Descriptive scales versus comparative scales

In this paper, I show that scales (or hierarchies) have been appealed to in various functions: They have been used to formulate descriptive generalizations (on a single language), and to formulate cross-linguistic generalizations. They have also been used for binary relations, and for implicational relations among more than two items on the scale. This yields four uses of scales (descriptive relational, comparative relational, descriptive implicational, comparative implicational). I argue that descriptive and comparative scales must be strictly distinguished, because the descriptive categories and the comparative concepts that they are based on are quite different in nature. Description of language-specific facts in terms of scales that are also used for cross-linguistic comparison should be avoided.