Of two false theories, One can be, Intuitively, Closer to the truth than the other. The purpose of the article is to propose a rigorous explication of this intuitive notion.

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)

to that goal, and it is hoped that it will incorporate further works dealing in an exact way with interesting philosophical issues. Zurich, April 1973 Mario Bunge Preface In this book I have investigated the logical and methodological role of the much debated theoretical concepts in scientific theories. The philosophical viewpoint underlying my argumentation is critical scientific realism. My method of exposition has been to express ideas first in general terms and then to develop and elaborate them within a specific (...) formal framework. It is assumed in the book that the reader has a relatively good knowledge of the basic techniques and results of modern symbolic logic, including model theory. Examples from actual science are mostly from the social sciences. I have deliberately omitted a treatment of a number of characteristic features which are particular to theoretical concepts in the more developed sciences, such as modern physics. This book owes very much to Professor Jaakko Hintikka, to whom I wish to express my deep gratitude. Especially at the begin ning of this project in 1968/69 when I was doing research for my doctoral degree at Stanford University I worked with him closely. (shrink)