The roots of this work lie in my earlier book, Scientific Progress, which first appeared in 1981. One of its topics, the distinction - tween scientific laws and theories, is there treated with reference to the same distinction as drawn by N. R. Campbell in his Physics: The Elements. Shortly after completing Scientific Progress, I read Rom Harré¿s The Principles of Scientific Thinking, in which the concept of theory is even more clearly delineated than in Campbell, being directly connected to the notion of a model ¿ as it was in my book. In subsequent considerations regarding science, Harré¿s work thus - came my main source of inspiration with regard to theories, while Campbell¿s remained my main source with respect to empirical laws. Around the same time I also read William Whewell¿s Philosophy of the Inductive Sciences. In this work, Whewell depicts principles as playing a central role in the formation of science, and conceives of them in much the same way as Kant conceives of fundamental synthetic a priori judgements. The idea that science should have principles as a basic element immediately made sense to me, and from that time I have thought of science in terms of laws, theories and principles.

Empiricism Vs. Realism - The Perennial Debate In The Philosophy Of Science.- Fundamental And Refined Principles: The Core Of Modern Science.- Empirical Laws: The Supervention Of Experience.- Scientific Theories: Closing The Circle.- The Principle-Theory-Law Model Of Scientific Explanation.- The Social Sciences: A Consideration Of Economics.- Natural Kinds.- Probability And Confirmation.- Empiricism Vs. Realism Revisited.- Modern Science And The Future.