A lot has been said in recent articles here about the hallucination theory as it relates to the evidence we have from the writings of Paul. In this post, I want to focus more on non-Pauline sources.
In recent articles responding to material posted here, Matthew Green and Dawson Bethrick have raised objections to the resurrection accounts we have in the gospels and Acts. Green has suggested that Luke's gospel, for example, contains unhistorical details written in response to Docetism. Bethrick has gone even further, quoting Earl Doherty and suggesting that the Jesus of the gospels might be radically different from the Jesus Paul believed in.
Why is dismissing the data in non-Pauline sources so important for proponents of the hallucination theory? Because while some of the data from Paul is inconsistent with a hallucination theory, the data in non-Pauline sources is even more so. The non-Pauline accounts describe an empty tomb, the touching of Jesus' resurrection body, etc.
To get an idea of how significant a problem this non-Pauline data is for advocates of the hallucination theory, think about the number of people involved. The gospels and Acts were composed by four different authors, and one of those authors claims to have relied on multiple sources (Luke 1:1-3). When documents like Hebrews and 1 Peter appeal to apostolic authority, we're seeing, in part, an appeal to eyewitnesses of the resurrected Christ. We know that eyewitnessing the resurrected Jesus was necessary for apostleship (Acts 1:22, 1 Corinthians 9:1). Documents like Hebrews and 1 Peter reflect a widespread early concern for apostolic authority and, thus, eyewitnesses to the resurrection. And the evidence we have regarding what the early Jewish opponents of Christianity were arguing about the resurrection (Matthew 28:15, etc.) would be representative of many people in Judaism, not just one person. A lot of people were involved in producing the historical data we have related to Jesus' resurrection. Any theory that proposes some sort of deception or change in belief will have to account for widespread deception or widespread change of belief.
Paul wasn't the only early source concerned about the details of the resurrection. It's unlikely that we would see such a widespread acceptance of a physical view of the resurrection and the evidence for it in these non-Pauline sources if Paul and his contemporaries believed in a non-physical resurrection or believed in a physical resurrection without much concern for evidence supporting it. Those who suggest some sort of radical change from the time of Paul to the time of the writing of the rest of the New Testament are suggesting something highly unlikely.
We know, from 1 Corinthians 15 and other evidence, that the earliest Christians were concerned about eyewitness testimony and preserving information about Jesus' resurrection appearances. It would make sense in such a context for accounts like the ones we see in the gospels and Acts to be preserved. But since those accounts present so many problems for the hallucination theory, proponents of that theory will often suggest that these resurrection accounts were either entirely fabricated or altered around the time when the documents in question were composed. Thus, Luke or his sources, for example, either made up the resurrection accounts in Luke and Acts or took historical accounts and added unhistorical elements to them. What we're to conclude, then, is that the early Christians either didn't preserve any of the eyewitness accounts in documents like the gospels and Acts or preserved them in an altered form.
Given the value the early Christians placed on eyewitness testimony, and specifically on eyewitness testimony to the resurrection, it's unlikely that they would fail to preserve any detailed resurrection accounts. And given the fact that eyewitnesses and contemporaries of Jesus and the apostles were still alive when documents like the gospels and Acts were composed, theories like what's described in the paragraph above are unlikely to be true. The more radical an alteration of the historical accounts, the less likely those alterations are to gain widespread acceptance. Even on matters less significant than a resurrection, disciples of a teacher would tend to be more careful in preserving tradition than critics often suggest:
"The burden of proof thus rests with New Testament scholars who betray an unduly skeptical bias toward the Gospel accounts (on the question of the burden of proof, cf. Goetz and Blomberg 1981: 39-63); such scholars must imply that disciples who considered Jesus Lord were far more careless with his words in the earliest generations of Christianity than first- and second-generation students of most other ancient teachers were (see Davies 1966a: 115-16; Benoit 1973/1974: 1:33). Especially given how much of Jesus’ teaching was disseminated in public during his lifetime, the sort of ‘radical amnesia’ this skepticism requires of Jesus’ first followers (Witherington 1990: 14) is certainly not typical of schools of other early sages." (Craig Keener, A Commentary on the Gospel of Matthew [Grand Rapids, Michigan: William B. Eerdmans Publishing Company, 1999], p. 29)
The issue here isn't whether any mistakes could be made. Rather, the issue is whether it's likely that so many people could be misled into accepting such radically unhistorical accounts as we supposedly have in sources like the gospels and Acts. If two or three details in the resurrection narratives are unhistorical, that's one thing. But if critics want to suggest that every gospel is radically unhistorical in its resurrection accounts, and that Acts is radically unhistorical, and that the early enemies of Christianity who acknowledged the empty tomb were wrong about such a tomb even existing, and that the sort of early post-apostolic resurrection traditions we see in Ignatius of Antioch, for example, are highly inaccurate, then that's a different matter. Saying that people sometimes hallucinate or sometimes forget things doesn't justify a conclusion that widespread hallucinations, memory losses, apathy, etc. occurred every time skeptics need it in order to maintain their naturalistic theories.
