The Problem with Skepticism

Dystopia Discourse
9 min readFeb 21, 2019


In his ancient classic The Republic, Plato writes his Allegory of the Cave. In this allegory, we learn Plato’s conceptualization of the human condition, which is analogous to people watching shadows being cast on a cave wall, believing those shadows to be reality. Plato describes to us how through the process of acquiring wisdom (philosophy), we can move further and further away from the shadows (ignorance) and closer to the actual outside world that was casting the shadows (truth, reality). However, partly due to the collapse of Judeo-Christian metaphysics in the Western tradition, a new kind of philosophy has appeared in the contemporary period; a philosophy of skepticism. This skepticism seems to call into question any and all claims to knowledge, leaving those who engage with it and are convinced by its arguments, in a sort of agnostic paralysis. To me, this scenario seems to be the reverse of Plato’s allegory. Those who engage with this philosophy and are convinced by it’s arguments are unable to move toward something (wisdom, truth, reality) and instead remain intellectually immobile because of the implications of the metaphysics assumed by these skeptical arguments. In this article I will respond to Peter Unger’s skeptical argument outlined in his book Ignorance, why I feel the foundational premises of his arguments simply do not work, and why where you come down on these arguments is so significant. After I make these arguments, I will attempt to preemptively defend them from potential responses. However, before I can do these things, I must give some background explanation on this topic so that my reader will be able to properly engage with these ideas.

So that one may be able to understand my criticism of Unger’s arguments, and of skepticism more broadly, I must first lay out some background information pertaining to these topics. While we generally think of skepticism as a view that casts doubt on something, according to Dr. Brian Kierland, “a skeptical view in philosophy typically involves more, namely, positive denial of the something in question.” As it applies to the content of this article, I will be focusing on a particular kind of skepticism, namely skepticism about knowledge of an external world. This skepticism regarding knowledge of an external world claims that because no one knows with any degree of certainty that certain skeptical scenarios are false, we cannot lay claim to knowledge about a concrete, tangible, real, external world.

There are a number of different skeptical scenarios that have been laid out over time. I will avoid detailing the specifics of these scenarios (such as the brain in a vat scenario, or Descartes’s evil demon scenario), and instead describe the basic premises that underlay all of these various scenarios. The basic idea of skeptical scenarios (regarding knowledge of the external world) can be approximated as this: you cannot know for sure that the ‘physical’ world you see around you is not an illusion, and that you are not being deceived by some unknowable deceiver (such as a demon, or an evil scientist) via supernatural, or technological means (or some other means). Because no one can know with absolute certainty that this scenario is not happening, no one can claim to have knowledge about the ‘external world’.

Here, we are led to Peter Unger’s skeptical argument that I alluded to at the beginning of this article, which is a well summarized argument for believing the skeptical scenario. It is worth fleshing out in it’s entirety so that I may properly address it:

1. If someone knows that there are rocks, then that person can know that they are not being deceived by an evil scientist into falsely believe that there are rocks.

2. No one can know that they are not being deceived by an evil scientist into falsely believe that there are rocks.

3. No one knows that there are rocks.

4. If no one knows that there are rocks, then no one knows anything about the external world.

5. No one knows anything about the external world.

Now having a substantive template of the skeptical argument on the table, let us take a closer examination of the argument; why I feel we are not justified in believing it, why it’s foundational premises are weak, and what the outcome of these arguments means for us.

The metaphysics that we subscribe to, consciously or unconsciously, determine our ethics. The type of existence we believe we are experiencing decides (or at least greatly influences) how we see the world, who (or what) we give moral consideration to, and how we behave in the world more generally. For example, if we see animals as sentient, thinking, feeling individuals, similar to ourselves, that will inform what (or who?) we eat. If we see animals as meat-robots, that will also inform our dietary decisions. Our metaphysics determine our worldview and our ethics. With this in mind I would like to return to Unger’s skeptical argument. Specifically, I would like to take a closer look at the first and second premises of the argument.

The first premise of Unger’s skeptical argument is a basic if-then statement. However, I do not know if it logically follows that if someone knows there are rocks (are any arbitrary physical object), then they can know they are not being deceived about the external world. I believe the connection between the ‘if’ and ‘then’ of this statement is not entirely clear. Take for example, the movie The Truman Show. In it, Jim Carrey plays a character that has lived his entire life on a studio set, not knowing it is a studio set, and believing it to be the real world. In this movie, the physical world around Carrey’s character (Truman) is real. It is just the people in his life that are fake, along with the city he lives in. Truman can look at the rocks that decorate his fake city and believe to have knowledge of the external world, even though his particular environment is artificial. This metaphysical construction could be thought of as the fishbowl scenario. Some of us choose to keep small artificial fish habitats (fishbowls) in our residence. The fish contained within them may not necessarily know they are not in an artificial habitat for them, yet this artifice is still contained within our physical realm. Were the fish to have a modicum of intelligence, they could look at the rocks, know there are rocks, and claim to have knowledge of the external world. Yet, they would still be deceived by some deceiver about their external world and environment. So, because of this counterexample I am not certain that it can be said that the ‘if’ in premise one necessarily implies the ‘then’.

