Maybe there was some kind of co-regency involved (unlikely for Neriglissar unless Nebuchadnezzar lived more than 80 years). Maybe he meant 'months' instead of 'years' for these two rulers. Maybe he was on drugs. Maybe he was just wrong. Whatever the case, it does not help the Society's case whether Josephus is right here or not. Given that records exist for all of the known years, and none for the missing years it is not likely that Josephus is correct in his assignment of these reigns.
I absolutely agree with you, Jeffro. Something is definitely wrong. But with all those possibilities of what is really going on with Josephus, was he on drugs, or just what was happening, you have to take into consideration another possibility, and that is that he was doing the usual Jewish thing, which was tripping up the gentiles. Remember even Jesus said that he spoke in riddles so that outsiders would not know what he was up to. I can demonstrate this with Josephus elsewhere, but can't blame anyone for dismissing him. Thus I will just note for the record, that Josephus somewhere came up with 18 years for Evil-Merodach, which by other chronology is the correct number.
But here's the "cryptic" theory for the 40 years to "consider." As I mentioned before when the reign of Nebuchadnezzar was reduced 2 years to 43 years vs 45 years, they also tried to squeeze some of the events together so that what happened in the accession year plus year 1 of Nebuchadnezzar now happens in his accession year. As a result the events during the reign of Nebuchadnezzar from that time happen a year earlier than in the Bible. Some have concluded this is just a double system of counting the rulerships but this is not the case. Thus you have Josephus in some places claiming Jerusalem falls in the 18th year of Nebuchadnezzar and others in the 19th.
We can go "cryptic" because usually the cryptic reference is a clue to the true reference. Thus "forty" is related to "four", an acknowledgement that Josephus clearly understands that in no way did Niglassar rule for 40 years but should be confirmed at 4 years.
What you do now is take that 40 and compare it with other numbers and see if there is any relevance.
In this case, where Jerusalem falls in year 19, there are 74 years until the return of the Jews. If the destruction is artificially moved back to year 18, then there are 75 years until the 1st of Cyrus. That is the number you get when you add up 18 years for Evil-Merodach, "40 years" for Niglassar, and 17 years for Nabonidus. 18+40+17=75
Now this is far-fetched for some, but since we have Josephus on drugs, crazy, or just plain wrong, you have to wonder if he wasn't making a cryptic reference to "75" by using 40 years for Niglassar, something certainly that would be considered completely "crazy" when read.
And that goes to the foundation of how Josephus worked it. You see, if you openly contradict the powers to be, then they will shut you down and suppress you and destroy you. You won't get published. Knowledge and information stops. But if you appear to be "crazy" then they will let you babble on publicly and you will be ignored. Thus the "forty" is a decoy so he could publish the 18. By saying something ridiculous, next to critical information, the truth is disregarded but it still gets published.
But this is very Jewish. For instance, the so-called "Rabinnical Time Line" relating to key temple dates does the same thing. The temple is dated to the 6th year of Darius to 352 BCE. Now this otherwise is 7th year of Artaxerxes II, a time when Alexander the Great is about to come onto the scene and well-documented Greek chronology. Artistotle is already 32 years old! And yet they claim this is the sixth of Darius! It's preposterous and ridiculous! But that's the key! It is so ridiculous that no one pays attention to that timeline. But in reality, we can't dismiss it as a "key" to the original timeline. Why? Because the fake date for the 1st of Cyrus in 537BCE is 82 years askew. The original date is 455BCE. Likewise the date the temple was completed is also 82 years off, 516BCE (fake) vs 434BCE. 352BCE, the year of the 6th of Darius in the rabbinical timeline is exactly 82 years after 434BCE, the true date. So you see, it's a hidden clue that they knew the correct date, and they are mocking the revised chronology by creating a timeline 82 years off in the other direction. Coincidence?
Let's say it is. But then you have the 422BCE and 426BCE dates associated with the temple being destroyed. Clearly the 4-year gap from the fall of Jerusalem and the beginning o the 70 years would be related to these dates 4 years apart. The original dates are 529BCE and 525BCE for the fall of Jerusalem and the last deportation. So are these years also 82 years off? No. But another interval gets you these dates. That is, there are 21 years from 434BCE to 455BCE, when the second temple was begun. If you add 21 years to 82 years you get 103 years. If you add 103 years to 422BCE and 426BCE you get 525BCE and 529BCE.
Finally, the beginning of the first temple is correctly dated to 906BCE. There are 74 years from the end of the first temple to the beginning of the second. The rabbinical dating for the 1st temple is 832BCE. Add 74 to 832 and you get 906BCE. Thus you have a situation of not being able to dismiss the rabinnical timeline since while the dating is totally ridiculous, too ridiculous to be believed even by Jews, they convert rather empirically by using prime temple date intervals and differences in the faked chronology and the true chronology. It's the game of "hiding in plain sight." But it is ingenious as well since true information gets to be transmitted "in plain sight" of those who know better. You just have to appear totally unbelievable and ridiculous and you can publish what you want, no one will suppress you because you will be considered a fool and not taken seriously. In the meantime, you are transferring secret information. Of course, there would be no need for this deception and duplicity if there were no revisions. But this is very Jewish even Biblical! Even the Biblle convolutes its own chronology likely to make it too difficult to revise easily. It gives seemingly parallel accounts that seem to have some contradictions when compared but really hide technical detail.
Therefore, because this has been observed as a presumed tactic so that secret information can be transferred, and 75 is relevant to the chronology, Josephus has to be considered possibly providing cryptic information by the absolutely ridiculdous and easily disproven "40 year" rule of Niglassar. Yet he did not save "41" or "43" or some other reference, but "40" which suggests that in the conversion, he is assigning 4 years of Niglassar. He does this in other places as well.
Now it's hard to absolutely say this is what he's doing, but you can't rule out the possibility that he's just being very Jewishly clever. That is, if he wanted to leave a record that Evil-Merodach ruled 18 years, knowing this would be suppressed if taken seriously, one way to do it is to appear contradictory, unreliable and just plain ridiculous and no one will bother you, you can publish what you want without being suppressed.
Again, I don't blame anyone for dismissing this as a "reference" but since other indicators are by deductation that he must have ruled 18 years, you can't absolutely say that Josephus' reference to the "forty years" for Niglassar, a ridiculous notion beyond even being simply "wrong" since this contradicts himself elsewhere, wasn't a "decoy" to distract outsiders. If he did make this ridiculous reference in conjunction with the 18 years intentionally, then he's brilliant. If he were taken seriously, then this reference would not have survived. We just have to figure out what is the truth and what is the decoy.
So sure, I can believe he was on drugs, crazy, why not? But did he actually believe that Niglassar ruled for 40 years, second only to Nebuchadnezzar's long reign, contradicting himself? I don't think so. My money is on that he knew exactly what would happen if he claimed Niglassar ruled for 40 years right next to the correct 18-year reference of Evil-Merodach. He knew it wouldn't be taken seriously, but he also knew it would not likely be suppressed. It was a clever way of preserving this critical reference.
JC