The problem of universals is an ancient question from metaphysics that has inspired a range of philosophical topics and disputes: "Should the properties an object has in common with other objects, such as color and shape, be considered to exist beyond those objects? And if a property exists separately from objects, what is the nature of that existence?"

Metaphysics is the branch of philosophy that examines the basic structure of reality. It is often characterized as first philosophy, implying that it is more fundamental than other forms of philosophical inquiry. Metaphysics is traditionally seen as the study of mind-independent features of the world, but some modern theorists understand it as an inquiry into the conceptual schemes that underlie human thought and experience.