What does it mean by "take something into the bargain" and the following sentence in this context?

Question

The story of Rip Van Winkle may seem incredible to many, but nevertheless I give it my full belief, for I know the vicinity of our old Dutch settlements to have been very subject to marvellous events and appearances. Indeed, I have heard many stranger stories than this, in the villages along the Hudson; all of which were too well authenticated to admit of a doubt. I have even talked with Rip Van Winkle myself, who, when I last saw him, was a very venerable old man, and so perfectly rational and consistent on every other point, that I think no conscientious person could refuse to take this into the bargain; nay, I have seen a certificate on the subject taken before a country justice and signed with cross, in the justice’s own handwriting. The story, therefore, is beyond the possibility of doubt.

This is from the short story, Rip Van Winkle by Washington Irving. Here, the narrator is trying to say what he previously told is absolutely true, there's no room for doubt. (though it's actually not. it's fiction.)

Now I get the overall point of the paragraph, but don't understand what the bolded parts mean exactly, especially the meaning of "take this into the bargain" and the whole of the following sentence.

I've looked up the meaning of "into the bargain" and still not sure if the definition fits here or if it has other meaning. As for the next sentence, I have no idea even about the structure. Is it "I have seen a certificate [on the subject (taken before a country justice and signed with cross)]"? What does "taken before a country justice" mean(I know the individual meaning of these words but can't make any sense all put together.)? Also, what's "cross" and "justice's own handwriting"?

Thanks in advance.

Answer 1

He's saying that you should take the evidence the author is mentioning into consideration.

Basically, he's attesting a story that seems unbelievable, but he's saying that he's got a significant amount of evidence to back up that the story actually happened, and that Mr. Rip van Winkle was a very reliable source. As a result, a reader should consider these facts before dismissing the story as a fabrication.

What does "taken before a country justice" mean(I know the individual meaning of these words but can't make any sense all put together.)? Also, what's "cross" and "justice's own handwriting"?

It means that he's taken a document attesting that this information is true before a court and gotten the judge to personally sign off on its accuracy. That's what the "cross" it mentions is - the judge's signature, since back in the days before everyone could read, people sometimes signed documents by simply marking an "x" rather than signing their name.

Since the story itself is fictional, none of this is true, but it's written from the perspective of someone in-universe to whom it is true, and who has gathered the evidence he mentions.