When Samuel Hahnemann devised homoeopathy he constructed multiple arguments that both vehemently supported his new system and criticized the conventional medical practice of his day. At the end of the 19th century when homeopathy had grown within Britain and America, homeopaths failed to make use of some of Hahnemann’s most successful arguments. Instead, homeopaths found themselves lose significant cognitive ground to their long time conventional rivals with the dawn of the 20th century, a ground they have not yet recovered. This paper uses the theoretical framework of Berger and Luckmann to analyse the dynamics of the arguments used against homeopathy and suggests that homeopaths failed to adopt a universalizing medical explanation that was available to them: the reverse action of drugs. Had they used this argument homoeopaths could have explained conventional medicine successes within their own universe of meaning and thus neutralized the impact of conventional on their practice. The implications of these conclusions for the future survival and success of homoeopathy are considered.