Two human mental activities, "imagination" and "reasoning," are ordinarily conceived as contrastive. It is often said that reasoning is a constitutive factor of the social sciences, but not a necessary condition for arts, and imagination is a constitutive factor of arts, but not a necessary condition for the social sciences. The objects, events, and occurrences perceived and recognized are, however, "thought objects," and "imagination of hypothetical sense presentations" is indispensable for completing them. Imagination is a constitutive factor not only for arts but also for the social sciences. Sociology could not recognize society without the "sociological imagination."This essay aims to explore the "sociological imagination" in comparison to the so-called "artistic imagination," basing on Alfred Schutz's ideas, especially his conception of multiple realities and his theory of relevance. This is, in turn, an attempt to explore constitutive aspects of social reality in the light of the "sociological imagination," which would lead to a conception of an adequate sociological theory.