Thus far, cognitive studies on concept have not focused on its creative features. The process of concept generation is still an open issue. In order to clarify the concept generation process, we discuss design from the perspective of creativity. First, we consider previous studies on design and segregate design into three categories: drawing, problem solving, and pursuit of the ideal. Next, we discuss each category from three perspectives: time direction, driving force, and creativity as a rational novelty. Following this, we define the generation process of a design image as a model of concept generation related to metaphors, abductions, and operations of abstract concepts. Finally, we redefine design -- that is the process of composing a desirable figure toward the future -- and address that creativity in design is a criterion for the desirable figure on the basis of the knowledge gained from our studies.