Some theories make me feel like a square headed skeptic, and the more I read the less sure I am about my square headed convictions, but I don’t have that doubt about Berkeley’s philosophical theorems. If you ask me Berkeley was not a philosopher, he was a salesman. He wished to prove the existence of his product (God), which could not be seen, heard, smelled, tasted, or touched – so he was compelled to refute the existence of anything that those five senses were able to detect. I don’t see why the problem of tangible existence has taken so long to refute, aside from the general obsession humans seem to have with supernatural perceptions. It seems to me that the problem is fairly simple.
If an object exists, then by logical extension there is something that cannot exist where the object exists: empty space. When Johnson kicked the rock, he proved the absence of empty space where he ‘perceived’ the rock. He wasn’t alone – there was a witness – so the possibility that he imagined the whole thing is far-fetched. Our senses might not be perfect, but once an object has been proven to exist it is a simple, logical process to identity it’s characteristics as best we can with our percepting skills and agree on a name. I also think it’s a simple problem to prove an object’s existence outside of my perception. If I leave a rake in my garage, anyone can enter my garage and perceive the rake. In fact, anyone entering the garage and looking all around the room would be compelled to perceive the rake if I left the remainder of the garage empty, assuming the most basic human senses were available to them.
Bob Gregory's Gallery of Renown 