Locke himself has told us how a few friends began to meet at his chamber
for the discussions of questions which soon passed into metaphysical
enquiry; and a page from a commonplace book of 1671 is the first
beginning of his systematic work. Relieved of his administrative duties
in 1675, he spent the next four years in France, mainly occupied with
medical observation. He returned to England in 1679 to assist Lord
Shaftesbury in the passionate debates upon the Exclusion Bill. Locke
followed his patron into exile, remaining abroad from 1683 until the
Revolution. Deprived of his fellowship in 1684 through the malice of
Charles II, he would have been without means of support had not
Shaftesbury bequeathed him a pension. As it was, he had no easy time.
His extradition was demanded by James II after the Monmouth rebellion;
and though he was later pardoned he refused to return to England until
William of Orange had procured his freedom. A year after his return he
made his appearance as a writer. The _Essay Concerning Human
Understanding_ and the _Two Treatises of Government_ were both published
in 1690. Five years earlier the _Letter Concerning Toleration_ was
published in its Latin dress; and four years afterwards an English
translation appeared. This last, however, perhaps on grounds of
expediency, Locke never acknowledged until his will was published; for
the time was not yet suited to such generous speculations. Locke was
thus in his fifty-eighth year when his first admitted work appeared. But
the rough attempts at the essay date from 1671, and hints towards the
_Letter on Toleration_ can be found in fragments of various dates
between the twenty-eighth and thirty-fifth years of his life. Of the
_Two Treatises_ the first seems to have been written between 1680 and
1685, the second in the last year of his Dutch exile.[1]

[Footnote 1: On the evidence for these dates see the convincing argument