This is the second of two volumes containing papers submitted by the invited speakers to the 11th international Congress of Logic, Methodology and Philosophy of Science, held in Cracow in 1999, under the auspices of the International Union of History and Philosophy of Science, Division of Logic, Methodology and Philosophy of Science. The invited speakers are the leading researchers and accordingly the book presents the current state of the intellectual discourse in the respective fields. The papers delivered at the congress were divided into 17 sections. Thus the structure of the volume corresponds to the very schedule of the congress. Volume two contains the closing lecture by John Maynard Smith and the invited papers on topics such as: Philosophy of the Biological Sciences, Philosophy of Cognitive Science and Artificial Intelligence, Philosophy of Linguistics, Philosophy of the Social Sciences, Ethics of Science and Technology, History of Logic, Methodology, and Philosophy of Science, Philosophical Questions Raised by the History and Sociology of Science. It also contains invited papers in two other symposia: "A Hundred Years of the Philosophy of Science and Cognitive Science Meets Philosophy of Science", as well as a special lecture delivered by Stanislaw Lem. We hope that the book could be of interest to philosophers, biologists, linguists, cognitive scientists, social scientists, sociologists, as well as historians and philosophers of science.