Proof of an external world

[Hnv1]

I always considered my self a Kant advocate and I just read G.E. Moore's essay (by the topics name) which I found interesting.
On one hand the common sense of his proof is undeniable, from 'here is a dog' it does follow 'there one thing in space hence there is an external world' though I feel there is a problem with being able to say 'I know' there is a dog there. Moore claims we cannot provide an evidence for out knowledge and any attempt will be futile but I feel modern science is actually proving Kant's theory that the external world is a thing in itself (ding an sich).

Thoughts? Can there be a proof for knowledge? is common sense enough to claim assertions regarding the external world?

[DemPGH]

I can't comment on the Philosophy since it's neither my cup of tea nor my expertise, and I tended to stay away from it, but yes, there is an external world with objective reality. If not, then nothing would make sense; as such, experiments are probably the highest form of evidence. I guess the point I would make is that the fact that our understanding of everything is significantly better than it was before, or perhaps that it has has changed, should not be confused with the notion that there is no external world, objective reality, or that it's limited, et. al. We're only discovering it. That takes time and error.

[Associate Justice PiT]

     As I recall, Kant maintained that the thing in itself was unknowable. Claiming that there is proof of external reality seems to contraindicate Kantian philosophy.

     Besides, the rejection of objective reality is rooted in a skepticism about the nature of human knowledge. While you are welcome to deny the validity of that skepticism, appealing to experimentation as proof of external reality does not address the substance of the argument.