I agree with Amos. The Unicorn exists as a mental concept the moment you think of it. That doesn't mean it has to exist physically. Existence is not necessarily confined only to the range of physical matter. I have a good "feeling" at the moment about life...and that is not a physical phenomenon...but it is real...within the world of my own consciousness. I submit that consciousness is absolutely real...as consciousness. That's why it's important what you carry in your consciousness at any given time. It tends to affect your interaction with the physical quite profoundly.