Newton and Newtonianism

Abstract Isaac Newton’s famous works on mechanics, astronomy, mathematics, and optics have been widely studied in the history of physics. Over the last half century, however, historians have also come to grasp Newton’s extensive studies in fields now no longer considered scientific, such as alchemy, prophecy, and church history. Whereas earlier biographers of Newton believed they could distinguish between a young, scientific Newton and an old, non-scientific Newton, contemporary historians have shown that Newton started cultivating his wide interests well before authoring his epoch-making Principia. Newton never published a coherent account of his natural philosophy. Because of that, the relations between Newton’s different investigations were obscured to his contemporaries. Nevertheless, many were inspired by Newton. This has led previous generations of historians to describe 18th-century physics as the unfolding of ‘Newtonianism.’ Current historical research has now largely rejected that idea. Instead, recent research focuses on how Newton’s work was actually read and interpreted throughout the eighteenth century for purposes and developments that were not Newton’s own. Much eighteenth-century engagement with Newton had to do with constructing views of what proper natural philosophy was supposed to look like, and with the separation of physics and metaphysics.