A computational theory of induction must be able to identify the projectible predicates, that is to distinguish between which predicates can be used in inductive inferences and which cannot. The problems of projectibility are introduced by reviewing some of the stumbling blocks for the theory of induction that was developed by the logical empiricists. My diagnosis of these problems is that the traditional theory of induction, which started from a given (observational) language in relation to which all inductive rules are (...) formulated, does not go deep enough in representing the kind of information used in inductive inferences. As an interlude, I argue that the problem of induction, like so many other problems within AI, is a problem of knowledge representation. To the extent that AI-systems are based on linguistic representations of knowledge, these systems will face basically the same problems as did the logical empiricists over induction. In a more constructive mode, I then outline a non-linguistic knowledge representation based on conceptual spaces. The fundamental units of these spaces are "quality dimensions". In relation to such a representation it is possible to define "natural" properties which can be used for inductive projections. I argue that this approach evades most of the traditional problems. (shrink)

This book argues for the need to put into practice a profound and comprehensive intellectual revolution, affecting to a greater or lesser extent all branches of scientific and technological research, scholarship and education. This intellectual revolution differs, however, from the now familiar kind of scientific revolution described by Kuhn. It does not primarily involve a radical change in what we take to be knowledge about some aspect of the world, a change of paradigm. Rather it involves a radical change in (...) the fundamental, overall intellectual aims and methods of inquiry. At present inquiry is devoted to the enhancement of knowledge. This needs to be transformed into a kind of rational inquiry having as its basic aim to enhance personal and social wisdom. This new kind of inquiry gives intellectual priority to the personal and social problems we encounter in our lives as we strive to realize what is desirable and of value – problems of knowledge and technology being intellectually subordinate and secondary. For this new kind of inquiry, it is what we do and what we are that ultimately matters: our knowledge is but an aspect of our life and being. (shrink)

Nelson Goodman has constructed two theories of simplicity: one of predicates; one of hypotheses. I offer a simpler theory by generalization and abstraction from his. Generalization comes by dropping special conditions Goodman imposes on which unexcluded extensions count as complicating and which excluded extensions count as simplifying. Abstraction is achieved by counting only nonisomorphic models and subinterpretations. The new theory takes into account all the hypotheses of a theory in assessing its complexity, whether they were projected prior to, or result (...) from, projection of a given hypothesis. It assigns simplicity post-projection priority over simplicity pre-projection. It better orders compound conditionals than does the theory of simplicity of hypotheses, and it does not inherit an anomaly of the theory of simplicity of predicates — its failure to order the ordering relations. Drop Goodman's special conditions, and the problems fall away with them. (shrink)

Theoretical simplicity is difficult to characterize, and evidently can depend upon a number of distinct factors. One such desirable characteristic is that the laws of a theory have relatively few "counterinstances" whose accommodation requires the invocation of a ceteris paribus condition and ancillary explanation. It is argued that, when one theory is reduced to another, such that the laws of the second govern the behavior of the parts of the entities in the domain of the first, there is a characteristic (...) gain in simplicity of the sort mentioned: while I see no way of quantitatively measuring the "amount" of defeasibility of the laws of a theory, microreduction can be shown to decrease that "amount.". (shrink)

Occam’s razor refers to the idea that among competing explanations the simplest should be preferred. This principle has been understood and defended in different ways. Some systems biologists argue that traditional molecular biology is misguided because it relies on an unjustified application of Occam’s razor. I analyze which version of the principle is relevant in this context and ask whether the allegation stands up to scrutiny by looking at actual research. I defend the traditional approach by arguing that its use (...) of Occam’s razor is innocuous and by showing that systems biology heavily relies on considerations of simplicity as well. (shrink)

