Thus the conclusion is, to say the least, precarious. It is by no means so easy as is sometimes supposed to prove that a pagan usage attested only long after the time of Paul is really the source of Pauline teaching. And it will not help to say that although there is no direct dependence one way or the other yet the pagan and the Pauline teaching have a common source. For to say that a usage has a pagan source several centuries earlier than the time at which the usage is first attested is really to assume the point that is to be proved. We are not here dealing with a question of literary dependence, where the unity of the books which are being compared is assumed. In such a question the independence of the two writers may be proved by the general comparison of the books; it may be shown, in other words, that if one author had used the other author's work at all he would have had to use it a great deal more than as a matter of fact the similarity would indicate. In such cases, striking verbal similarity in one place may prove that both books were dependent upon a common source. But if a pagan usage of the fourth century is similar to a Christian usage, the fact that in general the paganism of the fourth century is independent of Christianity does not disprove dependence of paganism upon Christianity at this one point.
It is not surprising, therefore, that the reasoning just outlined is usually supplemented by a further consideration. It is maintained, namely, that the mystic piety of paganism forms to some extent a unit; it was not a mere fortuitous collection of beliefs and practices, but was like an enveloping spiritual atmosphere of which, despite variations of humidity and temperature, the fundamental composition was everywhere the same. If, therefore, the presence of this atmosphere of mystical piety can be established here and there in sources of actually pre-Christian date, the investigator has a right to determine the nature of the atmosphere in detail by drawing upon later sources. In other words, the mystical religion of the Hellenistic age is reconstructed in detail by the use of post-Christian sources, and then (the essential unity of the phenomenon being assumed) the early date of this oriental mystical religion is established by the scanty references in pre-Christian times. It is admitted, perhaps, that the elements of oriental mysticism actually found in pre-Christian sources would not be sufficient to prove dependence of Paul upon that type of religion; but the elements found in later sources are thought to be so closely allied to those which happen to have early attestation that they too must be supposed to have been present in the early period, and since they are similar to Paulinism they must have exerted a formative influence upon Paul's religion. To put the matter briefly, the nature of Hellenized oriental religion is established by post-Pauline sources; whereas the early origin of that religion is established by the scanty pre-Christian references.
This procedure constitutes a curious reversal of the procedure which is applied by the very same scholars to Christianity. Christianity is supposed to have undergone kaleidoscopic changes in the course of a few years or even months, changes involving a transformation of its inmost nature; yet pagan religion is apparently thought to have remained from age to age the same. When Paul, only a few years after the origin of the Church, says that he "received" certain fundamental elements in his religion, the intimate connection of those elements with the rest of the Pauline system is not allowed to establish the early origin of the whole; yet the paganism of the third and fourth centuries is thought to have constituted such a unity that the presence of certain elements of it in the pre-Christian period is regarded as permitting the whole system to be transplanted bodily to that early time.
Of course, the hypothesis which is now being examined is held in many forms, and is being advocated with varying degrees of caution. Some of its advocates might defend themselves against the charge of transplanting post-Christian paganism bodily into the pre-Christian period. They might point to special evidence with regard to many details. Such evidence would have to be examined in any complete investigation. But the objection just raised, despite possible answers to it in detail, is not without validity. It remains true, despite all reservations, that adherents of the "comparative-religion school" are entirely too impatient with regard to questions of priority. They are indeed very severe upon those who raise such questions. They do not like having the flow of their thought checked by so homely a thing as a date. But dates sometimes have their importance. For example, the phrase, "reborn for eternity," occurs in connection with the blood-bath of the taurobolium. How significant, it might be said, is this connection of regeneration with the shedding of blood! How useful as establishing the pagan origin of the Christian idea! From the confident way in which the phrase "reborn for eternity" is quoted in discussions of the origin of Christianity, one would think that its pre-Christian origin were established beyond peradventure. It may come as a shock, therefore, to readers of recent discussions to be told that as a matter of fact the phrase does not appear until the fourth century, when Christianity was taking its place as the established religion of the Roman world. If there is any dependence, it is certainly dependence of the taurobolium upon Christianity, and not of Christianity upon the taurobolium.
