Knowledge ascriptions, such as 'Sam knows that Obama is president of the United States', play a central role in our cognitive and social lives. For example, they are closely related to epistemic assessments of action. As a result, knowledge ascriptions are a central topic of research in both philosophy and science. In this collection of new essays on knowledge ascriptions, world class philosophers offer novel approaches to this long standing topic. The contributions exemplify three recent approaches to knowledge ascriptions. First, a linguistic turn according to which linguistic phenomena and theory are an important resource for providing an adequate account of knowledge ascriptions. Second, a cognitive turn according to which empirical theories from, for example, cognitive psychology as well as experimental philosophy should be invoked in theorizing about knowledge ascriptions. Third, a social turn according to which the social functions of knowledge ascriptions to both individuals and groups are central to understanding knowledge ascriptions. In addition, since knowledge ascriptions have figured very prominently in discussions concerning philosophical methodology, many of the contributions address or exemplify various methodological approaches.The editors, Jessica Brown and Mikkel Gerken, provide a substantive introduction that gives an overview of the various approaches to this complex debate, their interconnections, and the wide-ranging methodological issues that they raise.