For all human sciences, understanding of how the mind works requires a new theory that starts from the assumption of potential infinite variability of human symbolic forms. These forms are socially constructed by the person who moves through an endless variety of unique encounters with the world. A theory of symbolic forms needs to capture the essence of hyper-dynamic, irreversible nature of the stream of consciousness and activity. Henri Bergson can be considered to have opened the door to the investigation of both the irreversible processes in nature (later to have been enfamed by Ilya Prigogine), and the study of development of the mind (cognitive epistemology of Jean Piaget and the cultural-historical perspective of Pierre Janet, Lev Vygotsky and Alexander Luria). The perspective outlined here builds on the cultural-historical perspective through a focus on of semiotic autoregulation of the mind. The human mind is regulated through a dynamic hierarchy of semiotic mechanisms of increasingly generalized kind, which involves mutual constraining between levels of the hierarchy. It is demonstrated that semiotic mediation leads to a triplet of personal-cultural constructions – a new symbolic form, a meta-symbolic form, and a regulatory signal to stop or enable the construction of further semiotic hierarchy. In everyday terms—human beings produce new problems, together with new efforts at solving them, and make decisions when to stop producing the former two. Hence, semiotic mediation guarantees both flexibility and inflexibility of the human psychological system, through the processes of abstracting generalization and contextualizing specification. Context specificity of psychological phenomena is an indication of general mechanisms that generate variability. Scientific investigation of human psychological complexity is necessarily oriented to the study of variability within the individual person’s psychological time-space.