The previous chapters reviewed several aspects of the many problems faced by psychologists when they attempt to understand form recognition. Proposed methods for internally representing stimulus images have been considered; a sample of the psychophysical literature that is relevant to the problem has been reviewed; and the main alternative theories of the process have been explored. Throughout this discussion, I have emphasized how the technical, empirical, theoretical, and even conceptual topics that were raised speak to the problems faced when we try to understand how the powerful recognition capabilities of the human visual system are carried out.