Centered around our knowledge of mathematical, modal, and a priori truths, this is a collection that celebrates the work of Keith Hossack, who, throughout his career, has made outstanding contributions to the theory of knowledge, metaphysics, and the philosophy of mathematics. Starting with a focus on our knowledge of abstract entities such as mathematical objects and the source of the necessity of mathematical truths, attention moves to the notion of necessity and its interaction with a priori knowledge: Is it the case that a proposition is necessarily true precisely when it is known a priori? Coverage concludes by zooming out to offer new perspectives on the theory of knowledge: What is knowledge? Is knowing a relation between an agent and a fact? How can we explain rational ignorance by a theory of content? How can we know the content of our own minds, and what does it tell us about the role of a priori knowledge? Featuring chapters by colleagues and students of Hossack’s, a team of contributors that includes established philosophers and up and coming academics, Knowledge of Truths in the Philosophy of Mathematics represents some of the most vibrant discussions taking place in analytic philosophy today–