In this view, any science begins in the nothingness of ignorance, constructing theories as facts accumulate. In such a world, debunking would be primarily negative, for it would only shuck some rotten apples from the barrel of accumulated knowledge. But the barrel of theory is always full; sciences work with elaborated contexts for explaining facts from the very outset. Creationist biology was dead wrong about the origin of species, but Cuvier’s brand of creationism was not an emptier or less-developed world view than Darwin’s. Science advances primarily by replacement, not by addition. If the barrel is always full, then rotten apples must be discarded before better ones can be added.
Scientists do not debunk only to cleanse and purge. They refute older ideas in the light of a different view about the nature of things.
– Steven Jay Gould, The Mismeasure of Man (351-352)