 How and when Bruno began to develop what he called his “new philosophy” is uncertain (Granada 1990). His earliest surviving philosophical work, On the Shadows of the Ideas, dated 1582, hints at a few of its propositions, including heliocentricism (BOL II.1, 7–8). The first detailed statement, however, came in The Ash Wednesday Supper, published at London in 1584, in which he set out his interpretation of Copernicus’s heliocentric hypothesis, as explained in On the Revolutions (1543). Dismissing contemporary claims that Copernicus’s hypothesis was merely a convenient computational device, Bruno announced that it disproved the traditional Aristotelian-Ptolemaic picture of the cosmos. In the first place, it disproved Aristotle’s doctrine that each sublunary element had a fixed “natural place” at the centre of the cosmos—the earth’s globe at the very centre, water in the sphere immediately surrounding it, followed by the air and fire spheres—and that particles of the elements, if displaced from these natural spheres, had an intrinsic impulse to regain them. On the contrary, since the earth, Bruno explained, was a planet circling the sun, the elemental spheres of which it was constituted were continuously in motion. The elements did not have absolute “natural places”; and an elemental part, whether displaced from a whole or chancing to be near a whole, sought to attach itself to it because a whole was the place where it would be best preserved. Once united with a whole, elemental parts were no longer heavy or light and revolved with it naturally, that is, without resistance. This doctrine of gravity drew on Ficino’s Neoplatonic ideas of elemental motion, Copernicus’s doctrine of gravity, Lucretius’s comments on the weightlessness of parts in their wholes and scholastic notions of self-conservation (Knox 2002).