Proving Medicines

Organon Aphorism §119

As certainly as every species of plant differs in its external form, mode of life and growth, in its taste and smell from every other species and genus of plant, as certainly as every mineral and salt differs from all others, in its external as well as its internal physical and chemical properties (which alone should have sufficed to prevent any confounding of one with another), so certainly do they all differ and diverge among themselves in their pathogenetic – consequently also in their therapeutic – effects. Each of these substances produces alterations in the health of human beings in a peculiar, different, yet determinate manner, so as to preclude the possibility of confounding one with another.

Samuel Hahnemann, Organon of Medicine, 6th edition, translated by William Boericke (1922, public domain). Checked word for word against the 1922 printing in October 2026.

Study notes for this aphorism are not published yet. They appear here once a homeopath has reviewed them.