"Thou coward knight, why wilt thou not do battle with me?" -The Age of Chivalry, Chapter 16
In this sentence, why is do not dost? Very commonly do I see the word dost be used in older text in place of do when using the 2nd person, but rarely do I see it as do. I can't find a grammatical explanation for this - or is it a choice of inconsistency by the author?- or perhaps a choice of fluidity over grammatical correctness?