A cow produces milk--that is certain--and the milk doesn't come from nothing. Just as a cow must eat grass in order to produce milk, I have to read large ammounts of genuine scientific literature of all kinds--i.e. literature not invented by me--and the final product, my writing, is as unlike the intellectual food as milk is unlike grass (p. 25).
I think that is the way it should be. Notes are fodder. If the final product of one's research retains the character of the notes upon which it is based, something has gone wrong.
So much is sure. The question that remains to be answered is how the material gets transformed into something new and original.