Personal Knowledge, by Michael Polanyi.
http://www.amazon.com/Personal-Know...=sr_1_2?ie=UTF8&s=books&qid=1256325405&sr=8-2
Profound understanding of the theory and nature of knowledge. Sets forth the thesis that all our knowledge, from the most basic to the most sophisticated, whether that of science, art or religion, has as an inescapable component an intuitive, personal participation of the knower.
For us as users of tools with the intention of making works of art, one of his most pregnant observations is that, "We dwell within our systems of articulate meaning as we dwell within our bodies." Learning to ride a bike offers an example of this. The process involves focusing on learning the details until we can put them all together, forget about them as things in themselves and just RIDE (even though we can't explain it all in words.) Learning to play a cello involves a similar process and so does using a camera. (And GAS probably doesn't help either one....)
We know all this, roughly, and mostly, but it's a fascinating book which offered me, at least, more than a nudge in the right direction.
Cheers,
Irenaeus