In the second half of the 20th century, Stephen Toulmin argued that the need to distinguish between reality and appearance only arises within an explanatory scheme and therefore that there is no point in asking what "ultimate reality" consists of. More recently, a similar idea has been suggested by the postanalytic philosopher Daniel Dennett, who argues that anyone who wants to understand the world has to acknowledge both the "syntactical" aspects of reality (i.e., whizzing atoms) and its emergent or "semantic" properties (i.e., meaning and value).