This paper argues that a generative structure is not equivalent to a coherent system. Using examples from semiotics, biology, systems theory, and Lie algebra, it develops a distinction between dyadic generation and triadic regulation. Dyadic relations, exemplified by Saussure's signifier-signified model and the binary Lie bracket, are shown to generate differences, relations, and new possibilities. However, generation alone does not explain how coherence, stability, or meaning are maintained. Drawing on Peirce's concept of Thirdness, the paper proposes that a mediating regulatory relation is required for organized persistence. This regulatory function appears across domains as interpretants in semiotics, homeostatic and multiscale regulatory networks in biology, and higher-order constraints such as the Jacobi identity in Lie algebra. The comparison is not one of identity but of shared logical architecture: generative relations require regulatory constraints if they are to constitute coherent systems. The resulting framework is summarized as a progression from difference → relation → regulation → coherence, providing a rigorous account of how two-sided structures become integrated wholes while preserving their distinctions.