Here is an excellent post by Michael Kruger at Canon Folder:
By Michael Kruger
“You can’t say everything.” This is one of the refrains I often cite to my students as we discuss historical documents. When ancient authors put quill to papyrus (or parchment), we need to remember that they had a limited amount of space, a limited amount of time, a limited number of goals, and often a very specific purpose for which they wrote.
Inevitably, therefore, an historical account will include some things that other historical accounts (of the same event) might omit, and they might omit some things that other historical accounts might include.
This reality is particularly important to remember when the Gospel accounts are analyzed and compared with one another. Differences aren’t (necessarily) the same as contradictions. Each author inevitability gives a limited perspective on the whole. They can’t say everything.
Unfortunately, in Bart Ehrman’s recent book, How Jesus Became God–The Exaltation of a Jewish Preacher from Galilee (HarperOne, 2014), this particular principle goes unheeded. In order to demonstrate contradictory Christologies in the New Testament (particularly amongst the Gospels) Ehrman leans heavily on what the Gospel authors don’t say. Put directly, Ehrman uses an argumentum ex silentio (argument from silence).
This discussion of Ehrman’s use of the argument from silence will be the final installment of a series of posts interacting with and responding to his new book (for the prior post see here, here, and here).
For Ehrman, a central example of contradictory Christologies comes from comparing Mark with Matthew and Luke. Mark, he argues, believes Jesus became divine only at his baptism, and was a mere man prior to that point. Matthew and Luke, in contrast, present Jesus as divine even from birth (since he was born to a virgin).
But, how does Ehrman know that Mark rejects the virgin birth, and therefore rejects the higher Christology that goes with it? Simple: Mark doesn’t mention it. Ehrman states,
[Jesus] was already adopted to be God’s Son at the very outset of his ministry, when John the Baptist baptized him. This appears to be the view of the Gospel of Mark, in which there is no word of Jesus’s pre-existence or of his birth to a virgin. Surely if this author believed in either view, he would have mentioned it (238).
Here is where we see the clear use of the argument from silence. Ehrman assumes that if a New Testament author doesn’t mention something then they must not believe it. But, there is a reason why arguments from silence are regarded as fallacious. As noted above, we simply do not know why an author included some things and not others; and it is very dangerous to suppose that we do.
Think, for example, of Paul’s discussion of Jesus instituting the Lord’s Supper in 1 Cor 11:23-26—a topic he never discusses anywhere else. Now imagine for a moment that (for some reason) we didn’t have 1 Corinthians. We might conclude that Paul didn’t know about Jesus instituting the Lord’s Supper; indeed we might even conclude that Paul didn’t believe in the institution of the Lord’s Supper. And we would be flat out wrong.
Likewise, to suppose that Mark’s omission of the virgin birth means he doesn’t believe in the virgin birth (and thus must not share Matthew and Luke’s Christology) is an unsustainable line of reasoning. After all, Mark doesn’t even include a birth account! Should we conclude from that fact that he didn’t believe Jesus was born at all? Indeed, Mark omits many other stories that the other Gospels include; shall we conclude that he did not know any of them? Historical records are inevitably limited in scope; an author cannot say everything. Thus, we cannot draw hard and fast conclusions about things an author did not include.