ABSTRACT
Every science passes through a phase in which it considered its basic subject matter to be some sort of substance or structure. Fire was identified with phlogiston; heat with caloric; and life with vital fluid. Every science has passed beyond that phase, recognizing its subject matter as being some sort of process; combustion in the case of fire; random thermal motion in the case of heat; and certain kinds of far from thermodynamic equilibrium in the case of life.
