 G2D is a strategy for defending a variant of this traditional view of meaning against a series of influential objections. In the 1970s and 80s, semantic externalists used a variety of persuasive examples to argue that the traditional account of meaning yields an unrealistic picture of (i) semantic competence, (ii) reference determination, and (iii) epistemic access to modal facts. Proper names and natural kind terms seem especially problematic for the traditional  account.[9]  By commonsense standards, you don’t need to know a specific rule for identifying Gödel in any possible world in order to count as competent with the name ‘Gödel’; and no such knowledge seems required for your use of the name to pick out the relevant man in every possible world (Donnellan 1970; Kripke  1980).[10]  Similarly, you don’t need to know precisely what it takes for something to count as water in any possible world to be competent with the word ‘water’ or for your word to pick out the chemical substance H2O in every possible world (Kripke 1980; Putnam 1970, 1972). Indeed, making room for the possibility of ignorance and error about reference-conditions seems crucial to explaining empirical inquiry into the nature of familiar things, and to vindicating the commonsense realist idea that we can refer to things whose nature we don’t fully understand (Burge 1979, 1986; Putnam 1972, 1973). If these critics are right, then the traditional account of meaning is untenable. Implicit knowledge of reference-conditions is not required either for linguistic competence or for determinate reference. And apriori conceptual analysis cannot be trusted to reveal what’s genuinely possible—at best, it reveals one’s current fallible assumptions about the topic in question. [See the entry on  externalism about mental content.]