I, too took the Silva homestudy course from Nightingale and was impressed by its simplicity. I am using the first steps for "programming myself" daily.

What bothers me, though is the basic concept that stands behind it all. Citing Silva, Bob Stone (one of the lecturers in that tape series) says somewhere on the tapes something like: "All you see around you has it's origin in spirit." this then leads to the concept, that if you bring things/ situations whatever back into your spirit, namely your mind you can mold things your way. At least this is my understanding of it.
Now, being educated in a very materialistic way this is very hard to swallow. I might go as far and agree that human made things are originated by spirit in the sense that humans thought about it before making it, (but isn't the brain and how it works in the end also a very materialistic matter?).

But I see no way that nature in all it forms and variations - living or non-living - could be the result of a spirit's blueprint.

Happy Day