Indeed. In Dimensio's case, it appears to be a methodological bias (i.e., "methodological naturalism" or even "metaphysical naturalism"). But the one so biased rarely questions the adequacy or suitability of the method to the given question at hand. It is simply assumed the method is competent; that is, the method is simply taken on faith. Oftentimes it ends up being a filter that, as you say cornelis, "bars evidence and frames the debate."
The the motive for a "methodological naturalism" is in some instances warranted. There is an analogous method taught in literature classes, which the famous poet John Keats called "negative capability." It has something to do with suspending judgment for the sake of being open to observation. I guess the problem is that scholars get stuck in their method being so happy with their success. This is not particular to scientists. This is a habit of the mind, a particularly nasty one.