1. Introduction.- 2. The Discovery of the Masses.- A New Human Dimension: The Crowd.- How a Science Discovers Its Facts.- The Riddle of Crowd Formation.- A Science of the Irrational.- Crowds are the Unconscious.- Natural Crowds and Artificial Crowds.- 3. Models of Suggestive Influence and the Disqualification of the Social Crowd.- The Political and Intellectual Climate of Fin-de-Siècle Paris.- Disqualification and Revolution: The Perspective of the Crowd Psychologies.- From Medical to Psychiatric Praxis-From Animal Magnetism to Suggestive Influence.- Hypnosis Versus Suggestion-The Nancy/Salpêtrière Debate.- Binet at the Salpêtrière-Dogmatic Experimentation.- The Pervasiveness of the Hypnosis/Suggestion Model at the End of the 19th Century.- From Theories of Magnetism to Political Ideology.- From Suggestive Influence to Crowd Psychology.- Binet at the Crossroads of the Social Psychology of Interpersonal Influence.- Conclusion.- 4. Freud and Massenpsychologie.- 5. Mass Psychology, Social Psychology, and the Politics of Mussolini.- Brief Presentations.- Mussolini and the Three Authors.- Le Bon, Orano, and Sorel and the Sociopsychological Study of Mussolini's Rise and Fall.- 6. The Social Psychology of William McDougall.- McDougall's Two Volume Social Psychology.- Reaction to McDougall's Social Psychology.- Postscript.- 7. The Individualization of the Social and the Desocialization of the Individual: Floyd H. Allport's Contribution to Social Psychology.- Social Psychology as Individual Psychology.- The Individual Psychology of Crowds and Groups.- The Individualization of Social Psychology: An Evaluation in Retrospect.- 8. Conceptions of Crowds and Crowding.- Everyday Experiences of Crowds and Crowding.- The Unrelatedness of Crowds and Crowding in Scientific Research and Discourse.- Crowd Psychology.- Crowding Phenomena and Research on Crowding.- The Janus-Faced Problem of Crowd and Crowding.- 9. Collective Behavior from the 17th to the 20th Century: Change of Phenomena, Change of Perception or No Change at All? Some Preliminary Reflections.- A Paradigm Change in Perception.- From "Revolts" to "Revolution": The Continental World.- The Natural Law of Mass Action: The Anglo-Saxon World.- The Rebellious Subjects: Germany.- A Paradigm Change in Interpretation of Motivation: From Passions to Interests (17th-18th Centuries).- A Paradigm Change in Perceiving the "Laboring Poor" in England: From Low to High Wages as Incentive for Work.- The Laborer as "Working Animal" and the "Unpredictable Natural Forces" of Working Class Action: The German Kaiserreich.- Class Interests and Perception.- 10. Masses-From an Idealistic to a Materialistic Point of View? Aspects of Marxian Theory of the Class.- Social Movement as a Dialectical Process.- The Conflict Between Bauer and Marx.- Mass and Class.- 11. Mass, Mobilization, and the State.- Individual Action and Collective Movement.- 12. The Social Organization of Early Human Groups.- 13. Crowd Mind and Behavior: Afterthoughts.- The Historical Versus Scientific Approach to Mass Phenomena.- Top-Down Versus Bottom-Up Conceptions of Mass Phenomena.- The Rationalist Versus Irrationalist Explanations of Crowd Phenomena.- Author Index.

Serge Moscovici It has recently become commonplace to say that science and its history are one. Nonetheless, in practice things have not changed much. We still behave as ifthe two were not really connected. Or else as if it were hard, not to say impossible, to link them in a single enquiry. In such circumstances the group we constitute and which has undertaken the task of studying the history of social psychology while refor­ mulating its theories represents an experiment. Whether the experiment succeeds or fails, the three aims we have set ourselves are precise: First, we wish to bring up to date the relation between certain topics of psycho­ logical research and their historical context. Second, we will include within the discussion itself and consider critically some authors and works that have become our classics due to their undiminished signifi­ cance and heuristic power. But, in this respect, we also consider that we should depart from the attitude of the physical sciences shared by so many psychologists that past acquisitions have nothing to offer as a basis for research. Only those scholars who have said their say and completed their task indulge in such medita­ tions; therefore work undertaken in this field is unimportant and even illicit. We, on the other hand, are convinced that social psychology is, after all, a social science and that a study based on orthodox theories is still eminently significant.