Moving on into the solidly 20th century topics of Castle's collection of essays, the framework of interpretation shifts. When people wrote or left evidence of their lives prior to the development of modern categories and vocabulary around lesbian identity, the work of trying to connect those lives with concepts of identity is necessarily difficult. That difficulty may include deliberate obfuscation, either by the subjects themselves or by those writing about them, but it may also simply involve a lack of clear and explicit language.