In his essay “Proof of an External World”, Moore begins by saying that there are many perfectly rigorous proof and arguments for the existence of an external world. The example he gives is suppose he holds up his left hand and says, “here is a hand”; then he holds up his other hand and says, “here is another hand.” Moore argues that this is a rigorous proof of the conclusion there now exists two hands at this point in time. For any proof to be considered rigorous, you just need the following three things: (1) the premises must be known, (2) the conclusion must be different than the premises, and (3) the conclusion must follow from the premises (i.e. if the premises are true, so must the conclusion). Moore claims that his hand proof is rigorous, and he thinks it should be obvious that many more proofs like this can be given. However, his proof that the external world exists relies on the assumption that we know that “here is a hand”. The fact that the premise itself is not rigorously proved is much cause for skepticism; yet, Moore tries to show that the skepticism is unwarranted. We cannot necessarily prove that we can know the world exists, but we still can in fact prove that it exists by a similar procedure to Moore’s hand argument. While I feel that Moore is correct, looking at his position from a skeptic’s standpoint is hardly convincing. His argument does not seem to have an effect on the skeptical position except appealing to common sense. He simply says that we can know without being able to prove that a certain knowledge of something (i.e. the hands existing) is possible.