Abstract
A classification of hypotheses concerning the mode of action of potentized medicines
is proposed. Hypotheses are analysed according to their adequacy for explaining the
phenomenon. 2 main groups are proposed, depending on the active or passive role of
the organism during homoeopathic treatment, with subdivisions and differences described.
Links with the main body of knowledge must be maintained so the hypotheses may gradually
acquire the status of a successful explanation. The need to introduce the Hahnemannian
concept of biological reaction stems from the principles of homoeopathy.