Christian Thomasius may be taken as a leading exponent of the theory
that religious liberty logically follows from a right conception of law.
He laid down in a series of pamphlets (1693–1697) that the prince, who
alone has the power of coercion, has no right to interfere in spiritual
matters, while the clergy step beyond their province if they interfere
in secular matters or defend their faith by any other means than
teaching. But the secular power has no legal right to coerce heretics
unless heresy is a crime. And heresy is not a crime, but an error; for
it is not a matter of will. Thomasius, moreover, urges the view that the
public welfare has nothing to gain from unity of faith, that it makes no

[120] difference what faith a man professes so long as he is loyal to
the State. His toleration indeed is not complete. He was much influenced
by the writings of his contemporary Locke, and he excepts from the
benefit of toleration the same classes which Locke excepted.

Besides the influence of the jurists, we may note that the Pietistic
movement—a reaction of religious enthusiasm against the formal theology
of the Lutheran divines—was animated by a spirit favourable to
toleration; and that the cause was promoted by the leading men of
letters, especially by Lessing, in the second half of the eighteenth
century.

But perhaps the most important fact of all in hastening the realization
of religious liberty in Germany was the accession of a rationalist to
the throne of Prussia, in the person of Frederick the Great. A few
months after his accession (1740) he wrote in the margin of a State
paper, in which a question of religious policy occurred, that every one
should be allowed to get to heaven in his own way. His view that
morality was independent of religion and therefore compatible with all