What is 'chiasm'?
Chiasm is a literary technique by which the contents of a portion of text are structured in such a way that they could be laid out in a ">" shape...
A) This is an example of a chiasm
B) which has been reformatted to illustrate the concept
C) that each element in a chiasm corresponds to another element
D) except, perhaps the central element, which is often being emphasized.
C') Otherwise each element corresponds to another element in the chiasm
B') and if you were to reformat the whole thing in a '>' shape it would be clear
A') that it is in fact a chiasm.
...so A corresponds to A', B to B', C to C', etc. Sometimes there is a central element, in which case, the chiasm often points the reader to that central element, where the emphasis of the entire chiasm lies.
A more Biblical example
I found this by doing a quick Google search for "chiasm Bible". The author of the site claims that Genesis 3:5 – 3:22 is a chiasm.
A) You will be like God, knowing good and evil (5)
B) They made coverings of fig leaves (7)
C) Wife as yet unnamed (8)
D) Adam questioned (9)
E) Eve accused and questioned (12-13a)
F) Serpent accused (13b)
F') Serpent’s curse (14)
E') Eve’s curse (16)
D') Adam’s curse (17-19)
C') Wife is named Eve (20)
B') The LORD God made them tunics of skin and clothed them. (21)
A') Man is like one of Us, to know good and evil. (22)
Pretty cool, eh?
My concern
Here is my concern. I'm looking at the "chiasm" I just included, and I'm wondering... what happened to verses 6, 10-11, and 15? Maybe they were insignificant to the chiasm so they weren't included... So then, how do we decide which verses to include in our chiasm and which to leave out? Do we just tinker with the text until we are able to "make something work"? Then I'm wondering, why doesn't it start at verse 4, or verse 1? Do we just pick a convenient verse that allows us to call it a chiasm? Aside from verse selections, the text has to be summarized in just the right way to make it look chiastic. This whole procedure can quickly begin to sound more like eisegesis than exegesis.
To make matters worse, it is relatively easy to "see" a chiasm where none exists. To prove my point, I went to Bible Gateway and typed in some random book+chapter+verses and fit them into chiastic structures. There are three examples provided below. These are not actual chiasms! I made them up to show how easy it is to succumb to "chiasmania." Again, take note that these chiasms are artificial and are not to be trusted!
Formerly dead (5a)
God made us alive in Christ (5b-7)
By grace (8a)
Through faith, which is a gift (8b)
Not by works (9)
God made us alive in Christ (10)
Formerly dead (11-12)
James confronts those guilty of showing partiality (6-7)
The royal law (8)
You are a transgressor! (9)
Whoever stumbles in one point becomes guilty of the whole law (10)
You are a transgressor! (11)
The law of liberty (12)
James confronts those guilty of showing partiality (13-14),
an opportune time for the devil (13)
Jesus' mission field (14)
Jesus the teacher (15)
Jesus prepares to read (16)
Isaiah was handed to Him (17a)
Jesus prepares to read (17b)
Jesus the preacher (18a)
Jesus' mission field (18b)
the favorable year of the Lord (19)
Again, I literally made these by just randomly picking some book+chapter+verses off the top of my head, typing them in at Bible Gateway to see what they said, and then forcing them into a chiastic structure. There is no reason to think any of these were actually intended to be chiasms.
My question
When we think we are seeing a chiasm in the Biblical text, how can we be sure that we are actually seeing something that was intended by the author, and not just imposing our own chiasmaniacle agenda on the text? Is there an exegetical procedure for identifying a chiasm that can help us to ensure that we are being faithful to authorial intent?