There seems a potential tension between Hume's naturalistic project and his normative ambitions. Hume adopts what I call a methodological naturalism: that is, the methodology of providing explanations for various phenomena based on natural properties and causes. This methodology takes the form of introducing ‘the experimental method of reasoning into moral subjects’, as stated in the subtitle of the Treatise; this ‘experimental method’ seems a paradigmatically descriptive one, and it remains unclear how Hume derives genuinely normative prescriptions from this methodology. (...) In resolving this problem, I will argue that Hume's naturalistic methodology – that is, his ‘experimental philosophy’, or what has come to be known as his experimental method – consists of the systematization of phenomena pertaining to human nature. In applying his experimental method to normative subjects, Hume systematizes our normative judgements, deriving general principles of normative justification; he then reflexivel... (shrink)

This volume is a collection of some of the most important philosophical papers by Peter Gärdenfors. Spanning a period of more than 20 years of his research, they cover a wide ground of topics, from early works on decision theory, belief revision and nonmonotonic logic to more recent work on conceptual spaces, inductive reasoning, semantics and the evolutions of thinking. Many of the papers have only been published in places that are difficult to access. The common theme of all the (...) papers is the dynamics of thought. Several of the papers have become minor classics and the volume bears witness of the wide scope of Gärdenfors’ research and of his crisp and often witty style of writing. The volume will be of interest to researchers in philosophy and other cognitive sciences. (shrink)

Recently Samuel Richmond, generalizing Nelson Goodman, has proposed a measure of the simplicity of a theory that takes into account not only the polymorphicity of its models but also their internal homogeneity. By this measure a theory is simple if small subsets of its models exhibit only a few distinct (i.e., non-isomorphic) structures. Richmond shows that his measure, unlike that given by Goodman's theory of simplicity of predicates, orders the order relations in an intuitively satisfactory manner. In this note I (...) formalize his presentation and suggest an improvement designed to overcome certain technical difficulties. (shrink)

The main theme is that theorizing serves empirical prediction. This is used as the core of a counter to contemporary anti-realist arguments. Different versions of the thesis that data underdetermines theory are identified and it is shown that none which are acceptable differentiates between theory selection and prediction. Criteria sufficient for the former are included amongst those necessary for the latter; and obviously go beyond mere compatibility with data.Special attention is given to causal process theories. It is argued that the (...) only empirically equivalent alternatives which can be constructed to any theory of this kind must be parasitic on that theory; so a choice for the original theory can not be avoided. Once this is established, a positive case for taking a realist position can be developed. (shrink)

Chomsky has constructed an empirical theory about syntactic universals of natural language by defining a class of 'possible languages' which includes all natural languages (inter alia) as members, and claiming that all natural languages fall .within a specified proper subset of that class. I extend Chomsky's work to produce an empirical theory about natural4anguage semantic universals by showing that the semantic description of a language will incorporate a logical calculus, by defining a relatively wide class of 'possible calculi', and by (...) specifying a proper subset of that class which, I hypothesize, includes the calculi needed for the semantic description of any natural language. I argue that the special status, with respect to natural languages, of this particular type of logical calculus is an empirical finding which does not follow from any independently-known principles, and I conclude that the question why the laws of human thought have the structure they do is a biological rather than a logical question. (shrink)

Paleobiologists often provide simple narratives to explain complex, contingent episodes. These narratives are sometimes ‘one-shot hypotheses’ which are treated as being mutually exclusive with other possible explanations of the target episode, and are thus extended to accommodate as much about the episode as possible. I argue that a provisional preference for such hypotheses provides two kinds of productive scaffolding. First, they generate ‘hypothetical difference-makers’: one-shot hypotheses highlight and isolate empirically tractable dependencies between variables. Second, investigations of hypothetical difference-makers provision explanatory (...) resources, the ‘raw materials’ for constructing more complex—and likely more adequate—explanations. Provisional preferences for simple, one-shot hypotheses in historical science, then, is defeasibly justified on indirect—strategic—grounds. My argument is made in reference to recent developments regarding the K–Pg extinction. (shrink)