Herod finds out that they speak of a prophecy which neither himself, his scribes, or anyone else in Jerusalem appear to have the first clue about. Apparently, it speaks of the Messiah being born in nearby Bethlehem. Who knew?! Of course, had this been general knowledge, all of the world would have known Bethlehem was the place to be, they would have had the entire country there for the census (as in 41 generations, everyone could claim to be of the house of David) and so on.
Matthew doesn't tell us that "neither himself [Herod], his scribes, or anyone else in Jerusalem appear to have the first clue about" the Bethlehem prophecy. Rather, when Herod asks where the Messiah is to be born, the religious leaders tell him. At a minimum, they knew of the prophecy. Whether the Jerusalemites other than Herod and the religious leaders knew of the prophecy is an issue Matthew doesn't address. Even Herod's knowledge of the matter is unclear.
People often ask questions for reasons other than ignorance. Questions are often asked to make a point or get confirmation from others, for example (e.g., Matthew 22:20). Herod's question in Matthew 2:4 could have resulted from ignorance, but may not have. He would have had reason to ask the question even if he was confident about the answer, suspected the answer and wanted confirmation, or considered Bethlehem a possibility, but wanted more information. Getting confirmation that the magi went to the wrong place, Jerusalem rather than Bethlehem, would provide evidence for Herod and others involved that the magi were wrong about the birth of a rival king. If the star and whatever other sources the magi were relying on led them to the wrong location, or allowed them to go to the wrong location, the credibility of their claim would be undermined. It turned out that the magi weren't dissuaded much. They just changed their course and headed for Bethlehem. But trying to cast doubt on their claim by citing a reason to expect the Messiah to be in another city instead would make sense. Matthew doesn't tell us whether that was Herod's intent, but it's one possibility among others. His question makes sense even if he already had significant knowledge about where the Messiah should be born.
There are a lot of possible scenarios behind Herod's question, and Matthew doesn't give us much to go by. That isn't what he's focused on. Since Pearce is trying to answer some questions Matthew didn't answer, Pearce had better be able to substantiate the answers he provides in his objections. He hasn't done that. Rather, he assumes answers consistent with his objections while ignoring alternatives.
As for the census, it wasn't ancestral. And people's decisions about where to live would involve far more factors than where the Messiah was expected to be born. Why should we think that most people would move to Bethlehem just because the Messiah was expected to come from that city at an unknown time? A lot of people expect a messiah, prophet, or other leader of some sort to come from or return to a particular location without moving to that location to live there. And where does Pearce's reference to "all the world" come from? I doubt that many people from Europe or South America, for example, had much knowledge or concern about a Messianic reading of Micah 5. It doesn't follow that the Messianic interpretation wasn't popular among ancient Jews.
This long term approach leading to the killing of a number of children under two is thus nonsensical, and it is not referenced at all in any other place, any other Gospel, any history of Herod (he is a well attested ruler).
The fact that Herod is a "well attested ruler" doesn't tell us whether we should expect the Slaughter of the Innocents in particular to be mentioned in specific sources. I've addressed issues like these elsewhere.
However, Herod’s affront at the time would lead him, surely, to accompany the Magi by force.
If Herod thought he could successfully manipulate the magi, as he had so far, why would he complicate matters by accompanying the magi by force? Herod could covertly execute the child after getting further information from the magi, who had already been so cooperative with him. Why take the less efficient route of accompanying the magi by force in order to carry out an execution that wouldn't be covert? And why think the magi would go along with it? If they were devoted to the child enough to travel so far and to take the other steps they'd taken, there would be a good chance that they'd rather die than knowingly lead an executioner to the child.
Something that complicates Pearce's objection even further is our ignorance of how Herod viewed the magi's claim. We know that he opposed the claim they were making, but we don't know much about the reasoning behind his opposition. Given Herod's apparent mental instability and moral corruption, it's possible that he thought the Messiah had been born and wanted to execute him. But that would involve quite a high degree of mental illness and/or evil. It seems more likely that he didn't think the Messiah had actually been born. But what would he have made of the magi's claim, then? There would be multiple options within the framework of ancient Judaism.
