In the later middle ages, however, philosophy gradually succeeded in
emancipating itself so entirely from theology, that when the Renaissance
came, and a large body of heathen thought was introduced into the current
of European life by means of ancient literature, a third crisis occurred.
The independence passed into open revolt, and, fostered by political
confusion and material luxury, expressed itself in a literature of
unbelief.

The mental awakening which had commenced in art and extended to literature
paved the way for a spiritual awakening. The Reformation itself, though
the product of a deep consciousness of spiritual need, an emancipation of
soul as well as mind, is nevertheless a special instance of the same
dissolution of mediaeval life, and must therefore be regarded as belonging
to the same general movement of free thought, though not to that sceptical
form of it which comes within the field of our investigation. For
Protestantism, though it be scepticism in respect of the authority of the
traditional teaching of the Church, yet reposes implicitly on an outward
authority revealed in the sacred books of holy Scripture, and restricts
the exercise of freedom within the limits prescribed by this authority;
whereas scepticism proper is an insurrection against the outward authority
or truth of the inspired books, and reposes on the unrevealed, either on
consciousness or on science. The one is analogous to a school of art which
desires to reform itself by the use of ancient models; the other to one
which professes to return to an unassisted study of nature. The spiritual
earnestness which characterized the Reformation prevented the changes in
religious belief from developing into scepticism proper; and the theology
of the Reformation is accordingly an example of defence and reconstruction
as well as of revulsion.

During the century which followed, mental activity found employment in
other channels in connexion with the political struggles which resulted
from the religious changes. But the seventeenth age was another of those
epochs which form crises in the history of the human mind. The
reconstruction at that time of the methods on which science depends, by
Bacon from the empirical side, by Descartes from the intellectual, created
as great a revolution in knowledge as the Renaissance had produced in
literature or the Reformation in religion; and a body of materials was
presented from which philosophers ventured