Aphorism 31:
The Law of Susceptibility: Aphorism 31 and the Conditional Nature of Disease
In Aphorism 31, Samuel Hahnemann introduces a crucial distinction between natural diseases and medicinal forces. While he previously established that medicines have an “absolute, unconditional power” to affect the body, he here explains that natural morbific agents do not possess such power.
Disease is Conditional
Hahnemann asserts that the “inimical forces”—whether psychical (mental/emotional) or physical—to which we are exposed daily do not derange human health unconditionally. We are made ill by these noxious agents only when our organism is “sufficiently disposed and susceptible” to their attack.
This principle explains a common observation in medicine: natural diseases do not produce illness in every person nor at all times. For an infection or a psychological shock to trigger a disease, there must be a matching vulnerability within the individual’s vital force.
Defining Dynamic Derangement
In a significant footnote to this aphorism, Hahnemann clarifies his definition of disease. He states that calling disease a “derangement of man’s state of health” is not meant as a “hyper-physical explanation” but as a rejection of materialistic views. He emphasizes that:
- Diseases are not mechanical or chemical alterations of the body’s material substance.
- Diseases are not dependent on a “material morbific substance”.
- Instead, they are “merely spirit-like (conceptual) dynamic derangements of the life”.
The Physician’s Insight
Aphorism 31 teaches the practitioner that health is a state of resistance and that illness is the result of a specific interaction between an external influence and an internal susceptibility. By understanding that natural disease is conditional, the physician can better appreciate why medicines—which act unconditionally—are such powerful tools for overcoming these often haphazard and variable natural afflictions.
Conclusion: The Shield of Health
In Hahnemann’s framework, Aphorism 31 serves as a reminder that the human organism is not a passive victim of its environment. It is a dynamic entity that only “permits” disease when its internal harmony is already compromised or predisposed. This sets the stage for Aphorism 32, where Hahnemann contrasts this conditional nature of disease with the unconditional power of homoeopathic medicines to effect change at any time.
