In this study, a conceptual system is outlined for the educational science sub-discipline of adult education. Adults' attending instruction or not attending instruction is conceptually specified. Focusing as it does on a cardinal event of adult education, this represents a first step toward a system for the educational science sub-discipline of adult education. Attending instruction is mainly understood as action, and non-attending instruction as behavior. Instruction is a system of educational actions in which the teacher orients a subject to the educand in order to change his or her psychic dispositions. (Contains 1 table.)