
The "ABC model" of the so-called free operation of the will or free will: (A) retinal molecule in ground state (normal state); (B) light (or one or more photons) with a frequency of 400 to 700 nm absorbs into the the carbon atom (note: atom shown is actually beryllium) at the 11 position, thus causing (exchange force) an electron to jump up in orbital position (excited state); (C) the retinal molecule reacts to this by "moving" to the straightened position, a short-lived heightened energy configuration (see also: will to power).

The "ABC model" of the so-called free operation of the will or free will: (A) retinal molecule in ground state (normal state); (B) light (or one or more photons) with a frequency of 400 to 700 nm absorbs into the the carbon atom (note: atom shown is actually beryllium) at the 11 position, thus causing (exchange force) an electron to jump up in orbital position (excited state); (C) the retinal molecule reacts to this by "moving" to the straightened position, a short-lived heightened energy configuration (see also: will to power).

In hmolscience, ABC model (TR:10) is simplified three step description of the light-mediated mechanism through which the 3-element molecule retinal straightens, when in the presence of light of wavelength about 550 nm, employed to explain how a like, albeit more complex, mechanism of movement operates in the hydrocarbon mental processing the 26-element human molecule (person), to thus give a conceptual understanding of the external force / internal force nature of the will and ‘choice’, as this is a crucial concept hinging commonly in religion vs. science debates—in fact, it is commonly cited as the crux of the issue, in respect to morality and meaning. [1]

Mind-body problem
The ABC model solves the famous mind-body problem, i.e. the C20H20O molecule has a conceptual "body" (41 atom atomic structure) and "mind" (C11-C12 region of the molecule), according to which 550 nm photons activate a so-called state of forced "awareness" (i.e. conscious mind, as Descartes might have reasoned), according to which the molecule "chooses", not to imply free will, to straighten in the excited state; as shown below:

when the stimulus is removed (light taken away) the "mind" chooses to retract back to the bend configuration, i.e. the normal or unconscious state, speaking anthropomorphically.

Human choice is but a more elaborated version of this, where in stored memories delay the choice, for seconds, minutes, or hours, or days, for simple choices, or for months, years, or decades, for more complex choices. The Libet experiment gives insight into this mechanism.

Internal force
The internal force here is the set of electromagnetic exchange forces existing and operating in the bonding dynamics of the C11-C12 carbon atom junction.

External force
The external force here is the light transmitted from some external source (e.g. sun light) directed at and entering the volumetric region of the retinal molecule.

References
1. (a) Thims, Libb. (2007). Human Chemistry (Volume One) (retinal molecule, pg. 198). Morrisville, NC: LuLu.
(b) Thims, Libb. (2007). Human Chemistry (Volume Two). Morrisville, NC: LuLu.
(c) Thims, Libb. (2008). The Human Molecule (issuu) (preview) (Google Books) (docstoc) (retinal molecule, pgs. 60-61). LuLu.