A clear definition of its subject and correct application of its tenets are the basis of any science. Conversely, the want of a unanimous understanding of its constituting principles by the homeopathic community is undermining its scientific practice, research and discussion. To facilitate these, first and foremost the Principle of Similars, similia similibus curentur, has to be clarified and assessed in terms of its theoretical meaning, historical development, and epistemological status. Hahnemann’s conceptions, explanations, and appraisals were not static but evolved and hardened over the years, especially from 1796 to 1810. While initially he related similia similibus to an imitation of similar cures by nature and proposed it as an opposition to contraria contrariis, he later generalised it to the treatment of any disease. Whilst originally he considered it to be a hermeneutical principle, or a hint towards a curative remedy, Hahnemann later dogmatised it as the only truth. Considering advances in epistemology and theory of medicine, however, the Principle of Similars may not be assessed as a final truth or natural law to be empirically verified or falsified for good, but rather as a practical maxim, guiding the artist of healing in his/her curing of diseases rationally and individually.