Also, while we may not be able to prove our own existence, since we can be written off as your imagination, one [i]can [/i]prove their own existence to themselves. The saying "i think, therefore i am" works, because the fact that you can recognize your own thoughts (self awareness), means that there is at the very least a Consciousness to think of those thoughts. This consciousness is all that can be proven with that statement, but that consciousness is also all you are. Wether you have a body or not is irrelevant, as "[i]You[/i]" is an entity, defined only by the parameters that can be recognized as it.