litico-economic questions Locke contributed the two _Treatises on
Government_, 1690, and three essays on money and the coinage. In the year
1689 appeared the first of three _Letters on Tolerance_, followed, in 1693,
by _Some Thoughts on Education_, and, in 1695, by _The Reasonableness of
Christianity as delivered in the Scriptures_. The collected works appeared
for the first time in 1714, and in nine volumes in 1853; the philosophical
works (edited by St. John) are given in Bonn's Standard Library
(1867-68).[1]

[Footnote 1: Lord King and Fox Bourne have written on Locke's life, 1829
and 1876. A comparison of Locke's theory of knowledge with Leibnitz's
critique was published by Hartenstein in 1865, and one by Von Benoit (prize
dissertation) in 1869, and an exposition of his theory of substance by De
Fries in 1879. Victor Cousin's _Philosophie de Locke_ has passed through
six editions. [Among more recent English discussions reference may be made
to Green's Introduction to Hume's _Treatise on Human Nature_, 1874 (new ed.
1890), which is a valuable critique of the line of development, Locke,
Berkeley, Hume; Fowler's _Locke_, in the English Men of Letters, 1880; and
Fraser's _Locke_, in Blackwood's Philosophical Classics, 1890.--TR.]]

%(a) Theory of Knowledge.%--Locke's theory of knowledge is controlled by
two tendencies, one native, furnished by the Baconian empiricism, and the
other Continental, supplied by the Cartesian question concerning the origin
of ideas. Bacon had demanded the closest connection with experience as
the condition of fruitful inquiry. Locke supports this commendation of
experience by a detailed description of the services which it renders to
cognition, namely, by showing that, in simple ideas, perception supplies
the material for complex ideas, and for all the cognitive work of the
understanding. Descartes had divided ideas, according to their origin, into
three classes: those which are self-formed, those which come from without,
and those which are innate (p. 79), and had called this third class the
most valuable. Locke disputes the existence of ideas in the understanding
from birth, and makes it receive the elements of knowledge from the senses,
that is, from without. He is a representative of sensationalism,--not in
the stricter sense, first put into the term by those who subsequently
continued his endeavors, that thought arises from perception, that it is
transformed sensation--but in the wider se