アダム・スミスの「天文学史」におけるデカルト批判の再検討

─ ニュートン革命前夜における渦動仮説とその科学史的意義

抄録

Adam Smith often criticized Cartesian philosophy; nevertheless, in History of Astronomy, he also offered a qualified positive assessment of Descartes’ vortex hypothesis. This point has been overlooked, partly because Smith is often regarded as a conventional Newtonian philosopher. Accordingly, this paper proposes a new interpretation of Smith’s Newtonianism. It challenges the traditional view by highlighting Smith’s implicit positive assessment of Descartes. The main argument of this paper is that Smith assessed Descartes’ vortex hypothesis as playing a significant role in generalizing a coherent framework for understanding both the rapid motions of the Earth and other planets and their supposed natural inertness. These issues had become especially pronounced after the Copernican revolution. Smith, therefore, credits the vortex hypothesis with helping to reduce contemporary astronomical prejudices. Smith further implies that the incompleteness of Descartes’ metaphysical hypothesis unintentionally opened the way for later scientific development. It helped prepare the intellectual setting that allowed Newton to build his system. Newton’s system was grounded in experiment and observation. It was also based on Kepler’s laws, as confirmed by Cassini’s observations. When Smith wrote History of Astronomy, Descartes’ vortex hypothesis had already been rejected. But Newton’s astronomy arose in an intellectual environment shaped by the Cartesian philosophical framework that Smith himself elsewhere criticized.