"This chapter addresses a popular argument that is used against those who hold to an inerrant Bible. Essentially, the argument is posed as a question: How can you claim to have an inerrant original text when we don't even have the original text? On its face, this argument has seemed so compelling that some people never get beyond it. This chapter will show what are the underlying assumptions behind this question and why they are fallacious."
Wallace spends many words (indeed this chapter is the longest in the book so far) on whether acknowledged discrepancies are significant, and claims that in terms of doctrine they are not. But he's basing his judgement of what conforms to doctrine on the text that he's trying to validate. This is begging the question. If the doctrine happens to be stated in the missing or disputed text, he cannot know whether the text conforms to doctrine or not, because the doctrine itself is therefore in doubt.
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