The structure of Proverbs 17:21-25

In terms of form, Proverbs 17:21-25 create a chiasm:

17:21- synthetic parallelism
17:22- antithetic parallelism
17:23- no parallelism
17:24- antithetic parallelism
17:25- synthetic parallelism

Given that 17:21 and 25 are thematically identical, the formal chiasm leads us to discover a thematic chiasm as well:

17:21- a father's grief over a foolish son
17:22- the effects of wisdom & folly
17:23- folly reaches its highest degree in wickedness
17:24- the choice between wisdom & folly
17:25- parents' grief over a foolish son

As the chiasm's frame, 17:21 and 25 put a strong emphasis on folly's effect on the family. However, because 17:23, the chiasm's center point, explores how wicked folly can corrupt government institution, the text's subject is the broader society, rather than the narrower family.