published his famous _Essay on the Human Understanding_ in 1690, and it
had taken several years for the opposition to his views, and in
particular to his theological toleration, to take effect. But in 1697
there were made a number of almost simultaneous attacks on Locke's
position. The circle at Salisbury was involved in them, for one of these
was written by Norris of Bemerton, and another is attributed to a member
of the Burnet family. Catharine Trotter, who had studied Locke's later
works with enthusiastic approval, was scandalised by the attacks, and
sat down to refute them. This must have been in 1701.

Although the intellectual society of Salisbury was prominent in taking
the conservative view of Locke, our bluestocking could not refrain from
telling Mrs. Burnet what she had done, nor from showing her treatise to
that friend under vows of confidence. But Mrs. Burnet, who was impulsive
and generous, could not keep the secret; she spoke about it to the
Bishop, and then to Norris of Bemerton, and finally (in June 1702) to
Locke himself. Locke was at Oates, confined by his asthma; he was old
and suffering, but still full of benevolence and curiosity, and he was
graciously interested in his remarkable defender at Salisbury. As he
could not himself travel, he sent his adopted son to call on Catharine
Trotter, with a present of books; this was Peter King, still a young
man, but already M.P. for Beer Alston, and later to become Lord
Chancellor and the first Lord King of Ockham. George Burnet, writing
from Paris, had been very insistent that Catharine should not publish
her treatise, but she overruled his objections, and her _Defence of Mr.
Locke's Essay on the Human Understanding_ appeared anonymously in May
1702. People were wonderfully polite in those days, and Locke himself
wrote to his "protectress" a charming letter in which he told her that
her "_Defence_ was the greatest honour my Essay could have procured me."