An Aristotelian and Cartesian Walk into a Physics Theatre: The Story of Senguerd and de Volder

Tammy Nyden

Grimell College, USA

We all know the story, that of Scholastics stubbornly clinging to their Aristotelian assumption that the world is as it appears, of taking scientia to be a matter of explaining why it is such by describing its causes. We all know another story, that of Cartesians asserting that the senses do not tell us what the world is really like and taking scientia to be a project of deducing phenomena from first principles. Neither of these stories made room for experiment. In the first case, experiment was not needed since the world, as it is, was taken to be known immediately through the senses. There was no need to trick nature into telling us its secrets, for it had none. In the second case, experiment was problematic as a source of knowledge, for being based on sensory input, it is prone to error and prejudice. While it may provide practical information for living day-to-day, sensory knowledge could not produce scientia. But then one day an Aristotelian and a Cartesian walk into a Physics Theatre – and what do they do – they change the way university physics is taught by integrating into their lectures the demonstration of experiments. How are we to make sense of this story, the story of the University of Leiden from 1675 to 1705, when the Aristotelian Wolferd Senguerd and the Cartesian Burchard de Volder shared the Physics Theatre and key elements of pedagogy? This paper will tell their story. It will compare and contrast both their pedagogies of experiment and the role experiment plays in their philosophies of science. In doing so it will show that terms like Aristotelian and Cartesian are often more political than descriptive. The story of Senguerd and de Volder is more consistent with a reformation view of scientific change, one in which elements of the old and new are mixed together in various ways to yield slow and steady scientific change. Their story shows that there were many views along the way of what scientia could be, not a revolutionary gestalt switch.