[Topics: Assumption, Evidence, Skepticism, Belief]
The Least Assumptions:

Cartesian Skepticism, and Reducing Guesses and Assertions in a Belief Network to the Minimum


Portrait of René Descartes after Frans Hals - beliefs, minimizing assumptions

Portrait of René Descartes (based on the painting by Frans Hals)


I closed the examination of pragmatic ethics in the previous article by saying that this time I would talk about “the one and only sense in which it is reasonable to maintain skepticism of the external world.” So I’m going to do just that. But before reaching that explanation, I need to make a few remarks about why it is important to minimize assumptions when forming beliefs. After all, prior to saying that universal skepticism is not generally as useful or compelling as it seems, I’d like to first make it clear that skepticism in general is a vital and healthy part of one’s intellectual life.

As René Descartes famously observed, it is always striking how very much of what any given person claims to know (and so believe) rests upon a network of baseless or near-baseless assumptions, assertions, and heuristics so densely matted together that the person fails to realize that there is no actual solidity to its foundation whatsoever. An important feature of this nebulous nest of guesses and half-considered notions is the redundant and overlapping (if occasionally contradicting) nature of its constituent elements. It is just such a nest to which I aim to provide a superior alternative.

But where do we draw the line? There are folks online (like Eliezer Yudkowsky) who have built a serious following out of espousing fervent adherence to certain forms of skepticism and rationality. So, am I in support of such efforts, or against them? That, too, I will answer in the course of this article.

Assumption-Nests and René Descartes:

Just as the removal of a single twig or even a whole host of twigs from a bird’s nest will fail to compromise the structural integrity of the nest, so this mental nest can stand to sacrifice multitudes of assumptions in the face of legitimate criticism without dropping its insulated beliefs (i.e. its illusory knowledge). This sort of nest of assumptions is a comfortably versatile bed on which to rest beliefs which are convenient or agreeable, but which may not be defensible when proceeding only through reason and building with one fact at a time. Indeed, assumption-nests are often so messy and so tightly crammed with erroneous notions that they conceal from even the nests’ constructors the simple fact that there are no eggs within.

Human beings should be able to do considerably better than birds. Rather than just forcing together any random elements and hoping that they are smashed together in such a way that they will not be soon destroyed, humans can come to an understanding of the materials at their disposal; can analyze the conditions which their constructions will need to meet; and can build a proper structure. (Even if the goal is to incubate an egg and raise a baby bird, the human can improve on the design.) By comparison, the nest may be more malleable—and so resistant to piecemeal testing—but it is ultimately flimsy, in danger of being toppled by a light breeze or crushed by nature.

Crow Nest (Emőke Dénes) - René Descartes - beliefs, minimizing assumptions

Photo by Emőke Dénes

Humanity’s physical outstripping of rudimentary construction should be matched by a mental outstripping of rudimentary belief. This is not to say, however, that unassailable beliefs can be found; any blueprint of a work of architecture is capable of being altered or improved in some way, and some seemingly sophisticated constructions can later be torn asunder by mistakes made in the design, or mistakes made when building, or unexpected scenarios arising.

The obvious question which follows all of this would be, ‘How would one find out which of their beliefs are well-founded, and which are faulty?’ This question can be answered in a number of ways. René Descartes provides one promising and immensely influential path: the first thing to notice is that a cursory confrontation of an existing belief might fail to reveal its insufficiency.

Confronting an existing belief lightly or conservatively would be like wanting to test the aforementioned bird’s nest without dropping (or, for that matter, seeing) the believed-in eggs. One begins pulling twigs out here and there and, after filling one’s hands and pockets with twigs without toppling the nest, one can pat oneself on the back and declare the belief’s foundation appropriately strong—generally followed by replacing the removed twigs, for future tests of a similar description.

The first concern of a human being who intends to claim that they know anything at all must be to think in a more radically simple way. If one imagines two versions of oneself simultaneously, one version as the thinker is now and one version stripped of every single scrap of knowledge except for rationality and sensory capabilities, what, if anything, could the former convince as true to the latter? Careful and simple methods of doubt and reconsideration like this one are some of Descartes’ greatest legacies. Thus Descartes writes:

[. . .] even if I cannot abstain from errors [. . . by having] evident perception of everything concerning which one must deliberate, nevertheless I can do so by [. . .] remembering that whenever the truth of a given matter is not apparent, I must abstain from making judgments. Although I observe that there is in me this infirmity, namely that I am unable always to adhere fixedly to one and the same knowledge, nevertheless I can, by attentive and frequently repeated meditation, bring it to pass that I recall it every time the situation demands; thus, I would acquire a habit of not erring. (Descartes 432)

The Least Assumptions and the Nature of Evidence:

I, like many thinkers before me, am much more impressed by René Descartes’ first two meditations than by the meditations that follow. There are valuable insights in the later sections (such as the quote that closed the last section, which is drawn from the fourth meditation), but the primary arguments of the later portions seem to me to be riddled with issues. The problem with leaving it at that, of course, is that agreement with only Descartes’ first two meditations, with no further thought, leaves a person mired in radical skepticism. Being thoroughly skeptical of any possibility of knowing about external reality is a prospective end to the conversation, as well as a prospective end to all thought of existence (in the existential, contextualized sense of the word).

