As a species we are composed of organic tissue, but none of us would deny the reality of our thoughts, for example, yet a thought is not a physical object like a glass that we can hold in our hands. When we try to examine a thought, we instantly change it. The original thought vanishes, to be replaced by a new one. We can only know what a thought is through our own inner experience.
Neither would we deny the validity of psychological insights or emotions or dreams. These are in no way concrete objects, yet they form an important part of our own consciousness. Such subjective experiences seem to be connected with physical matter, but they do not seem to be literally contained within it.
We say dreams exist “in our heads.” but certainly dreams are not in our heads in the same manner that physical tissue and blood vessels and bones are in our heads. A surgeon can probe into the brain tissue with a scalpel, but no physical examination or operation will disclose s dream or a thought or a psychological experience. No scalpel can cut into a dream as it can pierce the visible fibers inside our bony skulls. Then what do we actually mean when we assume that dreams and thoughts are inside our heads?
The idea is based on the assumption that the human personality is limited by physical matter and held in bounds by the physical self. Therefore, anything belonging to the personality would have to exist within the physical organism. If we are purely physical creatures, then, we would still have to admit that we contained some things that were not physical; otherwise these thoughts and dreams inside of us would have to be physical also, and they are not.
Scientists have theorized that consciousness may be the result of the ways in which the body operates. Even if this were the whole story, and I do not believe it is, then we would still have to admit that part of our reality was not physical, but was born out of physical matter and could not be seen and touched. Nevertheless, because of this attitude we have the idea that reality is determined by physical existence only. (We consider valid only those things which can be judged so by the physical senses.)
It seems to make no difference that physicists have discovered that the senses themselves distort reality, and that we merely create patterns out of atoms and molecules, perceive these as objects and give them names. In general we still act as of physical reality were the only standard by which to measure experience.
We can hardly refer to something which affects us deeply as unreal. We can say that an experience exists in some perspectives and not in others. Many dreams are as vivid as any waking experience, for example, and have as great an effect upon our personalities. The dream may not have a physical reality but it certainly has a psychological reality.