Abstract
In book two, Chapter eight of the essay, Locke claims that primary qualities, Unlike secondary qualities, Are really in objects and are resemblances of our ideas. The idioms of containment and of resemblance are explained as formulations of what jonathan bennett calls the analytic thesis and the causal thesis. It is argued that locke was concerned to distinguish primary qualities from what he calls secondary qualities because he thought the latter were not really qualities at all but mere powers and hence not genuinely explanatory