The Ethical Infinitesimal: Gustav Fechner’s Inner Border in the Metaphysics of Psychophysical Parallelism
In the manifold tapestry of metaphysical speculation, few have dared to extend their vision into the troubled realm where the soul meets the sum of natural law. It is in this elusive territory that one encounters Gustav Theodor Fechner (1801–1887), a name more often confined to the appendices of psychological doctrines, rather than granted the dignity of metaphysical scrutiny. Known to today’s few readers as progenitor of psychophysics and midwife to the mathematical soul of perception, Fechner is too easily mistaken for a mere empiricist—a misreading as grievous as confusing Leibniz for a watchmaker. For Fechner, unlike the modern priesthood of experiment and data, trafficked in souls, stages of consciousness, and what he termed the “daylight view”—a metaphysical vision in which matter and spirit do not merely interact, but resonate in parallel.
What has yet to be adequately appreciated, however, is the subtle architecture of Fechner’s metaphysical ethics—that is, the infinitesimal pivot upon which his entire psychophysical parallelism turns, suggesting a radical reconciliation between determinism and divine individuality. Through this neglected detail—the so-called “inner border of the infinitesimal psychic”—we encounter Fechner not as proto-psychologist but as moral metaphysician of the first order.
To comprehend this inner border, we must begin with Fechner’s presupposition that reality is constituted by layers of experience, ranging from the unconscious to the cosmically aware. In works such as “Zend-Avesta” and “Nanna, or the Soul-life of Plants,” Fechner posits a spiritual continuum throughout nature, up to and including the Earth itself. Yet it is in the Zwischenreich—the “intermediate realm”—between mind and matter, where he locates the true marvel of nature: the possibility of deterministic law (quantifiable, experimentable, repeatable) existing in perfect harmony with spiritual inner life (singular, indivisible, moral). He thereby constructs—though without the formal vocabulary—the groundwork of psychophysical parallelism, later mythologized by Spinoza’s admirers.
But it is one sentence, scarcely noted in modern commentary, buried in Part III of “Elemente der Psychophysik” (1860), wherein Fechner introduces the concept which demands our full philosophical attention:
“Zwischen einem Wert von Null Bewußtsein und dem kleinsten noch gerade bemerkbaren Bewußtsein liegt eine Welt, die nur die Seele kennt.”
(“Between a value of zero consciousness and the smallest barely perceptible consciousness lies a world known only to the soul.”)
Herein lies the fundament: Fechner suggests that even below the threshold of measurable mental activity—what moderns call ‘bare perception’—there pulses a strata of inner life which, though inaccessible to empirical registration, is nonetheless constitutive of the continuum of experience. It is the metaphysical equivalent of the mathematical infinitesimal: not nothingness, but that which bridges nothing to something. In this infinitesimal ethical self lies the root of all later moral discernibility.
Fechner’s implication, subtle though it be, is that ethical agency emerges not at the height of reflective reason, but in these immeasurable thresholds of being, where spiritual stirrings begin their ascent into the daylight of consciousness. This proposition—radical in its time and scarcely palatable now—uncrowns reason from its tyranny as sole arbiter of the good. The continuum of inner awareness is moral not by virtue of rational choice, but by virtue of its being. The metaphysical substratum of the soul, even when in the murky waters below awareness, is still ethically related to the cosmos.
Scholars such as Rainer Mausfeld^1 have recently hinted at the possibility that Fechner anticipates certain phenomenological insights, but none have dared trace the moral implications of this infinitesimal border. If the soul is constantly vibrating along this continuum—even in moments of bodily sleep, catalepsy, vegetative states—then this border becomes an ethical membrane: a site where the divine cosmical intent and the individual particular merge. Thus, moral responsibility, for Fechner, is not a juridical imposition upon willing subjects, but the unfolding of inward resonance, present even at the pre-conscious level.
Let us juxtapose this insight with contemporary neurology’s distinction between ‘subliminal’ and ‘supraliminal’ perception. Whereas empiricism would terminate inquiry at the limits of the perceptually verifiable, Fechner, prophet that he was, saw the danger of confining the soul’s agency to what could be introspectively accessed. He maintained that the soul’s temporality and continuity transcended the pulses of exterior perception. There are, he insists, exercises of the soul too small for consciousness to perceive—so-called “psychical atoms” whose ethical value lies not in being known, but in being lived.
This leads us to the profoundly non-modern character of Fechner’s philosophy. He dares to place being before reflection—and, what is more, goodness before knowledge. Whereas the Kantian paradigm insists upon the primacy of duty arising from rational law, Fechner assigns the origin of moral behavior to an inner, dynamic continuity with the spiritual life of the cosmos—even as it courses through stones, plants, stars.^2 His conception is less that of the moral individual struggling against nature, and more that of a soul harmonizing with the song of the universe, sometimes faint, sometimes unheard, but always real.
The practical implications are immense. For if the soul has agency in its infinitesimal acts, then society, education, and spiritual development must concern themselves not merely with overt actions, but with the nurture of those pre-cognitive dispositions in which righteousness takes root. One may smile, perhaps, at Fechner’s tender care for the inner lives of ferns or for the planetary geist of Venus—but the moral philosophy underlying such anthropocosmism^3 refutes the crass subject-object dualism still dominant in Anglo-Saxon moral theory.
Like Plotinus’ lush metaphor of the One radiating downward in diminishing emanations, Fechner’s theory of psychic infinitesimals suggests an ethics of elevation—a slow and sacred ascent in which every particle of soul possesses not merely immanence, but moral trajectory.
Any metaphysical system which fails to account for the inwardness of being at its lowest gradations must likewise fail to explain the mystery of good arising in a world governed by necessity. Fechner’s doctrine, obscure though it may be, offers a path forward—a metaphysics that does not ask us to fabricate soul from matter, but to recognize spirit where it has always dwelt, even in the infinitesimal.
Thus must we read Fechner not as footnote to psychophysics, but as moral insinuator into the scientific proud-flesh of the nineteenth century. His borders are thresholds, his minutes are immensities; and in his ethics of the infinitesimal, one finds an echo—a whisper—of a unity long abandoned by our mechanized modernities.
By Martijn Benders – Philosophy Dep. of the Moonmoth Monestarium
soul, psychophysics, ethics, infinitesimals, german idealism, perception, metaphysical continuity
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^1 See Mausfeld, Rainer. “Das Psychophysische Dilemma.” *Zeitschrift für Philosophische Forschung*, vol. 68, no. 1, 2014, pp. 1–27.
^2 For a comprehensive account of spiritual immanence in Fechner, see Taddicken, Uwe. *Pflanzen und Planeten: Die Kosmische Ethik Gustav Fechners*. Leipzig: Akademische Verlagsanstalt, 1991.
^3 A term formalized by later German thinkers to denote the unity of cosmos and consciousness—a kind of applied pantheism, presaged by Fechner’s Earth-soul theory.