What effect does the opening paragraph have on readers? What is learned about the narrator?

The first paragraph of the story has a lot of information in it, but most of the information has to do with things we infer about the narrator from the way he writes, rather than what he actually says.

There are a few outright facts in the paragraph: we learn that the writer is old. We learn that he has know many law copyists or scriveners. We learn that Bartleby was the oddest one he ever knew.

When we consider how the paragraph is written, however, we can infer quite a bit more. The paragraph is written in a overly formal, legalistic way. The writer is always qualifying his assertions: he means to say that scriveners are fascinating people, but he says only that they "would seem" interesting -- they appear to be interesting, but they might not be interesting at all. Nothing has been written about them -- at least nothing he knows of. He could tell stories that "might" make "good-natured gentlemen" smile. His care in expression, we assume, indicates that he is accustomed to writing like a lawyer.

There are certain assertions, however, that he does not qualify. Bartleby "was the strangest" scrivener he had ever known. No biography of him can be written, because there "no materials exist" on which to base such a work. Even more, he flatly asserts that this "is an irreparable loss to literature." This almost passionate declaration really stands out. There is a hint here that the lawyer really cares for Bartleby, which we find out is indeed the case as we read on.

Of course, the other thing the reader takes away from this paragraph is a certain amount of curiosity about Bartleby, this person about whom so little is known, beyond what the lawyer's "own astonished eyes saw" of him. This lack of information is intriguing. What was so astonishing? Why is the lawyer writing this, if he knows so little about Bartleby?

Finally, we get a sense that maybe, through this writing, legalistic as it may be, the lawyer feels he might somehow be able to connect with Bartleby, or, at least, understand own his own feelings about him. I think that the end result of this paragraph is to show the lawyer as a person who, despite his penchant for legalistic qualification, is still at bottom a feeling individual. And for us readers -- we want to read more.