This book is the fruit of a study group on perception and action that worked at the Center for Interdisciplinary Research (ZiP) of the University of Bielefeld, FRG in the academic year 1984-1985. We express our gratitude to the ZiF for hosting the group and for providing fmancial and organizational support for its scientific activities, including a meeting of the authors of the present volume that took place at the ZiF in July 1986. This is/ the study group's last common product, and it took considerable time to give the book its fmal shape. Most of the editing was done while one of us (0. N.) was a Fellow at the Netherlands Institute for Advanced Study in the Humanities and Social Sciences (NlAS) during the academic year 1987-1988. Thanks are due to NIAS for its generous support. We also thank all our friends and colleagues who contributed to the book.

"Kognitionspsychologie" ist ein neuer, kaum zwei Jahrzehnte alter Name fur eme freilich alte Sache. Die Psychologie der Erkenntnisfunktionen hat schon in der philosophischen Vorgeschichte der Psychologie ein abgesondertes - wohl auch manchmal ein als absonderlich wahrgenommenes - Dasein neben den anderen, leichter zuganglichen Sparten unseres Fachs gefuhrt. David Humes 1742 erschienene "Inquiry concerning human understanding" beginnt mit einer hubschen Kenn- zeichnung dieser Eigenart: "Moral philosophy, or the science of human nature, may be treated after two different manners; each of which has its peculiar merit, and may contribute to the entertainment, instruction, and reformation of mankind. The one considers man chiefly as born for action; and as influenced in his measures by taste and sentiment; pursuing one object, and avoiding another, according to the value which these objects seem to possess . . . ". Die Vertreter dieser Richtung werden beschrieben als "borrowing all helps from poetry and eloquence, and treating their subject in an easy and obvious manner, and such as is best fitted to please the imagination, and engage the affections". Dem stehen diejenigen gegeniiber, "(who) . . . with a narrow scrutiny examine (human nature) . . ., in order to find those principles, which regulate our understanding, excite our sentiments, and make us approve or blame any particular object, action, or behaviour . . . While they attempt this arduous task, they are deterred by no difficul- ties . . .