I summarize three millennia of exploration of mind and brain, with the conclusions that observations on brain biology in relation to behavior provide our best source of new understanding, that we have sufficient data to provide new insights into the human condition, that we need new concepts by which to organize the data, and that recent developments in nonlinear dynamics can give us the necessary foundation.
I review the nature of state variables. Dynamics is the study of change in the state of something. In brains that thing has been identified over the centuries with nerve spirits, energy, information, and quanta. I reformulate the mind-brain relation by defining Neuroactivity as the structure of brain operations and "mind" as the structure of behavior.
I explain how to model Neuroactivity with dynamics from measurements of electrochemical brain operations. To that end I define the emergent activities of masses of neurons forming populations, for which some but not all of their macroscopic properties can be derived from the microscopic properties of their component neurons.
I sketch the relations between observed movements of bodies and minds as the structure of behavior. I propose a central role for the limbic system as the organ of intentionality. It provides for the senses of time, space, and expectancy as the contexts for purposes, goals and predictions.
I close the loop by calculating statistical relations of Neuroactivity in brains to thoughts I infer from observations of behavior. To that end I define thought as fleeting actualization of intentional structure, and representation as a product of behavior that is used to cross the solipsistic gulf.
I describe learning, by which intentional structures stretch forth and change themselves through self-organizing, chaotic dynamics. I infer that neurohumoral mechanisms exist in mammals for unlearning by a meltdown of intentional beliefs without loss of procedural and declarative memories, which enables understanding between self-organizing brains by cooperative actions. We experience this as falling in love.
I place qualia of experience inside the solipsistic barrier, with communication only by making representations. The qualia include awareness and its accompanying triad of self, cause, and free will. They are essential properties of societies, individuals having evolved to function in groups, not in isolation.