The history of science is articulated by moments of discovery. Yet, these 'moments' are not simple or isolated events in science. Just as a scientific discovery illuminates our understanding of nature or of society, and reveals new connections among phenomena, so too does the history of scientific activity and the analysis of scientific reasoning illuminate the processes which give rise to moments of discovery and the complex network of consequences which follow upon such moments. Understanding discovery has not been, until recently, a major concern of modem philosophy of science. Whether the act of discoyery was regarded as mysterious and inexplicable, or obvious and in no need of explanation, modem philosophy of science in effect bracketed the question. It concentrated instead on the logic of scientific explanation or on the issues of validation or justification of scientific theories or laws. The recent revival of interest in the context of discovery, indeed in the acts of discovery, on the part of philosophers and historians of science, represents no one particular method'ological or philosophical orientation. It proceeds as much from an empiricist and analytical approach as from a sociological or historical one; from considerations of the logic of science as much as from the alogical or extralogical contexts of scientific tho'¢tt and practice. But, in general, this new interest focuses sharply on the actual historical and contem porary cases of scientific discovery, and on an examination of the act or moment of discovery in situ.

Inhalt
Understanding Scientific Discovery.- Scientific Judgment: Creativity and Discovery in Scientific Thought.- Discussion of Wartofsky's Paper.- The Rational Explanation of Historical Discoveries.- Theoretical and Methodological Innovation in the Copernican Era and Beyond: Social Factors.- The Legitimation of Scientific Belief: Theory Justification by Copernicus.- Wilhelm IV of Hesse-Kassel: Informal Commun-ication and the Aristocratic Context of Discovery.- The Clock Metaphor in the History of Psychology.- Biological Sciences From Darwin To Computer Diagnosis.- The Evolving Systems Approach to Creative Scientific Work: Charles Darwin's Early Thought.- Ought Philosophers Consider Scientific Discovery? A Darwinian Case-Study.- Theory Construction in Genetics.- Discovery in the Biomedical Sciences: Logic or Irrational Intuition?.- Comment on Schaffner.- Reply.- Reductionistic Research Strategies and their Biases in the Units of Selection Controversy.- Physics and Chemistry in the Twentieth Century.- The Discovery of a New Quantum Theory.- The Personal Character of the Discovery of Mechanisms in Cloud Physics.- The Structure of Discovery: Evolution of Structural Accounts of Chemical Bonding.- The Revolution in Geology: Continental Drift.- The Method of Multiple Working Hypotheses and the Development of Plate Tectonic Theory.- Hess's Development of his Seafloor Spreading Hypothesis.- Index of Names.- Index of Subjects.