With my confidence in premise one shaken, I would like to address premise two. My main contention with this premise is that I do not believe we are justified in believing it. To me, it is not rational to posit any potential unknowable metaphysical proposition without good evidence, or cause, and that is exactly what this premise does. It constructs a metaphysics in which our entire reality (including ourselves) is contained in an illusion, in which we are unable to know the falsity of the proposition. If we allow ourselves to accept this mechanism of proposition, we are then forced to entertain all manners of unprovable and frankly absurd notions, and it is a quick race to the bottom of what you would be forced to consider. For example, how do you know whether or not divine Shinto spirits inhabit the wilderness and all living things? These spirits are undetectable to humans, and going by the exact language of premise two, “no one can know that” undetectable Shinto spirits are not inhabiting the natural world. The problem is in this language, “no one can know that”, followed by the insertion of any unknowable and absurd scenario, proposition or notion. The Shinto scenario is just as logically valid as the brain in a vat, or that of the evil demon. No additional logic is required to accept both of them. If we are to truly engage with one of these sorts of propositions in a serious manner, we need to be truly justified in at least considering them. To me, that means having at least some modicum of some sort of evidence.

In addition to the problems I have voiced regarding this premise, being forced to accept all ideas (and potential metaphysical realities) that could spring forth from this reasoning is simply not practicable, and that brings me to my next point; which is what the outcome of these arguments means. To the ancients, philosophy or the quest for wisdom, was a process that moved us closer toward the truth, and dispelled dogma, prejudice and ignorance. This process was the highest level of self-actualization for a person to pursue, and took us individually and collectively, to a better and better place. Accepting the positions of the skeptical argument and the various skeptical scenarios that could arise from this argument would seem to have the opposite effect. They would freeze us in a constant state of unknowing and being utterly confused about the world in which we live. We would be unable to act in a consistent and coherent manner, with our beliefs and doubts about the world in a constant state of flux, if we truly accepted the propositions wrought by this method of reasoning. This is simply not practicable, and it is no way to act in the world. If we accepted the evil demon or evil scientist scenarios, it would lead to extreme nihilism and again, uncertainty about your state of existence.

When it comes to my criticism of Unger’s first premise of the skeptical argument, I am not entirely sure how one would respond in defense. I simply do not see the conclusive connection between seeing something of the external world, and the implication that you know you are not being deceived about the external world because of it. This connection is dubious at best. Perhaps, one defense of this if-then claim is to restate the claim in a revised form. It might look something like this: if someone knows something about a physical object that can be said to be in a ‘concrete’ and ‘absolute’ reality, then that person can know that their reality is not an illusion. This restatement of the first premise avoids the esoteric and complicating language of Unger’s form. Because of the removal of metaphysical propositions, this premise becomes sharper, more tangible and more grounded. With the argument restated in this manner, I am not sure how to effectively respond. Maybe one viable approach to consider is to ask for definitions of concrete, and absolute, in relation to reality. This approach is itself problematic however, because I am generating these terms and then attempting to knock them down.

The path toward preemptively defending my second criticism is clearer. The response to my criticism of the premise would be a claim that my skepticism of this skeptical premise does not necessarily mean that it is not true. That is to say for example, just because we do not have good reason for believing an evil scientist is deceiving us, does not logically entail that it is not true. I believe an effective, but not conclusive response to this would be to invoke Occam’s razor. Occam’s razor is a philosophical principle that claims when presented with two competing explanations of something, the simplest one is often correct. So, what is more likely to be true: a borderline-absurd scenario in which every single thing we experience is an illusion concocted by a demon (or an evil scientist), or that we can trust our sensory and empirical knowledge given that we have no reason to doubt them? The answer is clear: it is more sensible and of a much higher probability that our sensory experience can be trust.

We must be very careful when calling our metaphysical assumptions into question. Tampering with these assumptions and engaging with Pandora's box-type argumentation can lead to a downward spiral of intellectual paralysis or even nihilism. If we do not keep our logic mechanisms rock tight while engaging these sorts of arguments, we may reverse thousands of years of ethical and philosophical progress. Doing so could smother the light of the enlightenment, which was sparked by the great minds of the ancient world. Engaging with philosophy and embarking on the path of moving toward wisdom need not shroud our intellect with infinite doubt and uncertainty about the world, and ourselves.