Examples of "freely-going" processes: Left: the combustion of fuel, in this case wood, in a campfire, which is the reaction of a hydrocarbon (methane shown below) with oxygen to produce water, carbon dioxide, light, and fire: Center: A photo of copper metal in a beaker of nitric acid wherein oxidation of copper metal by nitric acid, a process having the chemical equation shown below, produces nitric oxide (NO) gas which is immediately oxidized in air to form brown nitrogen dioxide (NO2) gas. The copper atoms lose two electrons to form Cu2+ ions which give a blue color in water. [6] Right: A CartoonStock.com love cartoon entitled “Burning love”, depicting love as a combustion reaction (see: human chemical reaction theory), which in the case of a human reproduction reaction type combustion reaction has the following time-accelerated chemical equation form: [7] which is the reaction of two human molecules, AB (man + sperm) and CD (woman + egg), produce, in the process of love the chemical reaction, a dihumanide molecule A≡C and a new precipitate human molecule BD (child). [8]

“In the preceding discussion we have considered a chemical process which is in some way harnessed for the production of useful work. We may now turn to the far more common case of a reaction which runs freely, like the combustion of a fuel, or the action of an acid on a metal. In other words, let us consider a system which is subject to no external forces, except a constant pressure exerted by the environment.”

“Suppose that this hypothetical experiment could be realized, which seems not unlikely, and suppose we could discover a whole chain of phenomena [evolution timeline], leading by imperceptible gradations form the simplest chemical molecule to the most highly developed organism [human molecule]. Would we then say that my preparation of this volume [Anatomy of Science] is only a chemical reaction [extrapolate up approach], or, conversely that a crystal is thinking [extrapolate down approach] about the concepts of science?”