Aphorism 31

The inimical forces, partly psychical, partly physical, to which our terrestrial existence is exposed, which are termed morbific noxious agents, do not possess the power of morbidly deranging the health of man unconditionally1; but we are made ill by them only when our organism is sufficiently disposed and susceptible to attack of the morbific cause that may be present, and to be altered in its health, deranged and made to undergo abnormal sensations and functions - hence they do not produce disease in every one nor at all times.

1 When I call a disease a derangement of man's state of health, I am far from wishing thereby to give a hyperphysical explanation of the internal nature of disease generally, or of any case of disease in particular. It is only intended by this expression to intimate, what it can be proved diseases are not and cannot be, that they are not mechanical or chemical alterations of material substance of the body, and not dependant on a material morbific substance, but that they are merely spirit-like (conceptual) dynamic derangements of the life.