This thesis examines the epistemology of artefact comparisons in early Greek natural philosophy and medicine. Various thinkers frequently employed the structure and/or functioning of man-made artefacts to improve their understanding of a target domain in which direct observation is hindered or impossible, such as in meteorology, cosmology, or human physiology. My thesis mainly focusses on fragments and reports of the so-called ‘Presocratics’, but also encompasses Hippocratic and Pythagorean texts, thereby placing the use of artefact comparisons as an epistemological tool in the sixth to mid-fourth centuries BC in context.

This thesis aims to counter a prevalent scholarly attitude towards these early Greek comparisons in natural philosophy and medicine: regarding them as theoretically unessential. The disregard for the epistemic importance of comparisons can be gauged from the scattered attention they have received. Most handbooks and companions on early Greek natural philosophy only rarely feature comparisons. Whereas some individual comparisons have been the topic of discussion in book sections and articles, many others have barely ever been treated.

The obvious exception to the neglect of the significance of comparisons is Lloyd’s excellent Polarity and Analogy from 1966, which remains the most complete study of early Greek (artefact) comparisons to date. My thesis intends to remedy two shortcomings of Lloyd’s landmark study. First, Lloyd’s fairly broad definition of an analogy as ‘any mode of reasoning in which one object or complex of objects is likened or assimilated to another’ (page 175) led to his undifferentiated inclusion of comparisons which work epistemologically in different ways. Second, while the majority of Lloyd’s analyses of individual comparisons are compelling and insightful, Polarity and Analogy does not theoretically explain which properties of the source domain are compared to which properties of the target domain, nor how this process of likening happens.

This thesis employs a psychological theory of analogy, called the ‘structure-mapping theory of analogy’, developed in the 1980s by Professor Dedre Gentner. The structure-mapping theory of analogy provides criteria to distinguish between literal similarity and analogy, and to pinpoint the generative, corroborative, and didactive capacities of analogies. Employing this theory, I highlight previously misunderstood or overlooked aspects of those early Greek artefact comparisons, such as additional properties involved in the mapping from the source domain to the target domain and new reasons why thinkers might have included these comparisons with artefacts.

This thesis demonstrates that all early Greek artefact comparisons contain heuristic, corroborative, and explanatory functions which are epistemologically essential and could neither (easily) be left out nor be substituted with a more straightforward, non-comparative description. The precise nature of the epistemological advantage offered by these comparisons depends on their locations on the scale of kind of comparison (from literal similarity to analogy) and on the scale of deviation from standard usage (from normal use to extra-ordinary use by construction or adaptation). The first three chapters each discuss a group of comparisons from a different area on those two scales, and the fourth chapter further examines the use of a clepsydra as a source domain for various different kinds of comparisons by different thinkers. In short, this thesis sheds new light on the importance of early Greek artefact comparisons, showing that they are integral parts of the cosmological, meteorological, and physiological Greek theories of the 6th, 5th, and early 4th centuries BC.