 The conceptual analyses produced by this method count as apriori, according to the 2D empiricist, because you can know them to be correct “independently of knowing what the actual world is like” (Jackson 1998a, 51). The evidence that supports such analyses consists in purely hypothetical judgments: judgments about how to classify cases on the supposition that your environment is like X, or like Y. Since such hypothetical judgments don’t require you to determine what your real environment is like, your justification for accepting an analysis is not based on empirical knowledge. And to change your judgment about a purely hypothetical case would be to change the meaning of your term (Jackson 1998a, 44–46).