What are the main differences between metaphysical idealism and epistemological idealism?

In philosophy, idealism is a broad tradition that emphasizes the central role of the mind or spirit in interpreting experience. The two primary forms of idealism differ in their focus on the nature of reality versus the nature of knowledge:1

• Metaphysical Idealism: This view asserts the ideality of reality itself. It posits that the world exists essentially as spirit or consciousness, or that abstractions and mental laws are more fundamental to reality than physical, sensory objects. In this sense, it stands in direct opposition to materialism, which argues that matter is the basic substance of the world.1

• Epistemological Idealism: This form focuses on the process of human knowledge. It holds that the mind can only grasp what is psychic or that the objects of our knowledge are fundamentally conditioned by their perceptibility. It is opposed to realism, which maintains that we can perceive objects as they exist independently of the mind.1

While these categories define the scope of idealist thought, philosophers like Immanuel Kant developed nuanced positions, such as transcendental idealism, which suggests that while the mind structures our experience of the world, it does not necessarily deny the existence of a reality beyond our perception.2