Reprint of the original, first published in 1869.

A compact, coherent introduction to the study of rational belief, this text provides points of entry to such areas of philosophy as theory of knowledge, methodology of science, and philosophy of language. The book is accessible to all undergraduates and presupposes no philosophical training.

Summary With the help of psychological and biological concepts it is possible todescribe adequately a fundamental class of inductive inferences that are intuitively correct. Moreover, by relying on evolutionary theories it is possible tojustify them, because they reflect innate, hence useful, capacities. These inferences, however, refer to the past, i.e. the inferred generalization is of the form All Awere B . The reason is that evolutionary theories only claim that innate capacitieshad survival value. With respect to inductive inferences about the (...) future the situation is different. In particular, they are affected by the Goodman paradox. In the article, a method is proposed which enables us to describe adequately a basic class of inductive inferences about the future which are intuitively correct. These inferences can also be justified, but their justification requires a very specific assumption. The conclusions arrived at in the article can be viewed as a satisfactory solution to the Goodman paradox. (shrink)

Conceptual change and its connection to the development of new seien tific theories has reeently beeome an intensively discussed topic in philo sophieal literature. Even if the inductive aspects related to conceptual change have already been discussed to some extent, there has so far existed no systematic treatment of inductive change due to conceptual enrichment. This is what we attempt to accomplish in this work, al though most of our technical results are restricted to the framework of monadic languages. We (...) extend Hintikka's system of inductive logic to apply to situations in which new concepts are introduced to the original language. By interpreting them as theoretica1 concepts, it is possible to discuss a number of currently debated philosophical and methodological problems which have previously escaped systematic and exact treatment. For instance, the role which seientific theories employing theoretical con cepts may play within inductive inference can be studied within this framework. From the viewpoint of seientific realism, sueh a study gives outlines for a theory of what we call hypothetico-induetive inference. Some parts of this work which are based on Hintikka's system of in ductive logic are fairly technical. However, no previous knowledge of this system is required, but, in general, acquaintance with the basic ideas of elementary logic and probability theory is suffieient. This work is part of a project, originated by Professors Jaakko Hintikka and Raimo Tuomela, concerning the role of theoretical concepts in science. (shrink)

According to our intuitions, certain generalizations are better confirmed by positive instances than others. In order to characterize the difference between these generalizations, I have proposed in [3] to investigate the generalizing behavior of living beings. Such an investigation makes it possible to classify into different categories the generalizations that are intuitively confirmed by their positive instances and those that are not intuitively confirmed by such instances. One important aspect of my treatment, however, has been shown to be unsatisfactory: sentences (...) that are logically equivalent may belong to different categories. In this paper, I shall first give a short summary of the relevant parts of my previous paper, and then I shall try to improve it in order to avoid the undesirable result. (shrink)