Idealism is a metaphysical position that gives fundamental importance to mind, consciousness, ideas, or experience in explaining the nature of reality. Different forms of idealism vary in how strongly they make this claim, but they generally reject the view that reality can be fully understood as purely material. Idealist theories often explore whether the physical world depends upon perception, consciousness, or a deeper mental principle, and they are closely connected with debates about the Mind-Body Problem, monism, dualism, materialism, perception, consciousness, and the nature of substance.