Walton's last chapter simply summarizes what he's argued throughout the book, so I won't rehash that here. Instead, I thought I would just give a couple, brief afterthoughts.
I began reading this book with the assumption that this was the academic foundation Walton was providing for his lay work, The Lost World of Genesis 1. As I was reading through the book, I began to wonder if my assumptions were incorrect, and that this was really meant to be a separate work, arguing for less than what he proposes in The Lost World. He certainly does propose less in this work, and so he likely cannot be held to proving too little if the work is taken in isolation to the other. However, his final comments in this book, e.g., that this study has implications for the modern origins debate, seems to confirm what I originally presupposed. In this case, I think Walton did not prove as much as he needed to prove, since ignoring material origins in a creation account that emphasizes functions does not mean that material origins are not assumed as simultaneous with, or even subsequent to, assigned functions.
Overall, I highly recommend this book. It has a wealth of good material for understanding the ancient Near Eastern cognitive environment. It is just a great book all around. Even with my disagreements, I would, and will, give it 5 stars. It's that important of a book. It will be a book that every Genesis scholar will now have to consider in their future commentaries and monographs. So I can only thank Dr. Walton for his hard work in putting it together for us. You can purchase it from Eisenbrauns here: https://www.eisenbrauns.com/ECOM/_3BT1BQABT.HTM
P.S. As just a point of clarification to Dr. Walton. He states in the introduction that he had his epiphany about forms and functions in the Fall of 1998, but I remember him saying this in the Spring of 1997 in our Hebrew Exegesis course, so maybe this was the epiphany before the Epiphany, or maybe it was just a long time ago (can't fault him for exact dates, as I only remember this because my transcripts provide for me the time line for when I was in his class--I don't even remember clearly if he said this in Fall of 1996 when I was taking the course for credit, or in Spring of 1997 when I was just occasionally auditing). In any case, it was nice to have been there when the apple dropped from the tree.