In antiquity itself Neoplatonism influenced with special directness one
Western theologian, and that the most important, viz., Augustine. By the
aid of this system Augustine was freed from Manichaeism, though not
completely, as well as from scepticism. In the seventh Book of his
confessions he has acknowledged his indebtedness to the reading of
Neoplatonic writings. In the most essential doctrines, viz., those about
God, matter, the relation of God to the world, freedom and evil,
Augustine always remained dependent on Neoplatonism; but at the same
time, of all theologians in antiquity he is the one who saw most clearly
and shewed most plainly wherein Christianity and Neoplatonism are
distinguished. The best that has been written by a Father of the Church
on this subject, is contained in Chapters 9-21 of the seventh Book of
his confessions.

The question why Neoplatonism was defeated in the conflict with
Christianity, has not as yet been satisfactorily answered by historians.
Usually the question is wrongly stated. The point here is not about a
Christianity arbitrarily fashioned, but only about Catholic Christianity
and Catholic theology. This conquered Neoplatonism after it had
assimilated nearly everything it possessed. Further, we must note the
place where the victory was gained. The battle-field was the empire of
Constantine, Theodosius and Justinian. Only when we have considered
these and all other conditions, are we entitled to enquire in what
degree the specific doctrines of Christianity contributed to the
victory, and what share the organisation of the church had in it.
Undoubtedly, however, we must always give the chief prominence to the
fact that the Catholic dogmatic excluded polytheism in principle, and at
the same time found a means by which it could represent the faith of the
cultured mediated by science as identical with the faith of the
multitude resting on authority.

In the theology and philosophy of the middle ages, mysticism was the
strong opponent of rationalistic dogmatism; and, in fact, Platonism and
Neoplatonism were the sources from which in the age of the Renaissance
and in the following two centuries, empiric science developed itself in
opposition to the rationalistic dogmatism which disregarded experience.
Magic, astrology, alchemy, all of which were closely connected with
Neoplatonism, gave an effective impulse to the observation of nature
and, consequently, to natural science, and finally