Brand Blanshard was an American philosopher whose task is best described in his own words as the "vindication of reason against recent philosophical attacks." Blanshard was thus a critic—a critic of all those who, he alleged, reject rationality—but at the same time he tried to exhibit the credentials that reason can show in its own right.

Blanshard was educated at the University of Michigan, Columbia, Oxford, and Harvard—where he received his PhD. He taught at the University of Michigan, at Swarthmore College, and at Yale—where he was Sterling professor of philosophy and chairman of the department. The multitude of honors he received during his career precludes their enumeration here.

Blanshard's first major work was The Nature of Thought (London, 1939), in two volumes, each divided into two books. The first volume is largely concerned with a subject matter common to both...