The Ancient Origins of Theoretical Mechanics

The Ancient Origins of Theoretical Mechanics

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Vitruvius, M. L. Vitrvuio Pollione De architectura, 1524</a><br>
Original Source owned by the Werner Oechslin Library, Einsiedeln

The use of mechanical tools predates any theoretical attempt to explain their function. The oldest known of these attempts date to the time of ancient Greece. The early Greek treatises not only changed the conditions for the construction of mechanical devices but also provided a model case for the structure of scientific theories: experiences of practitioners are traced back to principles from which they can be deduced as necessary implications. Paradigmatically, the work of Archimedes on the equilibrium of planes embodies this notion of a deductive theory. The investigation of the emergence of this notion of a deductive theory in ancient Greece and the study of its impact on the later development of mechanics is a central activity pursued to understand the emergence of theoretical mechanics (Peter Damerow, Peter McLaughlin, Jürgen Renn). The Mechanical Problems of Aristotle (or of one of his disciples) played a crucial role in the early development of theoretical mechanics. Traditionally this treatise has been studied either with philological methods to evaluate the authenticity of attribution to Aristotle as its author, or from the viewpoint of later mechanics as an early application of the law of the lever. In contrast to such investigations, the treatise has been analyzed here against the background of the multilayered knowledge system of mechanics as a transformation of existing knowledge into a new form. In applying this method, it was shown that the treatise is not based on any theoretical explanation of the law of the lever, but rather on a principle that represents a general experience of practitioners and that is best interpreted as a precursor of the law of the lever. This principle can therefore be interpreted as the missing link between the long tradition of mechanical practices and the foundation of theoretical mechanics. On the one hand, it can be traced back to experiences of practitioners. On the other hand, its application is based on the Aristotelian notion of syllogism and not yet on the proof techniques of mathematical deduction as applied to mechanical theorems by Archimedes. In this respect the treatise represents a missing link in yet another sense, namely between the rules of philosophical discourse and the rules of mathematical proofs. It is this crucial position between the first-order knowledge of practitioners and the higher-order knowledge created in Greek philosophy that explains the impact of this treatise in the European Renaissance. This is confirmed by a comparative analysis of the first early modern theories of the strength of materials. These theories were presented in the context of early modern commentaries on Aristotle’s Mechanical Problems. The Aristotelian commentators developed such theories while sharing the practical rules concerning resistance and stability that were embodied in pre-modern building methods established over centuries by architects, shipwrights and machine-makers (Matteo Valleriani). This investigation has shown how novel theorems were formulated on the basis of a process of transformation of ancient theories in view of contemporary practical activities.