences. (shrink)

A monist theory of explanation is one that seeks a common definition for all speech acts answering why-questions. One recent example is the counterfactual theory of explanation, which assumes that an ideal explanation can be characterized by the familiar Hempelian criteria for a scientific explanation plus a certain counterfactual that is supported by the laws mentioned in the explanans. I show that the CTE fails. My discussion leads to a critique of the CTE’s key concept of counterfactual dependence and to (...) the suggestion of an alternative: For an argument to be a scientific explanation, a certain necessary-condition claim must be true. For an answer to a why-question to be an explanation, it must express a certain necessary condition. (shrink)