This article addresses the concept of complexity and its effect on the logic of the design problem. It argues that the competing interpretations of complexity represent a logical antinomy (in the Kantian sense), and that this prevents the concept's further elaboration. It is necessary therefore to address the conditions that have produced this antinomy. Using the Hegelian category of the determination of reflection, complexity is then reconsidered as the effect of the circular logic by which a social system is defined. The complexity of the design problem is then redefined on the basis of this elaboration.