  A second influential proposal for dealing with the difficulties left pending by the information-theoretic approach and for showing that some non-mental things can exhibit intentionality has been Ruth Millikan’s (1984, 1993, 2000, 2004) teleosemantic approach. Millikan’s teleosemantic approach rests on two basic assumptions, the first of which is that (unlike a natural sign) an intentional representation is a relatum in a three-place relation involving two mechanisms: a producer of the representation and a consumer, both of which are cooperative devices whose activities are beneficial to both. Millikan’s second assumption is that Brentano’s relation of intentional inexistence is exhibited by biological functions. Given any sort of biological purpose or design, it might fail to be fulfilled. For example, if it is the function or purpose of a mammal’s heart to pump blood, then a mammal’s heart ought to pump blood even though it might fail to do so. Notice, however, that whereas biological organs have functions that may fail to be fulfilled, they do not ipso facto exhibit intentionality in Brentano’s full sense: neither a heart nor a stomach are of or about anything. Millikan’s claim, however, is not that having a function is sufficient for aboutness, but that it is necessary. Arguably, a device cannot be about or represent anything unless it can misrepresent what it is about. Presumably, for a device to misrepresent what it is about is for it to misfunction. But unless the device had some function, it could simply not misfunction. If this is correct, then nothing could be a representational system—nothing could have content or intentionality—unless it had what Millikan (1984) calls a ‘proper’ function.