The subjective, on the other hand, tends to be pejoratively identified with the imaginary and the merely personal, private, or interior. Realism holds that the physical world presented to us in experience as out there, solid, and real, is what truly exists. Through interactions with the nervous system, the world outside the body impinges upon it, initiating complex material reactions within the body's brain, leading to objectively observable behaviour but also to subjective experience. We are tempted to imagine the subjective as occupying a pseudo-material existence along side the physical, and try to ponder the interactions between them. In contrast, idealist world-views hold that the material world is not real, but a creation of the mind.
Mind becomes primary and causative, matter becomes secondary and illusory.
Both the materialism of science and the idealism of spiritual traditions have sought the eternal and changeless beyond the realm of experience, but have pursued diverging strategies. Science looks for unifying principles behind the diversity of sensory experience by eliminating the subject of that experience as irrelevant. We erroneously think we are the body, identifying with its perspectives and priorities. And from the body's point of view, there is an external reality which holds sovereignty over its priorities, since the body's very existence is part of that reality and contingent upon processes within it. Hence the widespread belief in our culture that mind is at the mercy of the brain, an organ of the body, which is a function of the world.