# Deeply Skeptic & The Simpler the More Complex?
Published: 2026-04-03
Canonical: https://journal.xiaotianfanx.com/journal/deeply-skeptic-and-the-simpler-the-more-complex

On Proof of an External World, G.E. Moore & Skepticism and Inference to the Best Explanation, Jonathan Vogel. Mostly transcribed from speech.





What is the point of Moore's proof of an external world? Is his proof satisfactory or not? Why? 



	Regarding the first question, I have two approaches. The first is quite straightforward: taking Moore’s argument at face value, Moore attempts to prove the existence of an external world, suggesting that the argument itself should be, to some extent, I would say, self-evident (given the simplicity of the argument). He is remarkably candid about how the argument is constructed, his criteria for a "satisfactory" proof, and the potential sources of dissatisfaction. Ultimately, if we accept his premises as true, then it is indeed a satisfactory argument. However, as Moore acknowledges in the lecture, most dissatisfaction stems from the fact that these premises may still be seen as a form of "begging the question" or simply taken for granted.



	Moore's admitting that these premises cannot be "proven" so much as they are "known" leads to my second point: if we adopt an esoteric perspective regarding the purpose of the lecture, we might see another intent of his project. It is possible that Moore intentionally constructed an argument that many philosophers find dissatisfactory, predicting that his premises would be challenged. Especially towards the end of the passage, he may be hinting that because these premises cannot be proven, insofar as he considers them, it is indeed impossible to construct a "satisfactory" argument for the existence of an external world (or at least justifies the persistence of the "scandal") in the strict (general) sense that many philosophers demand. So, if we take his stance as a somewhat esoteric one, then I would even "argue" that essentially, not only is the argument presented not against skepticism, but deep down, it supports skepticism by distinguishing what can be "reasonably asserted" (and thus how other proofs may be constructed upon those assertions) and what can be "proven to be knowledge" in terms of the existence of the external world.





Why does Vogel think the "real world hypothesis" is better than the "minimal skeptical hypothesis" and the "isomorphic skeptical hypothesis" at explaining how your sensory experiences as a whole come about? 



	It seems the reason Vogel considers the real-world hypothesis better than the other two skeptical ones is to think from the perspective of what the just right amount of explanation or extent of explanation we need is to accept a hypothesis, given the framework of inference to the best explanation. Within that framework, according to Vogel, the minimal skeptical hypothesis provides few explanations that are satisfactory to explain what the world would be, even if it were true. While the isomorphic skeptical hypothesis provides too much of an explanation that seems redundant to explain the reality, the real-world hypothesis allegedly succeeds in doing so. 

	



Is the "real world hypothesis" better than the "evil demon hypothesis" or the "dreaming hypothesis" at explaining how your sensory experiences as a whole come about? Why or why not?



	From Vogel's perspective, I would say the dream argument and the evil demon argument are still subject to the simplicity test. Let's say when it comes to inference to the best explanation, at least I would assume that Vogel would think of these two as also more complex arguments that require an external entity or mechanism that explains what we experienced. But I do think the criterion of simplicity here is rather vague and uncertain, even if we do take for granted Ockham's Razor principle, as it seems that Vogel is appealing to. 



	However, in some sense, I would even say that the isomorphic arguments here presented, at least including the computer simulation dream and evil demon argument hypothesis, are much simpler than the real-world hypothesis due to the fact that these three hypotheses give a single solid reason and source of truth or the reason for this world to exist, rather than the real-world hypothesis that explains basically nothing about what is indeed the rule of this world, the natural laws, what the origin of this world is, etc.



	And the fact that the real-world hypothesis brings more questions than a conclusion can be considered some kind of complexity, while the isomorphic hypothesis presented here could be to some extent considered isomorphic to God's existence, as it provides a single source of truth that explains mostly everything about this world, as we can always resort to a single mechanism or entity given that hypothesis. 



	In other words, maybe we should, contrary to what Vogel suggests, favor the real-world hypothesis precisely because of the complexity implied. As no hypothesis (at least those that are presented) would be as complicated as the real world (including the rules and mechanisms within), we are experiencing. In that sense, going back to Vogel's argument itself, maybe the isomorphic hypotheses should also be invalidated, if ever, because the "too-few" explanation they provide is just like the minimal skeptical hypothesis.