Classical physicalism, which is the doctrine in which the physical world is taken to be the only real world, has not provided a plausible account of consciousness. Consciousness experience is as mysterious as it is familiar. This is because although we feel consciousness as the most direct experience, we can ever have but we cannot describe it with an objective viewpoint. It means we cannot account it with any other things we used to interpret other natural events. Here we should differentiate between brain activities, that we can know about them objectively, and consciousness as a first-personal and subjective experience.