First Section: Religious Dualism.

...threatens to disturb the organs, [the impulse remains] unsatisfied, and the sensation is unpleasant, which at greater intensity turns into pain. This sentence completes the thought from the previous page regarding how the body reacts to stimuli that exceed its natural capacity to process them.

According to the laws of nature, every action brings forth a reaction, because every stimulated force strives to express itself. Sensation, stimulated by an external stimulus, awakens the impulse impulse: Trieb – a natural urge or driving force that prompts a living being to act, which makes use of the voluntary muscles in order to express life. Internal activity in the life of the brain comes into contact with the muscles through this impulse; internal movement becomes external, and the opposition between the outer and inner is balanced. Voluntary muscle movements correspond to sensory impressions, in that a brain stimulus, conducted to the peripheral parts of the nervous system, produces a change in the body through muscular activity. In involuntary movements, modifications of the common feeling common feeling: Gemeingefühl – the internal sense of one’s own physical existence and state of health, distinct from the five external senses find expression.

Becoming aware of the external world through the senses is conditioned by becoming aware of one’s own corporeality, for without a common feeling of one’s own existence, the sensation of a foreign existence is unthinkable. External objects act upon the sensory organs and, through the nerves, upon the brain, which is thereby determined in a corresponding manner.

In inorganic nature, the reciprocal relationship to a foreign body first shows itself in the equalization of thermal conditions The author refers to the way two objects of different temperatures reach an equilibrium when they touch; in plant life, the process of equalization manifests in modifications of cellular nutrition; in animal life, the opposition to the external world is mediated by the nervous system, and life becomes apparent through voluntary movement as a higher form. In humans, the flowing abundance of sensations and sensory impressions finds an even higher point of equalization in consciousness and self-consciousness, beyond the compensation provided by muscle movement. The human individual shares this with animal life: the nerves affected by sensory impressions run to the brain or spinal cord, from where they reach the voluntary muscles and, distributing themselves into every fiber of flesh, claim these as organs of movement. The char—

original: "Naturgesetz, Empfindung, Trieb, Muskelbewegung, Nervensystem, Gemeingefühl, Bewusstsein, Selbstbewusstsein, Gehirnleben"