Science is the art of answering new questions, but more and more often is facing problems which are the product of its own success. First among these is the problem posed by the relationship between scientific research and economic growth, generated by the changing equilibrium among the developed countries and the growing gap between the North and South of the planet, by a new conception of health and the quality of life and by the questions that technological progress poses for the future of human race and the environment. Scientific progress has always deeply modified social organisation and individual liife style and attitude, often indipendently from a public awareness of these transformations. Today, the relationship between science and economics is stronger than ever, and the pace of discoveries and their application is more and more rapid. Communicating to the public the potential and the limits of research is therefore indispensable to create a good relationship between science and society, between decision-makers and the citizen. Ten Nobel Laureates are invited to turn their attention to the major issues that have emerged from the redefinition of our conceptions of humanity, nature and society in the wake of scientific progress. Their lectures are divided into five sessions.

Exploring Complexity Tuesday 7 December 1993 One of the characteristic features of science in the last decades is the discovery of complexity. At all levels from cosmology to human sciences we observe fluctuations and instability. A short description of the role of complexity in different fields of science will be presented. It will be pointed out that the study of complexity leads to a revision of the concept of laws of nature. The classical view was that the laws of nature were time reversible and deterministic. No distinction was made between past and future. We come now to a formulation of the laws of nature which includes probability and irreversibility. The new laws of nature tell us what may happen and not what will happen. The study of the laws of complexity is of special importance for problems connected to the biosphere. They also introduce important elements to bridge the relation between the so-called two cultures. We begin now to overcome the classical Cartesian dualism which describes the world as an automaton. The paradigm for the coming century may well be the study of the circumstances which determine the evolution of a self-organizing universe. The resulting essay has been translated into Italian and published in the book Scienza, economia, etica per il prossimo secolo. Dieci Nobel per il futuro. (Marsilio, Venezia 1994).