sentences: "Vis nervosa" was described as a latent nervous force possessed in the nerves, and the term "sensorium commune" was defined as the point of reflection between the sensory and motor nerves.Prochaska used the term "vis nervosa" as a direct analogy to Isaac Newton's "vis gravitans", due to his belief that "vis nervosa" was an elemental form of energy, that could not be observed except through its effects such as reflexes and reflections, adhering to natural laws that could be described (as could Newton's theories of gravitation), but at the same time were unexplainable.