Observation and conceptual interpretation constitute the two major ways through which human beings engage the world. The World Observed/The World Conceived presents an innovative analysis of the nature and role of observation and conceptualization. While these two actions are often treated as separate, Hans Radder shows that they are inherently interconnected-that materially realized observational processes are always conceptually interpreted and that the meaning of concepts depends on the way they structure observational processes and abstract from them. He examines the role of human action and conceptualization in realizing observational processes and develops a detailed theory of the relationship between observation, abstraction, and the meaning of concepts.The World Observed/The World Conceived will prove useful to many areas of scholarly study including ontology, epistemology, philosophy of language, philosophy of science, science studies, and cognitive science.