The Neurotic Dogma of Reality

The world appears to be a certain way, but sometimes appearances are deceiving. This doesn’t seem to undermine what we think we know, for instance, the apparently obvious fact that we have hands. But, how do you know you’re not dreaming right now? Or better, do you know you’re not a handless brain in a vat living in a simulation? An old argument goes as follows:

(1) If you are in a position to know that you have hands, then you are in a position to know that you are not a brain in a vat (BIV).

(2) If your evidence to believe that you’re not a BIV isn’t any better than your evidence to believe that you are a BIV, then you’re not justified in believing that you’re not a BIV.

(3) Your evidence is the same for both cases.

(C) You are not in a position to know that you have hands.

The first premise assumes that your epistemic position is closed under entailment, that is, if you’re able to know that p and you can deduce q from p, then you’re able to know that q. Premise (2) claims that justification isn’t underdetermined by evidence, that is, if you’re justified in believing that p then you have more evidence for p than for any proposition incompatible with p. Finally, the third premise states that your evidence is the same for the good and the bad case. With these premises, and the background assumption that knowledge requires justification, our conclusion (C) follows. The same applies, mutatis mutandis, for pretty much any empirical proposition. This generalization is known as ‘skepticism.’ So, shall we all be skeptics of the external world?

While the skeptical argument might seem intimidating, there is a popular response known as ‘dogmatism’ (Pryor, 2000) which dates back to the British philosopher G.E. Moore. According to the dogmatist, justification is cheap. We are justified in believing the contents of our sensory experience provided that we don’t have good reasons against this. In other words, being entitled to follow what experience tells us about the world should be the rational default approach. Importantly, dogmatism claims that the justification we get from perception is immediate, that is, it doesn’t depend on our justification to believe any other proposition. So, we can reject premise (2) of the skeptical argument.

But dogmatism remains silent on a very important question. What is it about ordinary perception that provides us with immediate justification for our ordinary beliefs? One suggestion is to appeal to the sensory mode of representation associated with perception. But this doesn’t help much since other mental states represent in a sensory manner and typically don’t provide immediate justification, for example, mental imagery (imagining that p doesn’t give you a reason to believe that p). Another common suggestion is that ordinary perception is veridical (i.e., it represents the world as it is) or that it at least maintains the appropriate causal relation with the external world. Nevertheless, this doesn’t help either because hallucinations lack this feature and they seem good enough for immediate justification (e.g., the brain in a vat is in a constant hallucinatory state). Thus, sensory representation isn’t sufficient, and veridicality isn’t necessary.

At this point, the skeptic has a way to push back against the dogmatist with what I call ‘the immediate epistemic question’ (IEQ): what is it about ordinary perception (and not mental imagery) that provides you with the alleged immediate justification?

IEQ is a notably hard and deep question, it’s basically the question of what distinguishes, from an epistemic point of view, dreams from reality. The question is also of considerable importance for computer science considering the recent attempts to develop better virtual reality engines. However, the issue isn’t entirely new, it has been around at least since the Early Modern Period. It was at the heart of Descartes’ Meditations. One suggestion that we can find in contemporary epistemology (though we can also find it in Hume) is the claim that ordinary perception has a phenomenological property that presents its content with a certain force and is responsible for our sense of reality (Pryor, 2000; Huemer, 2001; Smithies, 2019). This is called ‘phenomenal force’ (or ‘presentational force’) and is the property in virtue of which perception presents its content as true and directly available to the subject. So, we can think of this feature as the phenomenal property of seeming to be true or seeming to be present.

Another helpful way to understand phenomenal force is by contrasting mental states that have it (e.g., ordinary perception and hallucinations) with mental states that typically lack it (e.g., mental imagery, dreaming, beliefs, memories). Importantly, with the concept of phenomenal force on the table, we have an answer to IEQ. We might call this answer ‘epistemic phenomenalism’ (Berger et al., 2018). According to this view, phenomenal force is both necessary and sufficient for immediate justification.

However, there are reasons to doubt the sufficiency claim. For instance, it seems that some states of mind-wandering like episodes of daydreaming have phenomenal force even though intuitively they don’t justify what they represent (Teng, 2018). Nonetheless, in the light of this counterexample, the necessity claim is still very informative, it tells us what experience should be like if dogmatism were to be true (it requires phenomenal force) and it explains why mental imagery lacks justificatory power (it lacks such a force). So, are we done with IEQ?

Not yet. At this point, it’s worth looking beyond the neurotypical realm because there we can find examples of sensory diversity. In particular, there is a condition known as ‘derealization’ (aka depersonalization) in which sensory experiences are described as dream-like. This condition sometimes obtains as a consequence of generalized anxiety, PTSD, OCD, or major depression. The DSM-5 classifies derealization as a dissociative disorder (F48.1) and describes the conditions as follows: “Experiences of unreality or detachment with respect to surroundings (e.g., individuals or objects are experienced as unreal, dreamlike, foggy, lifeless). During the depersonalization or derealization experiences, reality testing remains intact” (American Psychiatric Association, 2013, p. 302). By ‘intact reality-testing,’ psychiatrists mean that derealized people aren’t psychotic (they are just neurotic). They don’t experience hallucinations, they are rather perceptually reliable and navigate the world normally.

I think that cases of derealization provide a counterexample to epistemic phenomenalism since they show phenomenal force isn’t necessary for immediate justification. In particular, the case of derealization supports three claims that together refute epistemic phenomenalism. First, that derealization is a condition characterized by the absence of phenomenal force. Second, sensory experiences in derealization justify belief. Third, the justification they provide is immediate.

To argue for the first claim, we just need to look at the reports from derealized subjects. They describe their ordinary sensory experience as a dream or a faint memory. Everything looks objectively the same but subjectively downgraded. Importantly, mental states that fit those descriptions are precisely those that lack phenomenal force, for example, mental imagery. I can confirm that those testimonies are true because I have experienced derealization myself.

To argue for the second claim, we can point to the fact that they have a conscious experience that provides evidence in favor of a certain proposition. In particular, they aren’t like people suffering from blindsight (a neuropsychological condition in which subjects can make basic perceptual decisions in the absence of phenomenology). Finally, in defense of the third claim, we can reason as follows. Derealized people are disposed to form beliefs and behave normally based on their forceless experiences. If they were not immediately justified based on their forceless experiences, those beliefs and actions would be presumably irrational. However, they aren’t irrational. Thus, they are immediately justified on the basis of their forceless experiences.

Now, why assume they aren’t irrational? A prima facie reason is that they are—more or less—behaviorally indistinguishable from neurotypicals. In addition, we can think of a congenital version of derealization and ask whether these subjects would be irrational in holding neurotypical beliefs and acting normally. The answer again seems to be negative. So, we can get immediate justification in the absence of phenomenal force. From this, it follows that epistemic phenomenalism is false.

What now? Unfortunately, without epistemic phenomenalism, we are back to the beginning. Although we can appeal to dogmatism to reject the skeptical argument, without an answer to IEQ our response appears somewhat arbitrary. One suggestion could be the following. Perhaps it’s just a brute fact that conscious perception has this epistemic power. We simply can’t go any further. But as some philosophers have pointed out, this makes immediate justification a mystery (Markie, 2005). Or, perhaps, it’s time to admit that we still have no good answer to the skeptical challenge.

Edvard Aviles-Meza

Edvard Avilés-Meza is a third-year philosophy Ph.D. student at Cornell University. He works mainly in the philosophy of mind, epistemology, and everything in between (especially through the lens of cognitive science).