Abstract

In A Treatise of Artificial Magnets, John Michell observes, Not being aware of this property [i.e. the equality of attraction and repulsion], he [Gilbert] concluded from some experiments he had made, not very irationally [sic], that the Needle was not attracted by the magnet, but turned into its position by, what he calls, a disponent virtue […]. For Michell, the disponent virtue 1 is the underlying cause of magnetic phenomena in Gilbert’s treatment. He is not alone. Ridley and Carpenter also read Gilbert’s magnetism as positing a disponent virtue.2 I agree. In this paper, I show what it would entail to treat Gilbertian magnetism as...