A review of Dr. Nock's reasons. Lots of kettle logic.

Believers in their own words
Doctor of Divinity A. D. Nock His criteria make it impossible to discover Christian borrowing from Paganism.

"Much" of what we know about the Pagan mystery religions dates from the third or forth centuries, asserts Dr. Nock expansively, pointing a finger and slurring his speech ever so little, and by then Paganism was "probably" assimilating Christian ideas.

Dr. Nock apparently doesn't need much—any—analysis to see Pagan borrowing. Borrowing is conceivable; therefore borrowing is "probable" and "obvious." QED.  Who's ready for lunch?

Much of what we know of the mysteries relates to the third and fourth centuries, and at that time some of them were probably assimilated of set purpose to Christianity in the hope of countering its attractions ; this assimilation is very obvious as part of Julian's reactionary movement in the years 362 and 363 ; but it seems to have been practiced earlier by Maximinus Daia and possibly also by Galerius.

But right away Doctor of Divinity Nock lets on that his standard for accepting Christian borrowing is just a teensy bit different. I use "teensy" here in its inter-galactic astronomical sense.

For Christian borrowing we must

	Use the greatest caution
	Demand precisely what character each belief had in the Pagan and Christian camps, to be sure they are really really really really really similar
	Be sure that the borrowed ideas were present in exactly the right time and exactly the right city—and that in exactly that time and place they had exactly the right character.
	Be sure that in exactly the right city at exactly the right time the ideas of exactly the right character were believed in with enough "intensity" (why that matters and how it's measured Doctor of Divinity Nock doesn't say).

And, says Doctor of Divinity Nock, it is impossible to know all those things!!   >>

So, according to Doctor of Divinity Nock himself, his criteria make it impossible to discover Christian borrowing from Paganism.

The greatest caution must therefore be exercised in determining what was the precise character of any particular mystery which might be supposed to have influenced [pg 59] Christianity in the first century ; we need in effect to know its character at the point of contact, since it is unsafe to assume that there would be complete uniformity in any such cult wherever practiced (we know that later this was certainly not so with Mithraism, which varied in details from East to West). Further, we require some means of estimating not merely in what cities a particular mystery was observed, but what the local intensity was, whether it was for instance impossible for any man in those parts to be unaware of its more characteristic features, or at any rate of its existence. To all these questions there cannot be complete and satisfactory answers
[Nock, Arthur Darby. Early Gentile Christianity and Its Hellenistic Background ((1928 / 1964)), pg. 58- 9]

.

	Pagan borrowing obvious Christian borrowing impossible

Doctor of Divinity Nock's analysis uses different criteria to identify Pagan and Christian borrowing. Pagan borrowing that is conceivable is "obvious." Christian borrowing is always—always!—excluded by Doctor of Divinity Nock's analysis.

We've been sitting in a wagon with no wheels. When your analysis makes it impossible to discover borrowing, and then you don't discover borrowing, the only real information in that "no borrowing" result is that your analysis was designed not to work. When you sit is a wagon with no wheels, you always go nowhere.

Doctor of Divinity Nock's analysis fails because it is designed to make Christian borrowing impossible.

Remember, I'm not telling you about Doctor of Divinity Nock because I think his analysis is weak. I'm showing you what he wrote because on the subject of Christian borrowing from Paganism, Doctor of Divinity Nock is the most famous, most admired, most cited, most quoted anti-borrowing scholar there is. And this book, Early Gentile Christianity and its Hellenistic Background is the most famous, most admired, most cited, most quoted anti-borrowing book anybody anywhere ever wrote on the subject.