In Practical Ethics Peter Singer argues for an �obligation to assist�: First premise: If we can prevent something bad without sacrificing anything of comparable significance, we ought to do it. Second premise: Absolute poverty is bad. Third premise: There is some absolute poverty we can prevent without sacrificing anything of comparable moral significance. Conclusion: We ought to prevent some absolute poverty. This paper is dedicated to a criticism of four readings of the first premise and an undesirable link the first (...) premise has with the third. The paper ends by offering a alternative formulation of an �obligation to assist,� which suffers from none of these problems. (shrink)
Three views on definite descriptions are summarized and discussed, including that of P. F. Strawson in which reference failure results in lack of truth value. When reference failure is allowed, a problem arises concerning Universal Instantiation. Van Fraassen solves the problem by the use of supervaluations, preserving as well such theorems as a=a, and Fa Fa, even when the term a fails to refer. In the present paper a form of relevant, quasi-analytic implication is set out which allows reference failure (...) to infect even a=a and Fa Fa with lack of truth-value. Reference failure causes lack of truth-value in a subwff to spread throughout any wff built up by the classical connectives. As a result none of the classical firstorder axiom schemes remain as axiom schemes in the system presented. (shrink)
<span class='Hi'></span> In <span class='Hi'></span><span class='Hi'></span> a semantics for implication is offered that makes use of stories <span class='Hi'></span>— sets of sentences assembled under various constraints.<span class='Hi'></span> Sentences are evaluated at an actual world and in each member of a set of stories.<span class='Hi'></span> A sentence B is true in a story s just when B s.<span class='Hi'></span> A implies B iff for all stories and the actual world,<span class='Hi'></span> whenever A is true,<span class='Hi'></span> B is true.<span class='Hi'></span> In this (...) article the first-order language of <span class='Hi'></span><span class='Hi'></span> is extended by the addition of the operator the story <span class='Hi'></span>..<span class='Hi'></span>. says that <span class='Hi'></span>..<span class='Hi'></span>.,<span class='Hi'></span> as in The story Flashman among the Redskins says that Flashman met Sitting Bull.<span class='Hi'></span> The resulting language is shown to be sound and complete. (shrink)
In this paper a system, RPF, of second-order relevance logic with S5 necessity is presented which contains a defined, notion of identity for propositions. A complete semantics is provided. It is shown that RPF allows for more than one necessary proposition. RPF contains primitive syntactic counterparts of the following semantic notions: (1) the reflexive, symmetrical, transitive binary alternativeness relation for S5 necessity, (2) the ternary Routley-Meyer alternativeness relation for implication, and (3) the Routley-Meyer notion of a prime intensional theory, as (...) well as defined syntactic counterparts, of the semantic notions of a possible world and the Routley-Meyer * operator. (shrink)
By the standards presented in the Introduction, CMFC2 is deficient on at least one ontological ground: ‘∀’ is a syncategorematic expression and so CMFC2 is not an ideal language. To some there may be an additional difficulty: any two wffs provably equivalent in the classical sense are provably identical. We hope in sequel to present systems free of these difficulties, free either of one or the other, or perhaps both.This work was done with the aid of Canada Council Grant S74-0551-S1.