Andy:
Great topic. Some of the good old architect/writers had some interesting and specific things to say on this subject, Hunter and Thomas particularly. I'll find them and reprint them when I have more time.
I get the feeling, though, that neither of them (or any of the good "Golden Age" designers and so forth) meant that trying to be "natural" HAD to mean that an architect must make a course that looked as if he hadn't touched it at all. Their reasoning, in what they said, was that that almost had to be impossible due to the basic requirements of golf itself and its elements like greens and bunkering (and maybe fairways). They simply stated that those things, particularly, just aren't offered by nature (on almost all sites). So those things, at least, must be made by them but to blend them harmoniously with what they'd found on the site that is its "nature" is the real deal!
That, I think is where the best architects are clever and good. NGLA is probably the best example. It is clearly touched by its designers and obviously dramatically so because they needed to do some things (or felt that they did) that worked really well for golf and how the ball played on all of it. But as dramatic and radical (engineered) as they got, somehow they harmoniously blended their "architecture" to the "nature" of the site. Even the best of architects today seem a bit unsure exactly how they did it and even Bill Coore (who probably can pick up exactly how they did it) says he still can't believe HOW they dreamed up or saw the possibilities that they came to "create".
Being natural is great but at the end of the day the golf course has to play fun and exciting in numerous and sometimes very diverse ways and if an architect can't find those things on the site then he has to make them and/or enhance them somehow and hopefully make them look like a really good "blend" into the site's "nature".
That being said, I admire the most the architects who take the time to really study a site to find "all the golf that is there before they got there" and then if they need to create more or enhance it somehow they do that harmoniously. Most modern architects don't seem to take the time to do that and they may not because it may not even occur to them and that of course is where things start to look "unnatural" and they fail to "blend" at all.
All of this is very fascinating and one could even take the subject all the way back to some of the basic instincts of Americans. The original settlers of this continent were sometimes of two very diverse minds about the "nature" of where they came to live. The "west pushing" settlers of this continent tended to feel that they had to "conquer" nature just to survive in it!! But eventually along the way in doing that, I think, they also came to notice its extraordinary beauty and majesty and to respect it in a bit of a schizophrenic sense.
Some of these early settlers came to view themselves as "nation builders" and as such the idea of how they came to view nature (or anything else that stood in their way) even got a name--called "Manifest Destiny"!!
"Manifest Destiny" sort of became imbued in the national pyshe of America (and in many Americans) and has resulted in our national ethos (and reputation) as "can do" people.
Clearly that ethos has it good and bad sides in many many ways but a part of it is still their view of "nature", I'm sure. There are still many vestiges and ramifications in all of this, I'm sure, and one might be how modern golf architects view how they do what they do!
As a bit of a humorous example one might say that an architect like Tom Fazio is a true "Manifest Destiny" American, since he seems challenged and even proud of his ability to "conquer" and make better what he finds with sites that he seems to believe constrain him and his creative instincts. While those like Coore, maybe Doak and some of the others might be viewed a bit more like American Indians who seemed more willing to do things in concert with "nature" rather than change and "conquer" it. American Indians seemed content to migtrate about the land without changing it or even bothering to "permanently settle" as did the "Nation Builders" (and dedicatedly so)!
These attitudes can even be reflected in the comments and thoughts of some of our present architects. Fazio seems to say, and proudly so; "Look what I did and brilliantly so." While a guy like Ben Crenshaw has said the basic idea is to; "Get out of town like you never did much at all."
Very interesting stuff and good topic on your part!