Page:Popular Science Monthly Volume 66.djvu/194

190 with the grounds of belief, opinion, and assent.' How do we come by our knowledge and what are its limits? These are the problems which Locke regarded as fundamental, and with which philosophy has been largely preoccupied since his time.

Many of the difficulties which modern speculation has encountered owe their origin directly to the curious turn which Locke gave to the solution of these problems. By introspection he was led to affirm that the mind knows only its own ideas, whence subjective idealism was sure to ensue. In no case do we known things, but only ideas which somehow represent things, thought Locke. He denied the existence of innate ideas of any kind, insisting that all the mind's ideas are acquired afresh by