I am currently reading '<a href=http://www.randomhouse.com/crown/catalog/display.pperl?isbn=1400080797>The Quantum and the Lotus</a>' , a very good book. It talks about the convergence between modern scientific theory and Buddhist philosophy.
One of the passages talks about how reality is an illusion, and how we collectivity determine what reality is. Now this has interesting ramifications. For example, if you were to live in a culture where everyone believed in pixies, then perhaps they would actually exist, as far as that culture extended.
How can that be?
I will take a example that they used in the book, and expand on it a bit.
Say, that you are a person living on an island in a river. To one side, there is a farmhouse, and to the other side there is a copse of trees. There is a rainbow above, that stretches from the farmhouse to the copse of trees.
From your perspective, being confined to that island , would it not be easy to believe that the rainbow comes from the farmhouse and stretches across the sky, and your entire universe, to the copse of trees? What sort of belief structure would you come up with? Would you venerate the farmhouse and trees? What would you feel about the little figures that you could see living in the farmhouse?
Now, say, you were plucked off the island, and placed into the farmhouse's front yard. Would the experience live up to the beliefs? Where would the rainbow be , that you had seen coming from the farmhouse? What would that do to your world view and beliefs?
Reality really depends on the observer. A cat, dog, insect and human have radically different views of what reality is. Is any of their views less probable, or less real then ours? How about the world view of a bat, that only sees thought reflected sound?
I propose that what we call reality is in fact a convenient illusion, created in part by our minds to deal with the world around us, and in part created by the collective beliefs of all of us to provide a common frame of reference to enable communication.
Reality is taught to us by our community and our parents.