One possibility is that lawyers and judges have a tendency, encouraged by early 20th century movements like logical empiricism and American legal realism, to confuse uncertainty with indeterminacy. (See the entry on logical empiricism.) There is often uncertainty about how a provision contributes to the content of the law. Any interesting legal interpretation begins from such uncertainty. If one confuses such uncertainty with indeterminacy, then one will conclude that legal interpretation includes cases in which it is indeterminate how the relevant provisions contribute to the content of the law – and therefore that legal interpretation must not be limited to ascertaining the content of the law.