A theory of signs is presented to arrive at a model of mind that provides a smooth transition from inanimate matter to the thinking brain. Principles of information theory and semiotics are invoked to create a conceptual scheme that can contribute to an understanding of the "mind-body problem." The thesis is pursued that in living systems, as opposed to inorganic ones, there occurs the phenomenon of semiotic transmission of information. The result is a "dualistic-materialist" position; the dualism arises from the fact that at the beginning of life a set of processes comes into being different from those of the inorganic world. This model has implications for psychology and psychoanalysis. It allows for semiotic systems at different levels--e.g., the molecular, the neural network, the language system, and higher mental functions--to be integrated. Analytic concepts such as free association, clinical technique, feedback systems, personality structure, transference, and repetition compulsions can be understood in both biological and semiotic terms. This model interdigitates with linguistic studies already done in psychoanalysis, as well as with biological models extrinsic to the field.