In physiology a function is a normal and specific action of any tissue, organ, or part of a living animal or plant, and is applied only to the action of an organ. A function is a peculiar action of an organ which has a duty to perform. The performance of a physiological duty is a function. A physiological function is performed in obedience to a command. The functions include all of the vital phenomena of plants or animals, understood to be performed in a proper manner, unless otherwise stated.
All functions are vital, directed by vital force, a force directed by an intelligence.
Mechanical, thermal, chemical, electrical, magnetic, cohesion, gravity, centripetal and centrifugal forces differ from vital force which depends upon two original and independent elements, spirit and matter. Vital force may be divided into neurism, nerve force, and bathism, growth, force, energy. These two divisions of vital force are under the direction and control of individualized spirits. Phrenism, that force is of the mental, under the direction of the human will. Vital force is inherent in the organ or organism.