the complex ways in which adults structure their thinking based on the complicated nature of adult life. It is an extension of Jean Piaget’s concept of formal operations (see formal operational stage), which are developed in adolescence, to adult cognition and includes an understanding of the relative, nonabsolute nature of knowledge; an acceptance of contradiction as a basic aspect of reality; the ability to synthesize contradictory thoughts, feelings, and experiences into more coherent, all-encompassing wholes; and the ability to resolve both ill- and well-defined problems.