Clement, in part of his Stromata, and in his Cohortatio, has expressed the spirit of his apologetic; which resembles those of the first group, in admitting the value of heathen philosophy as a preparation for Christianity, and claims that the Hebrews are the source of philosophy, and that Christianity is the full satisfaction for those who sought knowledge.
The spirit and details of Origen's defence have been so fully given in Lecture [II]. and Note [14], that it is unnecessary to enlarge upon the subject. His apology marks a further step. Tertullian replied to the prejudices of the vulgar, and M. Felix to the scepticism of the educated, which formed two elements in the heathen reaction of the second century. Origen furnished the reply to the attack made by the heathen philosophy. It is in reply to Celsus, who possessed a competent knowledge of Christianity; and who, though writing earlier than the time when the charges which Tertullian afterwards refuted were common, was too well informed to have believed them, and opposed Christianity on deeper grounds. Celsus stands later logically, though not chronologically, than the authors of those frivolous charges, and midway between them and the educated assailants of Christianity of the third century, such as Porphyry. Origen's defence too marks a similar advance, and, by exhibiting sympathy with the very philosophy which Porphyry and others adopted, shows the kind of defence which was thought likely to attract philosophic minds.
The chronology compels us to return to the African church, and introduces us to two Apologists;—Arnobius and Lactantius; one of whom seems to have written a little before Christianity had become a tolerated religion; the latter a little afterwards.
The work of Arnobius is taken up, partly in repelling charges made against the Christians, such as that the Christians do not worship, which are no longer charges of the absurd kind made a century before, partly in comparing Christianity and heathenism; and partly in offering the evidence for Christianity. It is in this point that we find the peculiarity which belongs to Arnobius. He is the first writer who lays firm stress on the demonstrative character of the evidence of fact. In previous writers Christianity had been proved by probability: he makes it to rest on the evidence of certainty; and considers the fact of the revelation to guarantee the contents of it.
The large work of Lactantius, the Institutiones Divinæ, is a work of ethics as well as of defence. Christians have obtained protection, and defence is becoming didactic: apology is expiring in instruction: all that is now needed for the spread of Christianity is, that its nature should be understood. The work is partly a work of religion, partly of philosophy, partly of ethics; the object in each case being to show that Christianity supplies the only true form in each department of thought.
The remaining Apologists may be grouped together, though they have no point of union, except that their arguments are directed to the special condition of heathenism; when, being no longer triumphant, it was standing on the defensive, and, at the time of the two latter of the group, was fast declining. They are, Eusebius, Cyril of Alexandria, and Augustin.
If Origen is the metaphysical philosopher of the early Apologists; if Augustin is the political; Eusebius is the man of erudition. He has left, besides the small work against Hierocles (see Note [17]), two works of defence; the first the Evangelica Præparatio, against the Gentiles; the second the Evangelica Demonstratio, more suited for the Jews. The former work is to show that Christianity has not been accepted without just cause; which he attempts to prove by a very elaborate discussion (valuable to us in a literary point of view, on account of the quotations which he has preserved) of the various religions, Egyptian, Phœnician, Greek, and of the various types of Greek thought and belief; and, by a comparison of them with the Hebrew, he shows the superiority of the last. The other work, the Evangelica Demonstratio, is designed to prove that Christ and Christianity fulfil the ancient prophecies. His apology marks the transitionary time when Christianity was becoming the religion of the Roman world, and men hesitated as to its truth, looking back with regret to the past, with uneasiness to the future.
The other two Apologists are nearly a century later; when Christianity had been long established.