Conference “Natural Kinds: Language and Metaphysics”, 15-16 March 2018 | Madrid, Spain
If we decided to call both – H2O and XYZ – “water”, would “water” be ambiguous? And calling both – jadeite and nephrite – “jade”, is “jade” ambiguous? Although it might be difficult to answer the first question since we haven’t “discovered” Twin Earth yet, looking at different periods in Earth’s history, we see that the answer to the second question was not always the same. The important insight is that the border between natural kinds is flexible: new knowledge may shift our view of the borderline. But, in my opinion, that doesn’t mean that naming of natural kinds is a result of “sheer contingencies” nor that ambiguities appear arbitrarily. Two factors influence the baptism of natural kinds, (i) our empirical knowledge of reality and (ii) our decisions in the course of the naming process. I am going to throw light on the question where ambiguity can arise.