Taking a tip from Mastodon, I've been reading about how to "gut" a book — a grad school hack for streamlining the process of extracting key information from academic texts. There's no fixed method, as far as I can tell, but you can get a sense the basics by comparing the variations detailed at Northwest History, or writer Anne Helen Peterson's blog, or Savage Minds
The name of that last citation feel apropos: the process they're all describing is somewhat savage. Some author has taken the time to develop their position, marshal the available evidence, structure it all into an argument, and write the whole thing out, sometimes even with a modicum of style. And what do you do? You read the introduction and conclusion, take notes on the index, and scavenge the rest for parts. Writers like Peterson may downplay the unsavoriness of the process, but I doubt any of the authors of the aforementioned blogs like to think of their own books being gutted.
It is interesting, though, the way the practice conditions the standards we might apply to a work. "Needless to say, this is a strategy that works only for good books," writes Christopher Kelty in that Savage Minds post, adding that the technique "will only confirm the badness of a bad book." And what are the qualities that make a book good or bad? Kelty is less specific. All we can say for sure is that they're the same qualities that make a book guttable. How convenient!
It seems reasonable to suppose that there's an historical process at work here — that the practice of gutting has been made possible by the codification of certain conventions insisted upon mainly by publishers. Galileo's Dialogues Concerning Two New Sciences doesn't lend itself particularly well to gutting, but I doubt very many people would call it a bad book on that account. (Nor would I say it qualifies for the philosophy exception, except in the broad sense that all science was classed as "natural philosophy" until the modern era.) What's changed is not the quality of argument, but frequency with which it's adapted to a form that lends itself to gutting. And for that we likely have the rise of the academic press to thank.
All this may make a book useful, but a useful book is not necessarily a good one. A book may lend itself to the scalpel and still be wrong. If its wrongness arises from the details, rather than the mainlines of its argument, then gutting may fail to reveal the weak points. Conversely, a guttable book may also be a good book, but its goodness need not be a function of its digestibility.
That said, given that so many modern books yield so readily to the process, why not gut them? After all, life is brief, and the research never ends. At some point, you simply call it quits, but in the meantime, triage is a must. We ought, though, to apply almost the inverse standard: gut the mediocre texts, the time sinks that contain some useful information or a worthwhile argument, but which are otherwise unrewarding. The genuinely good books should be read in depth and savored.