 This passage highlights several features of Carnap’s logical pluralism and philosophy of logic more generally. It seems clear that he intended his logical pluralism to be both ‘horizontal’—that is, to allow for different logics at the same level, such as classical and intuitionist sentential logics—as well as ‘vertical’—allowing for logics for new kinds of expression, such as intensional logics and second-order logic (the terminology is from Eklund 2012). Furthermore the passage expresses a “logic-first” approach, and rejects a “philosophy-first” approach, suggesting that rather than trying to figure out which is the best logic a priori from first principles (the ‘philosophy-first’ approach), we should let logicians develop languages as they like, and then make our judgements based on how things turn out. 