On the list of thinkers who have exemplified what Brand Blanshard called the "rational temper," John Locke must surely place very high. The reader of this his most influential and important work will be constantly struck not only by his sane and sober approach to philosophical questions but indeed by how commonplace his own proposed solutions have become. It will be found that Locke, generally regarded as an "empiricist," is extremely hard to pigeonhole. Though rejecting (an earlier version of) the doctrine of "innate ideas" and insisting that all of our ideas come from or through sense-experience, he was clearly a "rationalist" as regards the nature of knowledge itself. Both modern empiricists and modern rationalists could benefit from a healthy infusion of his reasonable, even-handed tenor and uncommon common sense. This is quintessential reading, for everyone interested in the formation of the modern self.