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)

1 Knowledge and Justification This book is an investigation of one central problem which arises in the attempt to give a philosophical account of empirical ...

How should we evaluate an argument in which two witnesses independently testify to some claim? In fact what would happen is that the testimony of the second witness would be taken to corroborate that of the first to some extent, thereby boosting up the plausibility of the first argument from testimony. But does that commit the fallacy of double counting, because the second testimony is already taken as independent evidence supporting the claim? Perhaps the corroboration effect should be considered illogical, (...) since each premise should be seen as representing a separate reason in a convergent argument for accepting the claim as plausible. In this paper, we tackle the problem using argumentation schemes and argument diagramming. We examine a number of examples, and come up with two hypotheses that offer methods of analyzing and evaluating this kind of evidence. (shrink)

In previous work I argued against (i) the likelihood of finding a theoretically sound foundation for the linked/convergent distinction and (ii) the utility of the distinction even if a sound theoretical basis could be found. Here I subject Douglas Walton’s comprehensive discussion of the linked/convergent distinction found in Argument Structure: A Pragmatic Theory to careful scrutiny and argue that at best Walton’s theory remains incomplete and that attempts to fill out the details will run afoul of at least one of (...) the problems adduced above—i.e., result in either a theoretically unsound distinction or a theoretically sound, but unnecessary distinction. (shrink)

This paper begins a working through of Blair’s (2001) theoretical agenda concerning argumentation schemes and their attendant critical questions, in which we propose a number of solutions to some outstanding theoretical issues. We consider the classification of schemes, their ultimate nature, their role in argument reconstruction, their foundation as normative categories of argument, and the evaluative role of critical questions.We demonstrate the role of schemes in argument reconstruction, and defend a normative account of their nature against specific criticisms due to (...) Pinto (2001). Concerning critical questions, we propose an account on which they are founded in the R.S.A. cogency standard, and develop an account of the relationship between critical questions and burden of proof. Our ultimate aim is to initiate a reconciliation between dialectical and informal logic approaches to the schemes. (shrink)

A detailed treatment regarding the diverse properties and uses of evidence and the judgmental tasks they entail. Examines various processes by which evidence may be developed or discovered. Considers the construction of arguments made in defense of the relevance and credibility of individual items and masses of evidence as well as the task of assessing the inferential force of evidence. Includes over 100 numerical examples to illustrate the workings of diverse probabilistic expressions for the inferential force of evidence and the (...) subtleties they reveal. (shrink)

Even with Kientpointer's and Walton's valuable work, we do not yet have a complete theory of argument schemes. A complete theory of argument schemes should contain at least the following: its theoretical motivation, the denotation of "argument" or "ar gumentation" used in the theory, an analysis of the concept of an argument scheme, a theory of classification of argument schemes, a solution to the problem of identifying which scheme is correct, and an account of the grounds of the normativity or (...) normat ive argument schemes. The paper will supply these elements, worked out as fully as space permits. (shrink)