So basically it is just an argument against phenomenalism, nothing else. Experience is not evidence, and lack of experience is not lack of evidence. This should be clear and established.
So this has nothing to do with existance or evidence. Only an arguement against phenomenalism.
http://en.wikipedia.org/wiki/Phenomenalism
In the philosophy of perception, phenomenalism is the view that physical objects, properties, events (whatever is physical) are reducible to mental objects, properties, events. Ultimately, only mental objects, properties, events, exist. In particular, we may reduce talk of physical bodies to talk of bundles of sense-data.
The philosopher who is most famous for advocating both the bundle theory of objects, and phenomenalism, is the 18th century Irish philosopher, George Berkeley. Berkeley's version is more commonly called "subjective idealism".
Philosophers who hear the sceptic's challenge - "There's no reason to think an external world exists" - reply, "Well, no, I guess there isn't any reason to think that an external world exists. All there is, is sense-data. Physical objects are bundles of sense-data. When I hold up my hand, and I see it, I'm not seeing something external to my mind; I'm seeing a series, a whole bundle, of hand sense-data, and there is no hand apart from those hand sense-data. That's what my hand is - a bundle of sense-data." Such philosophers get around scepticism not by replying to the sceptic and proving the existence of an external world, but instead by saying that there is no external world.