In an article posted here last month, I discussed some of the evidence we have for the credibility and traditional authorship attributions of the gospels. We know that the early Christians wanted evidence for the authorship attributions of the books of the New Testament. Disputes occurred over books like Hebrews and 2 Peter, and the early Christians acknowledged the existence of those disputes. Yet, the gospels of Matthew, Mark, and Luke were universally accepted, and John's gospel was almost universally accepted. (A small group opposed it on doctrinal grounds, but they had no significant historical case against Johannine authorship.) We have good reason to accept the traditional authorship attributions of all four gospels. And the early claim that Mark relied on Peter as his primary source is credible, for reasons such as the ones discussed here. Thus, the gospels can be said to represent the testimony of Matthew, Peter, and John, who would have been eyewitnesses of the resurrection events. Luke wasn't an eyewitness of those events, but he was an eyewitness of Paul, and he was in contact with James (Acts 21:18), so his testimony is significant, especially with regard to Paul.
Proponents of the hallucination theory therefore have a motive to look for reasons to dismiss what the early Christians reported about the origins of all four gospels and the book of Acts. If these documents were written by two eyewitnesses and two disciples of other eyewitnesses, then the claim that every one of these documents is radically unhistorical in its resurrection accounts becomes even more unlikely. But even if the early Christians were correct about the identity of just one of these four authors, there would be significant problems for the hallucination theory. Thus, the proponent of such a theory is put in the absurd position of either trying to dismiss every one of the authorship attributions of the gospels and Acts or suggesting that sources so close to the truth were somehow mistaken.
Think about what the gospels and Acts tell us. We know that expectations play a major role in hallucinations. And all four authors tell us that the resurrection witnesses weren't expecting to see Jesus resurrected (Matthew 28:1-6, Mark 9:10, 16:1-3, Luke 24:11, John 20:25, Acts 9:1, etc.). We also know that while there can be general similarities among the hallucinations of different people, higher levels of detail are unlikely to be shared. Hallucinations occur within the mind of the individual. Yet, all four gospel authors report that the resurrection witnesses shared detailed experiences at the same time (Matthew 28:1-7, 28:16-20, Mark 16:5-8, Luke 24:13-31, John 21:20-23, Acts 1:3-11, etc.). Hallucinations don't interact with the physical world, yet all four gospel authors refer to physical evidence produced by the resurrection (Matthew 28:9, Mark 16:4-6, Luke 24:42-43, John 21:9-13, etc.). Similarly, the early Jewish opponents of Christianity acknowledged the empty tomb, and Ignatius of Antioch reports a possible extra-Biblical tradition involving the disciples' touching Jesus resurrected body (Letter To The Smyrnaeans, 3).
Since the popular Jewish view of resurrection involved transformation of the physical body that died, and since the early Christians were claiming a physical resurrection, we would expect people who thought they saw a resurrected person to look for physical evidence. The physical evidence mentioned in the gospels and other early sources therefore makes sense in a Jewish and Christian context, so there's no need to speculate that the early Christians were fabricating physical evidence in response to Docetism. A concern for physical evidence would have existed all along. There wouldn't have been belief in a physical resurrection without it.
The problem for advocates of the hallucination theory isn't just that it's difficult to dismiss the traditional authorship attributions of the gospels and Acts. Even if we were to grant their dismissal of the traditional authorship attributions, why should we think that the gospels and Acts give us accounts radically different from what the eyewitnesses reported?
