Explanatory models for homeopathy: from the vital force to the current paradigm

Facing claims for and against the scientific status of homeopathy, one is entitled to ask: is there a scientific model for homeopathy? In this study we reconstructed the model put forward by Hahnemann. The results showed that it was essentially based on the assumption of a 'vital force' exclusive to living beings. While the vital force was a basic element of 18th-century science, the existence of such a sui generis force of nature was refuted with the formulation of the law of the conservation of energy by mid-19th century. As a function of that fact for homeopathic theory, we discuss the history of the rise and demise of the theory of the vital force from the last quarter of the 18th century to 1830. Finally, we call the attention to the paradigm shift biology underwent starting at the end of the 19th century as the framework for contemporary views on the functioning of living beings and consequently, of the effects of pharmacological agents on them.