I liked the C.S. Lewis quote. It seems that we can't not project. We use it to theorize and speculate -- to decide what questions to ask or what to look for. It reminds me of what Dan Jones said, which is that all perception requires some projection. It is part of the way we organize what we experience. He defined projection as "the natural tendency to complete a figure, by a perceiver whose nature is to make meaning of his/her enivronment/or encounter with the world." He listed a number of cues to recognize projection:
*Interpretation -- a hypotheis or a "given" about how things work.
*Moralizing can be a projection.
*Assumptions -- stereptypes.
*Self Righteousness indicates projection of shadow material.
*Strong emotional reaction to others.