This book features original essays on knowledge and rationality as related to the work of Stewart Cohen. This is the first volume dedicated to Cohen, one of the most influential epistemologists of the last several decades. Stewart Cohen is responsible for introducing the New Evil Demon problem, the problem of easy knowledge, and epistemic contextualism. Any one of these contributions is sufficient by itself to establish a lasting philosophical legacy. The chapters in this book reflect Cohen’s legacy and address a variety of important topics related to his work, including the New Evil Demon problem, epistemic justification, epistemic contextualism, pragmatic and moral encroachment, epistemic obligations, skepticism, and the problem of easy knowledge. The book also includes a complete bibliography of Cohen’s works. Knowledge and Rationality is an essential resource for scholars and advanced students in epistemology with an interest in engaging with Stewart Cohen’s philosophy.