Theo A. F. Kuipers

Inductive Analogy by Similarity and Proximity

Modern inductive logic, conceived as a theory of inductive probabilities, is intended to be a useful instrument for learning from experience not only in objective contexts, where there is some underlying objective probability process, but also in other, non-objective contexts. However, for designing inductive systems, objective applications form the primary challenge, for they provide the objective, but unknown, goal which has to be approached in a rational way on the basis of increasing experimental evidence. Hence, in the following we will presuppose an underlying probability process, except when otherwise stated.

Inference to the Best Theory, Rather than Inference to the Best Explanation — Kinds of Abduction and Induction

An interesting consequence of the theory of nomic truth approximation, as developed in my From Instrumentalism to Constructive Realism (Kuipers T, From instrumentalism to constructive realism. On some relations between confirmation, empirical progress, and truth approximation. Synthese Library 287. Kluwer Academic Publishers, Dordrecht, 2000), and enriched in this book, concerns so-called ‘inference to the best explanation’ (IBE). It can be argued that this popular rule among scientific realists can better be replaced by, various kinds of, ‘inference to the best theory’ (IBT). This chapter provides a survey of observational, theoretical, and referential kinds of IBT and discusses when and in what sense they may be seen as cases of ‘abduction’, that is, arguments for which an ‘abductive’ formulation and, hence, justification can be given in the minimal sense of Peirce.

How to Confirm the Conjunction of Disconfirmed Hypotheses

Could some evidence confirm a conjunction of two hypotheses more than it confirms either of the hypotheses separately? We show that it might, moreover under conditions that are the same for ten different measures of confirmation. Further, we demonstrate that it is even possible for the conjunction of two disconfirmed hypotheses to be confirmed by the same evidence.

Design research programs and the logic of their development

Design research programs attempt to bring together the properties of available materials and the demands derived from intended applications. The logic of problem states and state transitions in such programs, including assessment criteria and heuristic principles, is described in settheoretic terms, starting with a naive model comprising an intended profile and the operational profile of a prototype. In a first concretization the useful distinction between structural and functional properties is built into the model. In two further concretizations the inclusion of potential applications is motivated and described for the case of drug research as well as the inclusion of potential realizations for the case of complex products. Next, another line of concretization of the naive model, the incorporation of potentially relevant properties, is sketched. Then the partial analogy between “product-” and “truth-approximation” is indicated. We conclude with some remarks about the usefulness of our models for products reaching the market in comparison to the the so-called social construction of technology approach.

An erotetic approach to explanation by specification

In earlier publications of the first author it was shown that intentional explanation of actions, functional explanation of biological traits and causal explanation of abnormal events share a common structure. They are called explanation by specification (of a goal, a biological function, an abnormal causal factor, respectively) as opposed to explanation by subsumption under a law. Explanation by specification is guided by a schematic train of thought, of which the argumentative steps not concerning questions were already shown to be logically valid (elementary) arguments.Independently, the second author developed a new, inferential approach to erotetic logic, the logic of questions. In this approach arguments resulting in questions, with declarative sentences and/or other questions as premises, are analyzed, and validity of such arguments is defined.In the present paper it is shown that all four kinds of erotetic argumentative steps occurring in the train of thought of explanation by specification are valid arguments in the sense of inferential erotetic logic. Hence, in view of the fact that the other argumentative steps were already shown to be valid, it may be concluded that the logical structure of explanation by specification can be as well-established as that of explanation by nomological subsumption. Moreover, explanation by specification provides some illustrations of the applicability of erotetic logic in everyday life and some empirical sciences.

