Frankfurt/M., Berlin, Bern, Bruxelles, New York, Oxford, Wien. This study provides an analysis of the perception of an object and of a human being; thereby, the author concentrates upon misperception, doubt and the consequent changes and modifications of perception insofar as the ‘different’ perceptions bear upon the ‘same’ object. It is argued that if one perception turns out to be a misperception and the perceptual sense ‘explodes’, then something ‘different’ is perceived. This phenomenology of perception includes the constitution of perceptual sense, the distinction between perceptual sense and perceptual judgment, elements of both constancy and change in the sense content of perception, the possibility of misperception and of doubt, the differentiation and identification of an object or a person, the structural difference of the perception of a human being, a body, a material object, and questions of intersubjectivity and of habits. Contents: Perceptual sense, misperception and changes of perception - The phenomenological method - Sensation and change - Object perception and intersubjectivity - Time and change - Habitus and change.