Abstract

Berkeley's Siris may be an unduly neglected treatise. Yet it reveals and confirms its author's philosophical ambitions and achievements. The greatest of them is his theory of causality. Berkeley tries to show that agents can influence the world by using ethereal corpuscles as their instruments. These particles are both material but also in some sense immaterial or occult because they both follow and do not follow the laws of nature. Siris is a rhetorical text which uses analogy, metaphor, paradox, and ambiguity to illuminate the reader. I argue that the universe in Siris is ambiguous with respect to its material and immaterial essence. The world is at the same time scientific and material and metaphysical and immaterial. Berkeley fights against scientific mechanistic materialism when he subordinates science to God's will. I try to clarify how ambiguity works for Berkeley the metaphysician in establishing the superiority of minds or agents over matter and mechamisms.