There are many details within the resurrection narratives that suggest historicity. See here, for example. Critics will often make much of something like the alleged contradictions in the accounts of Paul's conversion in the book of Acts. But if the author was Paul's companion Luke or anybody else who had early and reliable information on Paul, which seems probable, then how likely is it that the accounts of Paul's conversion would be wrong in every detail? Perhaps the element of Paul's conversion that critics most desire to dismiss is the report that Paul's companions shared Paul's experience in some manner. Such a shared experience is problematic for any hallucination theory. Yet, all three accounts in Acts mention the fact that Paul's companions shared in the experience (9:7, 22:9, 26:14). The three accounts can be reconciled, but even if we were to grant the claim that they're contradictory, why should we think that a first century author (apparently somebody who knew Paul) would three times refer to an element of Paul's experience that didn't actually occur? The author of Acts apparently was with Paul when he spoke about his conversion (Acts 26:12-27:2). The same author also reports that Paul's conversion was coordinated with a supernatural experience Ananias had, and the author claims to have seen Paul perform miracles. Did Ananias and Paul just happen to have independent hallucinations that brought them together? Was Luke (or some other author of Acts) mistaken about every one of the miracles he thought he saw?
The typical answer in some circles is to say that every one of these early Christian sources might have been mistaken, so it's reasonable to conclude that they were mistaken. That sort of failure to distinguish between the possible and the probable is a hallmark of modern skepticism.
Any hallucination theory that's proposed needs to account for non-Pauline data like what I've discussed in this article, and making a vague dismissal of the gospels and Acts isn't sufficient. Paul died in the 60s. Eyewitnesses and contemporaries of Jesus and the apostles lived as late as the second century. To say that a document like Mark or Luke postdates Paul is not equivalent to proving that it was written at a time when people could make up whatever they wanted to make up and gain widespread acceptance for their fabrications. The human faculty of memory didn't die with Paul.
It also won't do to just assume naturalism from the outset:
"The problem here can best be understood, I think, as a disagreement over what sort of explanations constitute live options for a best explanation of the facts. According to the pattern of inductive reasoning known as inference to the best explanation, in explaining a body of data, we first assemble a pool of live options and then pick from the pool, on the basis of certain criteria, that explanation which, if true, would best explain the data. The problem at hand is that scientific naturalists will not permit supernatural explanations even to be in the pool of live options. By contrast, I am open to scientific naturalistic explanations in the sense that I include naturalistic explanations in the pool of live options, for I assess such a explanations using the standard criteria for being a best explanation rather than dismiss such hypotheses out of hand. But [atheistic scholar Gerd] Lüdemann is so sure that supernatural explanations are wrong that he thinks himself justified in no longer being open to them: they cannot even be permitted into the pool of live options. But, of course, if only naturalistic explanations are permitted into the pool of live options, then the claim or proof that the Hallucination Hypothesis is the best explanation is hollow. For I could happily admit that of all the naturalistic explanations on tap, the best naturalistic explanation is the Hallucination Hypothesis. But, of course, the question is not whether the Hallucination Hypothesis is the best naturalistic explanation, but whether it is true. After all, we are interested in veracity, not orthodoxy (whether naturalistic or supernaturalistic). So in order to be sure that he is not excluding the true theory from even being considered, Lüdemann had better have pretty good reasons for limiting the pool of live options to naturalistic explanations. So what justification does Dr. Lüdemann give for this crucial presupposition of the inadmissibility of miracles? All he offers is a couple of one–sentence allusions to Hume and Kant….Now Lüdemann's procedure here of merely dropping names of famous philosophers is sadly all too typical of theologians….Hume’s argument against miracles was already refuted in the 18th century by Paley, Less, and Campbell, and most contemporary philosophers also reject it as fallacious, including such prominent philosophers of science as Richard Swinburne and John Earman and analytic philosophers such as George Mavrodes and William Alston. Even the atheist philosopher Antony Flew, himself a Hume scholar, admits that Hume’s argument is defective as it stands. As for philosophical realism, this is in fact the dominant view among philosophers today, at least in the analytic tradition. So if Lüdemann wants to reject the historicity of miracles on the basis of Hume and Kant, then he’s got a lot of explaining to do. Otherwise, his rejection of the resurrection hypothesis is based on a groundless presupposition. Reject that presupposition, and it’s pretty hard to deny that the resurrection of Jesus is the best explanation of the facts." (William Craig)