Defining and explaining culture. Comments on Boyd and Richerson Not by genes alone. Dan Sperber and Nicolas Claidière. Biology and Philosophy 2008 23(2): 283-292.We argue that there is a continuum of cases without any demarcation between more individual and more cultural information, and that therefore “culture” should be viewed as a property that human mental representations and practices exhibit to a varying degree rather than as a type or a subclass of these representations and practices (or of “information”). We discuss the relative role of preservative and constructive processes in transmission. We suggest a revision of Richerson and Boyd’s classification of the forces of cultural evolution.