The crucial parts of knowing locke for reading berkeley are few the sense are perceiver dependent external objects are perceiver independent primary/secondary quality distinction substance and the substances material. Berkeley will dispute locke"s four points here of the external world epistemology dialogues p. 9 dialogue begins with hylas telling philonous on a previous conversation the night before. Philonous was the topic of conversation because he is a sceptic. The issue is of material substance and because philonous denies such a thing he is a shown to be a lacking in common sense and being a sceptic. Philonous is going to enquire from hylas by what he means of scepticism. The answer that gives is the general answer. (prof"s pet peeve: 1. it should be people for who not and things for that. ) Philonous is going to eventually show that eh doesn"t doubt everything. In fact he"s going to take a poisition that is sceptic resistant.