The ArgumentThe claim that Jan Swammerdam's empirical research did not support his theory of biological preformation is shown to rest on a notion of evidence narrower than that used by many seventeenth-century natural philosophers. The principles of evidence behind the use of mechanical models are developed. It is then shown that the Cartesian theory of biological reproduction and embryology failed to gain acceptance because it did not meet the evidential requirements of these principles. The problems in this and other mechanistic (...) theories prior to Swammerdam are found to arise from certain difficulties and tensions in the mechanical conception of nature, which Swammerdam's theory is able to resolve. The relation between Swammerdam's empirical research and his theory is examined and shown to satisfy the required notion of evidence.Leibniz' puzzling appeals to Swammerdam's research in support of his metaphysical doctrine of the spontaneous development of individual substances are then examined and shown to fall within the parameters of the notion of evidence. (shrink)

Summary Robert Boyle did not subordinate chemistry to mechanical philosophy. He was in fact reluctant to explain chemical phenomena by having recourse to the mechanical properties of particles. For him chemistry provided a primary way of penetrating into nature. In his chemical works he employed corpuscles endowed with chemical properties as his explanans. Boyle's chemistry was corpuscular, rather than mechanical. As Boyle's views of seminal principles show, his corpuscular philosophy cannot be described as a purely mechanical theory of matter. Boyle's (...) classification of corpuscles allowed him to connect his corpuscular views of matter with chemistry. Boyle did not rule out the possibility of a classification of chemical substances based on their properties: his aim was to reform the received classification. (shrink)