Nicholas Rescher

On inference from inconsistent premisses

The main object of this paper is to provide the logical machinery needed for a viable basis for talking of the ‘consequences’, the ‘content’, or of ‘equivalences’ between inconsistent sets of premisses.With reference to its maximal consistent subsets (m.c.s.), two kinds of ‘consequences’ of a propositional set S are defined. A proposition P is a weak consequence (W-consequence) of S if it is a logical consequence of at least one m.c.s. of S, and P is an inevitable consequence (I-consequence) of S if it is a logical consequence of all the m.c.s. of S. The set of W-consequences of a set S it determines (up to logical equivalence) its m.c.s. (This enables us to define a normal form for every set such that any two sets having the same W-consequences have the same normal form.) The W-consequences and I-consequences will not do to define the ‘content’ of a set S. The first is too broad, may include propositions mutually inconsistent, the second is too narrow. A via media between these concepts is accordingly defined: P is a P-consequence of S, where P is some preference criterion yielding some of the m.c.s. of S as preferred to others, and P is a consequence of all of the P-preferred m.c.s. of S. The bulk of the paper is devoted to discussion of various preference criteria, and also surveys the application of this machinery in diverse contexts - for example, in connection with the processing of mutually inconsistent reports.

The Logic of Preference

The founder of the ‘logic of preference’ is the founding father of logic itself, Aristotle.

Introduction to value theory

A reprint of the popular 1969, Prentice-Hall edition, the principal innovation of this philosophical introduction to value theory is its focus upon values as they are dealt with in everyday life situations, and have sometimes been studied by sociologists and social psychologists, rather than upon value as has been standard in the philosophical tradition.

Cause and Counterfactual

It is shown how a causal ordering can be defined in a complete structure, and how it is equivalent to identifying the mechanisms of a system. Several techniques are shown that may be useful in actually accomplishing such identification. Finally, it is shown how this explication of causal ordering can be used to analyse causal counterfactual conditionals. First the counterfactual proposition at issue is articulated through the device of a belief-contravening supposition. Then the causal ordering is used to provide modal categories for the factual propositions, and the logical contradiction in the system is resolved by ordering the factual propositions according to these causal categories.

The Allocation of Exotic Medical Lifesaving Therapy

Technological progress has in recent years transformed the limits of the possible in medical therapy. However, the elevated state of sophistication of modern medical technology has brought the economists’ classic problem of scarcity in its wake as an unfortunate side product. The enormously sophisticated and complex equipment and the highly trained teams of experts requisite for its utilization are scarce resources in relation to potential demand. The administrators of the great medical institutions that preside over these scarce resources thus come to be faced increasingly with the awesome choice: Whose life to save?

ON PREDICTION AND EXPLANATION

ANALYSES in the philosophy of science frequently emphasise the logical similarities between prediction and explanation. It is said that prediction and explanation are identical from a logical standpoint, in that each is an instance of the use of reasoning in support of an hypothesis, and it is contended that the sole point of difference between them is that the hypothesis of a prediction concerns the future, while explanations concern the past.. We read, for example, that the difference between the two [i.e. prediction and explanation] is of a pragmatic character. If E [the conclusion of the explanatory schema] is given, i.e. if we know that the phenomenon described by E has occurred . . . we speak of an explanation of the phenomenon in question. If . . . E is derived prior to the occurrence of the phenomenon it describes, we speak of a prediction.

The Threefold Way

This essay is a study in the phenomenology of conception as distinguished from the more familiar phenomenology of perception. Its concern is with a particular resource of our cognitive strategy - one conceptual instrumentality for thinking about the nature of things. It investigates the idea that in contemplating the various aspects of the world’s arrangements, one can operate at three distinct “levels of consideration”: the levels of immediacy, proximity, and totality - of what is immediately at hand here and now, of what stands in the nearer offing at only a modest distance, and of what lies in the more distant and “visionary” reaches of an all-encompassing whole.

Peirce and the Economy of Research

The theory of the economics of research played a central role in the analysis of scientific method of Charles Sanders Peirce. The present paper describes Peirces project as he saw it and then puts its machinery to work in an analysis of current issues in the philosophy of science. The aim is to show that, even apart from their historical interest, Peirces ideas on this subject have a substantial systematic interest.

Reason and Reality

It is an unavoidable fact that substantial difficulties confront human inquiry in its project of gaining an appropriate under-standing of nature. In this connection, the present discussion will examine the ramifications and implications of four fundamental considerations regarding the situation of scientific theorizing: data underdetermine theories; theories underdetermine facts; reality transcends the descriptive resources of language (and symbolic representation in general); reality transcends the explanatory resources of science.

How serious a fallacy is inconsistency

Consistency is often pictured as an indispensable requisite for rationality. The paper argues that this is overly rigoristic. Inconsistency can be treated as a matter of isolable singularities rather than an all-destructive disaster. The paper, supports and illustrates a perspective on which consistency can be seen as a desideratum rather than a totaly non-negotiable demand. The argumentation of the paper casts consistency in the role of a cognitive ideal rather than a sine qua non condition of rational process.