The reason why we don't have such a book is simply because nobody has the slightest clue as to how things work at the macro level. We got as far as figuring out

The reason why we don't have such a book is simply because nobody has the slightest clue as to how things work at the macro level. We got as far as figuring out a few dozen cells at a time, but beyond that it's really anyone's guess. We don't even know what the _questions_ should be in this field, let alone the answers. I suspect it's also strongly discouraging to newcomers because things just start looking very obviously intractable very early on, modeling of large numbers of neurons sufficiently well is mathematically near impossible, readout is mostly destructive to the specimen (and in ghastly ways - the specimen has to be alive and awake for it to even be possible), and completely impossible in humans, though Neuralink might provide a much needed boost there. Speaking of Neuralink, I think this un-developedness of the field is why Musk is pursuing it. This is, in many ways, the _real_ last frontier - understanding ourselves. There won't really be much to understand beyond that, since it is but a small step between full understanding and the ability to replicate, and possible eclipse what we have.