Locke's emphasis on the role of experience in the formation of the mind and his concern with false associations of ideas has led many to characterise his theory of mind as passive rather than active, but as Nicholas Jolley, in his introduction to Locke's philosophical theory, points out, this is "one of the most curious misconceptions about Locke." As both he and Tarcov highlight, Locke's writings are full of directives to seek out knowledge actively and reflect on received opinion; in fact, this was the essence of Locke's challenge to innatism.