 Ruth Millikan and David Papineau were the first to offer teleological theories of content that put a strong emphasis on how mental representations are used within a system. In this section, we will mainly focus on Millikan’s ‘biosemantics’, as her theory is often called, while Papineau’s account will be the subject of the next section. Millikan presents her view in great detail in her (1984) and develops it further in her (2004) and (2017, part II); compressed versions are provided in her (1989b) and (2009).