Impossible Antecedents and Their Consequences: Some Thirteenth-Century Arabic Discussions

The principle that a necessarily false proposition implies any proposition, and that a necessarily true proposition is implied by any proposition, was apparently first propounded in twelfth century Latin logic, and came to be widely, though not universally, accepted in the fourteenth century. These principles seem never to have been accepted, or even seriously entertained, by Arabic logicians. In the present study, I explore some thirteenth century Arabic discussions of conditionals with impossible antecedents. The Persian-born scholar Afdal al-Dīn al-Khūnajī (d.1248) suggested the novel idea that two contradictory propositions may follow from the same impossible antecedent, and closely related to this point, he suggested that if an antecedent implies a consequent, then it will do so no matter how it is strengthened. These ideas led him, and those who followed him, to reject what has come to be known as ‘Aristotle's thesis’ that no proposition is implied by its own negation. Even these suggestions were widely resisted. Particularly influential were the counter-arguments of Naīr al-Dīn al-Tūī (d.1274).     

The Later Mohists and Logic

This article is a study of the Later Mohists' ‘Lesser Selection (Xiǎoq )’, which, more than any other early Chinese text, seems to engage in the study of logic. I focus on a procedure that the Mohists called móu . Arguments by móu are grounded in linguistic parallelism, implying perhaps that the Mohists were on the way to a formal analysis of argumentation. However, their main aim was to head off arguments by móu that targeted their own doctrines, and if their argument succeeds then it entails that linguistic parallelism can never ground a cogent argument. In a way, this committed them to the view that formal logic cannot work, but the fact that they did not pursue this line of investigation was by no means inevitable. One consequence of this study is that the Later Mohists conducted their logical work by studying the behaviour of terms and verb phrases, and did not identify the sentence as a significant linguistic unit. This tends to confirm Chad Hansen's generalisation that early Chinese philosophers did not posit sentences or other sentence-like entities such as propositions, beliefs, or laws. Focusing on subsentential expressions did not stop the Mohists from addressing genuinely logical issues, but it may help explain the fact that they never developed a conception of logical structure. This study includes the complete Chinese text of the ‘Lesser Selection’ and a translation in English.     

On the ethical analysis of value issues in public decision-making

Abstract

The nature, methodology, importance and implications of an ethical analysis of value issues pertaining to public decision-making is not evident. In this paper I would like to address these issues by posing the following questions:

• Why is it important to focus on values in any process of public decision-making?

• What is the nature of an ethical analysis of the value issues involved?

• What is the basis, if any, for ethical analysis that moves beyond relativism and subjectivity?

• What difference can such an ethical analysis make to public decision-making?

During the course of discussing these issues, the question “What is ethics?” will be addressed in passing, as well as the usual objections against ethics and the consideration of value issues in public decision-making, namely that

• values cannot be analysed and discussed objectively

• values and ethics are relative to people and cultures

• value and ethical questions cannot be settled in a rational manner

• ethics cannot provide answers

• arguments about value and ethical issues move in circles, taking us nowhere

• values and ethics are so intertwined with emotions and biases that one cannot take them seriously in any process of public decision-making.