Alciphron (1734) was written while Berkeley was in Rhode Island, and is a philosophical defense of Christian doctrine. It also contains some additional comments on perception, supplementing earlier work on that topic. The Analyst (1734) contains trenchant criticism of the method of fluxions in differential calculus, and it set off a flurry of pamphlet replies to Berkeley’s criticisms, to which Berkeley responded in his A Defense of Free Thinking in Mathematics. Siris (1744) contains a detailed account of the medicinal values of tar-water, water boiled with the bark of certain trees. This book also contains a defense of a sort of corpuscularian philosophy that seems to be at odds with the idealism elaborated in the earlier works for which Berkeley is now famous.
In the years 1707–08, the youthful Berkeley kept a series of notebooks in which he worked out his ideas in philosophy and mathematics. These books, now known as the Philosophical Commentaries, provide the student of Berkeley with the rare opportunity to see a great philosopher’s thought in development.
See also HUME, IDEALISM, LOCKE, PERCEP- TION , PHENOMENALIS. G.S.P.