Mr. Wellman’s highly original contribution to the relatively new field of justification in ethics consists of characterizing the different ways in which ethical statements can be challenged and showing how each sort of challenge can be met by an appropriate response, enabling reasonable men to appropriately discuss or reflect on ethical issues. In developing his unique, systematic, methodology of ethics, Mr. Wellman has, first, rigorously reviewed and refuted the main arguments for the view of the nature of all reasoning as (...) deductive and, second, convincingly presented arguments for the existence of nondeductive evidences in ethics. Mr. Wellman’s broad definition of reasoning and his rejection of the identification of justification with reasoning reveals new dimensions of justification which will have wide implications in other areas of human speculation. (shrink)

In many actual arguments, the conclusion seems intuitively to follow from the premisses, even though we cannot show that it follows logically. The traditional approach to evaluating such arguments is to suppose that they have an unstated premiss whose explicit addition will produce an argument where the conclusion does follow logically. But there are good reasons for doubting that people so frequently leave the premisses of their arguments unstated. The inclination to suppose that they do stems from the belief that (...) the only way in which an argument's conclusion can follow definitely from its premisses is to follow logically. I argue that this belief is mistaken. I propose a revision of the current generic conception of logical consequence, and its variant specifications, to avoid the paradoxes of strict implication. The revised conception can then be naturally extended to include also what we might call 'enthymematic consequence'. This concept is a kind of consequence, whose properties merit investigation. (shrink)

Through a study of a sophisticated contemporary scientific experiment, it is shown how and why use of the term 'observation' in reference to that experiment departs from ordinary and philosophical usages which associate observation epistemically with perception. The role of "background information" is examined, and general conclusions are arrived at regarding the use of descriptive language in and in talking about science. These conclusions bring out the reasoning by which science builds on what it has learned, and, further, how that (...) process of building consists not only in adding to our substantive knowledge, but also in increasing our ability to learn about nature, by extending our ability to observe it in new ways. The argument of this paper is thus a step toward understanding how it is that all our knowledge of nature rests on observation. (shrink)

Mr. Wellman’s highly original contribution to the relatively new field of justification in ethics consists of characterizing the different ways in which ethical statements can be challenged and showing how each sort of challenge can be met by an appropriate response, enabling reasonable men to appropriately discuss or reflect on ethical issues. In developing his unique, systematic, methodology of ethics, Mr. Wellman has, first, rigorously reviewed and refuted the main arguments for the view of the nature of all reasoning as (...) deductive and, second, convincingly presented arguments for the existence of nondeductive evidences in ethics. Mr. Wellman’s broad definition of reasoning and his rejection of the identification of justification with reasoning reveals new dimensions of justification which will have wide implications in other areas of human speculation. (shrink)

This book provides a systematic analysis of many common argumentation schemes and a compendium of 96 schemes. The study of these schemes, or forms of argument that capture stereotypical patterns of human reasoning, is at the core of argumentation research. Surveying all aspects of argumentation schemes from the ground up, the book takes the reader from the elementary exposition in the first chapter to the latest state of the art in the research efforts to formalize and classify the schemes, outlined (...) in the last chapter. It provides a systematic and comprehensive account, with notation suitable for computational applications that increasingly make use of argumentation schemes. (shrink)

This book identifies 25 argumentation schemes for presumptive reasoning and matches a set of critical questions to each.

Relevance of premises to conclusion can be explicated through Toulmin’s notion of warrant, understood as an inference rule, albeit not necessarily formal. A normative notion of relevance requires the warrant to be reliable. To determine reliability, we propose a fourfold classification of warrants into a priori, empirical, institutional, and evaluative, with further subdivisions possible. This classification has its ancestry in classical rhetoric and recent epistemology. Distinctive to each type of warrant is the mode by which such connections are intuitively discovered (...) and the grounds on which we ultimately justify them. The classification of warrants is thus epistemic. We illustrate the difference by contrasting empirical physical with institutional intuition, and argue for the advantages of this approach over Toulmin’s conception of field dependence. (shrink)

The book was planned and written as a single, sustained argument. But earlier versions of a few parts of it have appeared separately. The object of this book is both to establish the existence of the paradoxes, and also to describe a non-Pascalian concept of probability in terms of which one can analyse the structure of forensic proof without giving rise to such typical signs of theoretical misfit. Neither the complementational principle for negation nor the multiplicative principle for conjunction applies (...) to the central core of any forensic proof in the Anglo-American legal system. There are four parts included in this book. Accordingly, these parts have been written in such a way that they may be read in different orders by different kinds of reader. (shrink)

This Element analyzes the various forms that design arguments for the existence of God can take, but the main focus is on two such arguments. The first concerns the complex adaptive features that organisms have. Creationists who advance this argument contend that evolution by natural selection cannot be the right explanation. The second design argument - the argument from fine-tuning - begins with the fact that life could not exist in our universe if the constants found in the laws of (...) physics had values that differed more than a little from their actual values. Since probability is the main analytical tool used, the book provides a primer on probability theory. (shrink)

This volume gives a theoretical account of the problem of analyzing and evaluating argumentative discourse. After placing argumentation in a communicative perspective, and then discussing the fallacies that occur when certain rules of communication are violated, the authors offer an alternative to both the linguistically-inspired descriptive and logically-inspired normative approaches to argumentation. The authors characterize argumentation as a complex speech act in a critical discussion aimed at resolving a difference of opinion. The various stages of a critical discussion are outlined, (...) and the communicative and interactional aspects of the speech acts performed in resolving a simple or complex dispute are discussed. After dealing with crucial aspects of analysis and linking the evaluation of argumentative discourse to the analysis, the authors identify the fallacies that can occur at various stages of discussion. Their general aim is to elucidate their own pragma- dialectical perspective on the analysis and evaluation of argumentative discourse, bringing together pragmatic insight concerning speech acts and dialectical insight concerning critical discussion. (shrink)