This study presents a new theory to explain the neural origins of human mind. This is the psychomotor theory. The author briefly analyzed the historical development of the mind-brain theories. The close relations between psychological and motor systems were subjected to a rather detailed analysis, using psychiatric and neurological examples. The feedback circuits between mind, brain, and body were shown to occur within the mind-brain-body triad, in normal states, and psycho-neural diseases. It was stated that psychiatric signs and symptoms are coupled with motor disturbances; neurological diseases are coupled with psychological disturbances; changes in cortico-spinal motor-system activity may influence mind-brain-body triad, and vice versa. Accordingly, a psychomotor theory was created to explain the psychomotor coupling in health and disease, stating that, not the mind-brain duality or unity, but the mind-brain-body triad as a functional unit may be essential in health and disease, because mind does not end in the brain, but further controls movements, in a reciprocal manner; mental and motor events share the same neural substrate, cortical, and spinal motoneurons; mental events emerging from the motoneuronal system expressed by the human language may be closely coupled with the unity of the mind-brain-body triad. So, the psychomotor theory rejects the mind-brain duality and instead advances the unity of the psychomotor system, which will have important consequences in understanding and improving the human mind, brain, and body in health and disease.