The same lordly disregard of dates runs all through the modern treatment of the history of religion in the New Testament period. It is particularly unfortunate in popular expositions. When the lay reader is overwhelmed by an imposing array of citations from Apuleius and from Lucian, to say nothing of Firmicus Maternus and fourth-century inscriptions, and when these late citations are confidently treated by men of undoubted learning as witnesses to pre-Christian religion, and when the procedure is rendered more plausible by occasional references to pre-Christian writers which if looked up would be found to prove nothing at all, and when there is a careful avoidance of anything like temporal arrangement of the material, but citations derived from all countries and all ages are brought together for the reconstruction of the environment of Paul—under such treatment the lay reader often receives the impression that something very important is being proved. The impression would be corrected by the mere introduction of a few dates, especially in view of the fact that oriental religion undoubtedly entered upon a remarkable expansion shortly after the close of the New Testament period, so that conditions prevailing after that expansion are by no means necessarily to be regarded as having existed before the expansion took place.
This criticism is here intended to be taken only in a provisional way. The justice of it can be tested only by a detailed examination of the hypothesis against which the criticism is directed.
How, then, is the pre-Christian mystical religion of the Hellenistic world to be reconstructed? What sources are to be used? Some of the sources have already been touched upon in the review of the individual oriental cults. And incidentally the unsatisfactory character of some of these sources has already appeared. But it is now necessary to examine other sources which are not so definitely connected with any clearly defined cult.
Increasing attention has been paid in recent years to the complex of writings which goes under the name of Hermes Trismegistus. These Hermetic writings embrace not only a corpus of some fourteen tractates which has been preserved in continuous Greek manuscript form, but also fragments contained in the works of Stobæus and other writers, and finally the "Asclepius" attributed to Apuleius. It is not usually maintained that the Hermetic literature was completed before about 300 A.D.; no one claims anything like pre-Christian origin for the whole. The individual elements of the literature—for example, the individual tractates of the Hermetic corpus—are usually regarded as having been produced at various times; but no one of them is generally thought to have been written before the beginning of the Christian era. With regard to the most important tractate, the "Poimandres," which stands at the beginning of the corpus, opinions differ somewhat. J. Kroll, for example, the author of the leading monograph on the Hermetic writings, regards the Poimandres as the latest of the tractates in the corpus, and as having appeared not before the time of Numenius (second half of the second century);[158] whereas Zielinski regards it as the earliest writing of the corpus.[159] By an ingenious argument, Reitzenstein attempts to prove that the Christian "Shepherd of Hermes" (middle of the second century) is dependent upon an original form of the "Poimandres."[160] But his argument has not obtained any general consent. It is impossible to push the material of the Poimandres back into the first century—certainly impossible by any treatment of literary relationships.
With regard to the origin of the ideas in the Hermetic writings, there is considerable difference of opinion. Reitzenstein allows a large place to Egyptian and Persian elements; other scholars emphasize rather the influence of Greek philosophy, which of course is in turn thought to have been modified by its contact with oriental religion. J. Kroll,[161] W. Kroll,[162] Reitzenstein,[163] and others deny emphatically the presence of any considerable Christian influence in Hermes; but at this point Heinrici, after particularly careful researches, differs from the customary view.[164] Windisch is enough impressed by Heinrici's arguments to confess that Christian literature may have influenced the present form of the Hermetic writings here and there, but insists that the Christian influence upon Hermes is altogether trifling compared to the influence upon primitive Christianity of the type of religion of which Hermes is an example.[165] The true state of the case, according to Windisch, is probably that Christianity first received from oriental religion the fundamental ideas, and then gave back to oriental religion as represented by Hermes certain forms of expression in which those ideas had been clothed. At the same time Windisch urges careful attention to Heinrici's argument for Christian influence upon Hermes for three reasons: (1) all Hermetic writings are later than the New Testament period, (2) the Hermetic writings are admittedly influenced by Judaism, (3) at least the latest stratum in the Hermetic writings has admittedly passed through the Christian sphere. These admissions, coming from one who is very friendly to the modern method of comparative religion, are significant. When even Windisch admits that the form of expression with regard to the new birth in the Poimandres may possibly be influenced by the Gospel tradition, and that the author of the fourth Hermetic tractate, for example, was somewhat familiar with New Testament writings or Christian ideas and "assimilated Christian terminology to his gnosis," and that the term "faith" has possibly come into Hermes (iv and ix) from Christian tradition—in the light of these admissions it may appear how very precarious is the employment of Hermes Trismegistus as a witness to pre-Christian paganism.