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]$AB + CD \to A \equiv C + BD \,$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 processes, a freely-running or "freely going" process is a reaction which runs freely, like the combustion of a fuel or the action of an acid upon metal, and thus constitute systems subject to no external forces except the constant pressure of the atmosphere. In the original 1923 words of American physical chemist Gilbert Lewis: [1]

“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.”

Examples of freely going reactions are shown adjacent.

Governing equation
In freely running reactions, the Lewis inequality for natural processes governs the process:

If, conversely, the process is in some way harnessed for the production of useful work, e.g. when the electrical energy produced from reactions of a Galvanic cell (or battery) is coupled or connected to a system external motor or other electrical device, used, for instance, to light a bulb, then it is a universal rule that if any isothermal-isobaric process is to occur with finite velocity, it is necessary that:

where$w' \,$ is the net work. [1] The work of Adriaan de Lange (1982) and—inspired by de Lange, the work of Gavin Ritz (2001), seem to be the only ones to have perused the implications of this latter coupling “net work” factor in sociological terms (see: human free energy).

Evolution
The process of chnopsological evolution (biological evolution) is a "freely going" process, a type of ongoing green combustion, or "green fire" as Russian geochemical mineralogist Vladimir Vernadsky, in 1926, described the dynamics of change in the "biosphere" (sphere of life) in chemical thermodynamic terms, sparked daily by the heating of the light from the sun. [2]

While the main work of Lewis wasn't necessarily concerned with applications of his chemical thermodynamics derivations in evolution theory, he did, to note, in his 1925 Silliman lectures, turned book Anatomy of Science (§7: Non-Mathematical Sciences), delve into the tricky question of evolution of the animate things/living things (terms which he rotates usage of), commenting:

“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?”

In 1982, in loose connection to 1923 Lewis definition that the Lewis inequality governs freely going Earth-surface-attached reactions, in 1982 Canadian zoologist Daniel Brooks and American systems ecologist Edward Wiley published there very controversial 1982 article "Victims of History: a Nonequilibrium Approach to Evolution", wherein the gave the following "equation for evolution": [4]

$E = \frac{dS_i + dS_c + dS_e}{dt} \$

where E represents evolution, dSi stands for the change in entropy levels of information, dSc for changes in entropy levels of cohesion, and dSe for changes in something else (add), an equation which supposedly is time derivative portmanteau or blend of Prigogine entropy and Shannon entropy, which of course is the reason why the article resulted in such a backlash (see: Brooks-Wiley theory). [5]

References
1. Lewis, Gilbert N. and Randall, Merle. (1923). Thermodynamics and the Free Energy of Chemical Substances (pg. 160). McGraw-Hill Book Co., Inc.
2. Vernadsky, Vladimir I. (1926). The Biosphere (free energy quote, pg. 44; chance quote, pg. 44; transformers, pg. 47; nitrogen and free energy, pg. 58; speed of transmission, pgs. 65-66; equilibrium, pg. 75; part one: The Biosphere in the Cosmos, pgs. 43-90; part two: The Domain of Life, pgs. 91-150; living matter, pg. 53-56; keyword: “internal energy”, pg. 60; J.W. Gibbs, pg. 97; sense its pressure”, pgs. 59-62, 76). Copernicus.
3. Lewis, Gilbert N. (1925). The Anatomy of Science, Silliman Lectures; Yale University Press, 1926.
4. Willey, Edward O. and Brooks, Daniel R. (1982). “Victims of History: a Nonequilibrium Approach to Evolution” (abs), Systematic Zoology, 31:1-24.
5. Lewin, Roger. (1982). “A Downward Slope to Greater Diversity”, Science, 24(217): 1239-40.
6. (a) Copper Metal In A Beaker Of Nitric Acid (1992) – fphoto.photoshelter.com.
(b) Balancing equations – CliffNotes.com.
7. Burning love – CartoonStock.com.
8. (a) Thims, Libb. (2007). Human Chemistry (Volume One). Morrisville, NC: LuLu.
(b) Thims, Libb. (2007). Human Chemistry (Volume Two). Morrisville, NC: LuLu.