Regarding Hakuin's Precious Mirror Cave

I still haven't gotten entirely through the book, but I will say that at the very least:

• It's useful to read books like this because you can see how very much of what's taught today goes "way back."  Hakuin's influence on Zen cannot be over-emphasized, unless, I guess, you're one of those "Soto-only" folks, in which case, you don't know what you're missing.
• It's also useful to read this because even though some material seems like a repetition of earlier works (much of Chapter 1 is covered in Wild Ivy), the repetition is useful in itself.

I'll have more to say later.