Joseph Lister's antiseptic system of surgical treatment was developed over a period of about thirty-five years between 1865 and 1900. Lister's theory and practice have been regarded as the foundations on which were built modern aseptic surgery and the conceptual framework deemed inseparable from it, the germ theory of disease. Refining the practice of healing in a clot, and developing a physiological and pathological theory of how this occurred, or failed to occur, were central to Lister's work over the fifteen years. The theory of inflammation can be discerned as a structuring element in Lister's famous papers of 1867, which announced his antiseptic surgery. Lister claimed that he had, on the basis of his experimental work on inflammation, come to the conclusion that 'the essential cause of suppuration in wounds is decomposition'. Lister's work has been fairly well chronicled and will only be outlined here in so far as they demonstrate the pathological framework employed by Lister and his contemporaries.