Laws, theories and research programs

Publisher Summary This chapter discusses laws, theories, and research programs. In the empirical sciences, the informal distinction between observational laws and proper theories plays a crucial role. Observational laws are supposed to describe observationally—usually experimentally—established regularities. Different names for roughly the same concept are: empirical, experimental or phenomenological laws, reproducible effects, inductive generalizations, and general facts. Proper theories or systems of theoretical laws (together with definitions and other conventions), on the other hand, are supposed to explain such laws and to predict new ones, by postulating underlying mechanisms. The law-distinction forms a crucial construction principle for the hierarchy of knowledge. Therefore, it is an important heuristic factor in the dynamics of knowledge development. However, it has occasioned philosophers of science much brain-racking to explicate the law-distinction in a defensible way. Without doubt, the distinction is strongly related to the distinction between observational (or empirical or experimental) and theoretical terms. Whereas proper theories introduce theoretical terms, observational laws do not.

Dovetailing Belief Base Revision with (Basic) Truth Approximation

Recently, Gustavo Cevolani, Vincenzo Crupi and Roberto Festa have shown that their account of verisimilitude of ‘conjunctive theories’ of a finite propositional language can be nicely linked to a variant of AGM belief set revision, viz. belief base revision, in the sense that the latter kind of revision is functional for truth approximation according to the conjunctive account (Cevolani et al., Erkenntnis 75(2):183–222, 2011). In the present paper I offer a generalization of these ideas to the case of approaching any divide of a (finite or infinite) universe, allowing several interpretations, besides true (false) atomic propositions, notably nomic states (not) in equilibrium, nomic (im)possibilities, (non-)instantiated ‘Q-predicates’ of a monadic language. It shows how and why approximation of ‘the true boundary’ takes place by belief base revision guided by evidence.

THE THREEFOLD EVALUATION OF THEORIES: A SYNOPSIS OF FROM INSTRUMENTALISM TO CONSTRUCTIVE REALISM. ON SOME RELATIONS BETWEEN CONFIRMATION, EMPIRICAL PROGRESS, AND TRUTH APPROXIMATION (2000)

Surprisingly enough, modified versions of the confirmation theory of Carnap and Hempel and the truth approximation theory of Popper turn out to be smoothly synthesizable. The glue between confirmation and truth approximation appears to be the instrumentalist methodology, rather than the falsificationist one. By evaluating theories separately and comparatively in terms of their successes and problems (hence even if they are already falsified), the instrumentalist methodology provides - both in theory and in practice - the straight route for short-term empirical progress in science in the spirit of Laudan. However, it is argued that such progress is also functional for all kinds of truth approximation: observational, referential, and theoretical. This sheds new light on the long-term dynamic of science and hence on the relation between the main epistemological positions, viz., instrumentalism (Toulmin, Laudan), constructive empiricism (van Fraassen), referential realism (Hacking and Cartwright), and theory realism of a nonessentialist nature (Popper), here called constructive realism. In From Instrumentalism to Constructive Realism (2000) the above story is presented in great detail. The present synopsis highlights the main ways of theory evaluation presented in that book, viz. evaluation in terms of confirmation (or falsification), empirical progress and truth approximation.

Quantitative Nomic Truth Approximation by Revising Models and Postulates

In my paper, “Models, postulates, and generalized nomic truth approximation” (Kuipers 2016), I have presented the ‘basic’ version of generalized nomic truth approximation, starting from ‘two-sided’ theories. Its main claim is that nomic truth approximation can perfectly be achieved by combining two prima facie opposing views on theories: (1) the traditional (Popperian) view: theories are (models of) postulates that exclude certain possibilities from being realizable, enabling explanation and prediction and (2) the model view: theories are sets of models that claim to (approximately) represent certain realizable possibilities. Nomic truth approximation, i.e. increasing truth-content and decreasing falsity-content, becomes in this way revising theories by revising their models and/or their postulates in the face of increasing evidence.

General Introduction: Epistemological Positions

We will start by sketching in a systematic order the most important epistemological positions in the instrumentalism-realism debate, viz., instrumentalism, constructive empiricism, referential realism and theory realism. They will be ordered according to their answers to a number of leading questions, where every next question presupposes an affirmative answer to the foregoing one. The survey is restricted to the investigation of the natural world and hence to the natural sciences. It should be stressed that several complications arise if one wants to take the social and cultural world into account. However, the present survey may well function as a point of departure for discussing epistemological positions in the social sciences and the humanities.