There is something striking and different about Hahnemann in Köthen that stands out from the rest of his life as unusual. It is the fact that he finally nailed his colours to the mast of vitalism by declaring homeopathy's allegiance to the innate vital powers, the miasm theory and the invisible potency energy of tiny doses. Before the 5th Organon, these were merely half-suggested hints and shadows never declared overtly. The 5th Organon changed all that, but why? Was it the result of a search for a meaningful rationale? the task we have is to see what he had learned from the events of Leipzig.