John D. Greenwood is Professor of Philosophy at the Graduate Center of the City University of New York, where he currently serves in the PhD Programs in Philosophy and Psychology. He is the author of four books, What Happened to the Social In American Social Psychology (Cambridge University Press, 2004), Realism, Identity and Emotion (1994), Relations and Representations (1991) and Explanation and Experiment in Social Psychological Science (1989), three edited volumes and over fifty articles. His main research interests are in the history and philosophy of social and psychological science.