Since Timothy Williamson published his influential book Knowledge and Its Limits in 2000, the "Knowledge First" theory has become a hot topic in the past two decades and is generally considered to be one of the most important innovations in contemporary epistemology. Williamson opposes and discontinues traditional knowledge analysis (conceptual analysis of knowledge into belief, truth, and justification or other elements), and advocates that knowledge is basic and cannot be conceptually analyzed. We should take knowledge as primitive and core, and use knowledge to understand other epistemic concepts such as belief, justification, evidence, etc. Williamson's theoretical image has been widely echoed, and there are various ways to participate in knowledge-first programs. In addition to in-depth exploration of the basic issues of the knowledge first theory itself (including defending its theoretical advantages, opposing its key elements, etc.), this course will also follow the hot and developing applied topics published in recent years, including virtue epistemology, New Evil Demon Problem, Sustaining Rules, Preponderance of the Evidence, etc., discuss and extend the development of these important emerging research directions in epistemology.