Organon §64
Initial action
As seen from the following examples, during the initial action of the artificial disease potences (medicines) upon our healthy body, our life force appears to comport itself only conceptively (receptively, passively as it were) and appears as if it were forced to allow the impressions of the artificial potence impinging from without to occur in itself, thereby modifying its condition.
Counter-actions
The life force then appears to rally in one of two ways:
1. Where there is such a one, the life force brings forth the exact opposite condition-state (counter-action, after-action) to the impinging action (initial action) that has been absorbed into itself. The counter-action is produced in as great a degree as was the impinging action (initial action) of the artificial morbific or medicinal potence on it, proportionate to the life force's own energy.
2. If there is no state in nature exactly opposite to the initial action, the life force appears to strive to assert its superiority by extinguishing the alteration produced in itself from without (by the medicine), in place of which it reinstates its norm (after-action, curative-action).