he organized here a literary club similar to the one he had formed at Lord Ashley's. Le Clere, with whom he had formed an intimacy, was at this time publishing a literary and scientific review, the “Bibliothèque Universelle,” and to this Locke became a contributor. The year of his return to England, the first “Letter on Toleration” was published anonymously in Holland. This letter, as well as the three that followed, expressed a broader principle than the world was yet ready to accept. Locke tolerated all beliefs but atheism, which, he held, struck at morality, and Roman Catholicism, which was in itself intolerant of others. Though he spent his life in the Church of England, it is evident from his writings that he considered her doctrines narrow.
The “Essay concerning the Human Understanding” was published in 1690, soon after Locke's return to England. He received thirty pounds for the copyright, not a large sum for a work that had been more than eighteen years in preparation and was destined to be one of the greatest influences in the establishment of modern philosophy. Sir James Mackintosh says of the Essay: “Few books have contributed more to rectify prejudice, to undermine established errors, to diffuse a just mode of thinking, to excite a fearless spirit of inquiry, and yet to contain it within the boundaries which Nature has prescribed to the human understanding.”
Locke's aim in the Essay is to discover how people acquire knowledge and develop thought. He rejects the theory of innate ideas and likens the mind to a blank sheet of paper. All thought, he concludes, is the result of sensation, or the operations of the external