So, for this reason, we should seek solace in the work of a later philosopher: Immanuel Kant. Kant argues that the only ‘external world’ that we don’t know about is the world as it is in itself, which is to say the world entirely separated from human cognition. And we don’t simply not know about it—we can never know about it. But if, when we say ‘external world,’ all we mean is the world as it is represented to us by our senses and our understanding, then Kant contends that we have no reason to doubt it whatsoever; the world as it appears to us is as well known to us, he argues, as is our own mind. We learn about it through experience, through science, through books. It is represented by us according to universal categories and laws of the understanding, and is therefore an objective world despite its dependence on the experiencing subject.

Armed with this clarification, now you are equipped to see what I mean by saying that my quest to reduce doubtful assumptions in my mind is tied up with a pragmatic and phenomenological point-of-view. As the world as it is in itself, apart from my perspective, is something that I will under no circumstances ever have any access to, I am (pragmatically) content to limit my world to the one in which I (phenomenologically) seem to be living. After all, that’s the one I care about; it contains my friends and family and every memory I have. I have previously expressed this point by simply saying that I hold to no metaphysical assumptions whatsoever. I think either expression paints a fairly accurate picture of my outlook.

You can see, however, that it would still be possible to say that, with respect to the world as it is in itself, I am a radical skeptic. After all, I am saying that there is a sense in which it is reasonable to be skeptical of the external world—that sense being the one in which we will categorically never have access to things as they are in themselves, apart from our experience. But I still think it would be fairly misleading to label me a radical skeptic. After all, I’m not saying the world as it is in itself doesn’t exist (in fact, Kant argues that it surely does); we just don’t know anything about it. But the world as it appears to us? That one both exists and we know quite a lot about it (more every day, in fact). Thus, it’s the only one I usually talk or think about, and, if asked whether I think the external world exists, I would hold that one in my mind as I emphatically answer in the affirmative.

Taking that as a foundational position, however, I endeavor (as Thomas Nagel counsels, in regard to the experience of absurdity) to retain my irony and lack of full commitment to that position. After all, I still earnestly desire to rout my beliefs of all baseless assumptions through the careful examination and evaluation of the available evidence. And I have respect for anyone who furthers the causes of reevaluation and self-examination with regards to the evidence for each belief held by themselves and others.

One person who has caused some stir and some indignation among internet logicians on the topics of overcoming biases and culling faulty beliefs is A.I. researcher and Harry Potter fanfiction author Eliezer Yudkowsky. For me, it is occasionally frustrating to read Yudkowsky’s articles; he oscillates between, on the one hand, being a careful thinker who restricts his assumptions and tries to appropriately match evidence to confidence and, on the other hand, fancying himself a strange guru figure and espousing a religious fervor for Bayesian rationality.

Thomas Bayes (allegedly) - René Descartes - beliefs, minimizing assumptionsIn the end, though, there are some of his articles, like this one on scientists who hold supernatural beliefs, which are lucid distillations of the hypocrisy involved in some forms of belief and some claims of knowledge—and the hypocrisy involved in restrictions on the scope of evidence as a concept. (And for good examples of the same writer at his least helpful, just follow either of the links in the ‘addendum’ at the bottom of that article.)

The essential kernel of that linked article can be found in this wonderful sentence near the middle of it, which perfectly expresses what I mean by ‘the scope of evidence:’ “Maybe our spiritual scientist says:  ‘But it’s not a matter for experiment.  The spirits spoke to me in my heart.’  Well, if we really suppose that spirits are speaking in any fashion whatsoever, that is a causal interaction and it counts as an observation” (Yudkowsky).

It’s this kind of work on evidence being broadly construed as any proposed justification that should be the focus of any conversation about the state of modern belief. This is a demand for clarity and rationality as much as it is a call for minimizing assumptions. So, much as I would prefer if he would temper his claims—or at least ally them with sincere consideration of culture, art, and epistemologies that are alien to his own—Yudkowsky’s perspective may have some value if taken with a large grain of salt.


In conclusion, I take this Kantian solution to radical skepticism to be the phenomenological course of action; I take it to be the existential course of action; and even though he disliked Kant’s work, I even take it to be the Nietzschean course of action (insofar as Nietzsche’s considerations of wills, desires, and instincts relate to later existential and phenomenological positions). Now, do I take it to be the Cartesian course of action? Well, yes; even if his work is uneven at times with regards to assumptions, René Descartes’ contributions to the methods and applications of skepticism are nothing short of monumental.

Radical skepticism (construed as skepticism about the world as it is in itself) is irrelevant to my life, as I now live within (and shall only ever live within) the world as it appears to me. Indeed, I privilege the epistemological positions that I have outlined here because this is the only path I have found that meets this challenge to my personal satisfaction. Regardless, all epistemological competitors I have so far met require many more assumptions to get close to the same pragmatic position. And whatever the chances of this position falling to pieces later, I hope in the short-term to build a solid structure upon it—one that outlasts many nests.

Works Cited:

Descartes, René. “Meditations on First Philosophy in which the Existence of God and the Distinction of the Soul from the Body are Demonstrated.” Translated by Donald A. Cress. Classics of Western Philosophy 3rd Ed, pgs. 405-445. Edited by Steven M. Cahn. Hackett, 1990. Print.

Yudkowsky, Eliezer. “Outside the Laboratory.” LessWrong. 2007. Web.

[Topics: Assumption, Evidence, Skepticism, Belief]
The Least Assumptions:

Cartesian Skepticism, and Reducing Guesses and Assertions in a Belief Network to the Minimum

was last modified: December 8th, 2023 by Daniel Podgorski
Bookmark the permalink.

Comments are closed