George Berkeley (1685-1753) held that matter does not exist, and that the sensations we take to be caused by an indifferent and independent world are instead caused directly by God. Nature has no existence apart from the spirits who transmit and receive it. In this book, Winkler presents these conclusions as natural (though by no means inevitable) consequences of Berkeley's reflections on such topics as representation, abstraction, necessary truth, and cause and effect. He offers new interpretations of Berkeley's views on unperceived objects, corpuscularian science, and our knowledge of God and other minds.