The magi might have been delusional. They might have been deceived by other people. They might have been deceived by demonic activity, sorcery, or the like. Or they may have been deceivers themselves. There's also the possibility that Herod was unsure of what to make of the magi's claim or wavered on the matter. Did he think there might be other individuals working with the magi in some manner, such as other magi who would still be involved even if he dissuaded or executed the magi who had come to him? There are multiple scenarios in which Herod's behavior described in Matthew 2 would be realistic. We don't have enough information to determine which scenario actually happened, but we don't have to know which scenario occurred in order for Pearce's objection to fail.
From Herod's perspective, the heart of the problem was the child, not the magi. Giving the magi a longer leash rather than a shorter one would be a better way to find the child and get at the heart of the problem. If Herod thought the magi were delusional, deceptive, or demonically deceived, for example, he would want that delusion, deception, or demonic activity to identify the child, so that the child could be removed as a threat. Doing something like executing the magi or threatening them wouldn't be the best approach to take in order to accomplish Herod's ends.
Pearce goes on:
Moreover, the Star reappeared, so it would have been trivially easy to go there independently of the Magi. In fact, unless God only magically made the star visible to the Magi, the whole of Jerusalem could have gone to see the newborn Messiah; the entity they had surely been waiting to see for quite some time.
I've addressed the nature of the star here. The star seems to have been a local phenomenon intended to guide the magi, not other groups, such as the people of Jerusalem. Since the star apparently disappeared prior to the magi's arrival in Jerusalem and didn't reappear until after they left the city, the Jerusalemites wouldn't have had anything to follow when the magi left. And for reasons I explained in my last response to Pearce, the people of Jerusalem probably didn't think the Messiah had actually been born and probably didn't know the magi were going to Bethlehem to look for the Messiah.
Herod’s anger at the Magi’s failed return shows that he was not anticipating this
I gave multiple reasons why Herod might ask about the timing of the star prior to the magi's failure to return to him. Pearce's comment above doesn't interact with any of the reasons I cited.
And people often get angry even when they expected what they're angry about or considered it a high possibility. An employer who thinks there's a good chance that one of his employees will dishonestly call off sick the day after Christmas is probably going to exhibit some anger when the calling off occurs, even though he knew ahead of time that there was a good chance that it would happen.
Engwer makes his points on a point by point basis and claims how things might be able to happen as reported, without taking all of them as a whole and seeing the compound probability.
A "compound probability" would depend on the value of each probability involved. I deny that we have the sort of string of improbabilities that Pearce claims we have.
I did not say Herod acted irrationally anywhere.
My point was that Herod acted irrationally in some contexts that Pearce accepts as historical, regardless of whether Pearce has acknowledged that those contexts involved irrationality. It was in Pearce's interest to avoid explicitly acknowledging the irrational nature of Herod's behavior on those other occasions. But the irrationality is there.
For example, Pearce refers to how Herod had one of his wives executed on dubious grounds, then regretted the execution shortly after. Was that behavior rational in the sense of being the best course of action Herod could take under those circumstances? No, it's a highly problematic course of action that falls well short of being the best option. Similarly, Herod tried to get people to mourn at the time of his death by having other significant figures executed around the same time. Is that the best way to try to get people to mourn around the time of your death? Is there even much value in having people mourn the death of others when you die? Wouldn't there be a good chance that people would refrain from mourning your death even more, since you did something so evil just before you died (i.e., unjustly arranging the death of those other individuals) and since those who would have mourned for you would have their mourning diverted to the loss of so many other people as well? Herod's behavior on such occasions doesn't rank high on the rationality scale. Yet, such actions by Herod are commonly accepted as historical, including by Pearce.
On pages 129-30 of his book, Pearce quotes what Josephus wrote about Herod's behavior during the first instance cited above, when he had one of his wives executed. Josephus refers to how Herod was "stark mad and leaping out of his bed he ran around the palace in a wild manner". Pearce's own quote of Josephus goes on to refer to how Herod's jealousy and rage were "ungovernable" and how Herod changed his mind about executing his wife "as soon as his passion was over". Then Josephus refers to how Herod "could not think she was dead but he would appear under his disorders to speak to her as if she were still alive". Doesn't sound very rational to me.