This chapter analyses the ICJ Statute Article 38(1), interpreting each its component terms, with a particular emphasis on ‘teachings’. One overall conclusion is that the wording of Article 38(1) gives at best limited on guidance on the application of teachings, which supports the utility of the examination made in the rest of the book. When interpreting ‘teachings’ specifically, it is particularly difficult to classify works produced by the International Law Commission. They are not seen as ‘teachings’ in the book.