The first half of this book is fascinating, talking about the ability to propositionize within pre-lingually deaf people. There is a good chunk in the middle, though, that feels like Oliver Sacks is making the same point over and over for like five chapters. If I didn't agree ASL was a language going into the book, maybe it would have changed something, but as it is I found it repetitive and vaguely condescending. The end, though. I really enjoyed that.