Recent Work on Epistemic Possibility and the Burden of Proof

It’s been a while since I’ve posted on epistemology. Because I recently came across a paper that touches on a current project of mine in epistemology—one that is also inspired by an idea from Rand—I thought now was a good opportunity to post again about this field.

First, the connection to Rand. In the following passage from Atlas Shrugged, Eddie Willers, assistant to Dagny Taggart, breaks the news that a government scientific agency has issued a warning about the safety of a metal that Dagny is using to build an important railroad line:

“They . . . You’d have to read it.” He pointed to the newspaper he had left on her desk. “They haven’t said that Rearden Metal is bad. They haven’t said that it’s unsafe. What they’ve done is . . .” His hands spread and dropped in a gesture of futility.

She saw at a glance what they had done. She saw the sentences: “It may be possible that after a period of heavy usage, a sudden fissure may appear, though the length of this period cannot be predicted. . . . The possibility of a molecular reaction, at present unknown, cannot be entirely discounted. . . . Although the tensile strength of the metal is obviously demonstrable, certain questions in regard to its behavior under unusual stress are not to be ruled out. . . . Although there is no evidence to support the contention that the use of the metal should be prohibited, a further study of its properties would be of value.”

“We can’t fight it. It can’t be answered,” Eddie was saying slowly. “We can’t demand a retraction. We can’t show them our tests or prove anything. They’ve said nothing. They haven’t said a thing that could be refuted and embarrass them professionally. It’s the job of a coward. You’d expect it from some con-man or blackmailer. But, Dagny! It’s the State Science Institute!” (pg. 174)

This is one of the first indications in Rand’s work of what would later become a distinctively Objectivist approach to a standard issue in logic, the burden of proof. Who has the burden of proof in a dispute? The person making the claim, or the person who would challenge it? The traditional answer in logic texts is that it is the one making the claim, and Rand agreed. But she added two important clarifications.

First, it is evidence that gives claims their cognitive content, such that without it, there is no claim to be assessed: such “arbitrary” claims are neither true nor false. Second, as a consequence, the burden of proof applies not only to claims asserted with certainty (e.g. “X is true”) but also to claims with weaker assertive force (e.g., “possibly X is true”). This is precisely the problem with the statement from the State Science Institute. Because it speaks of “possibilities” not supported by evidence, it hasn’t said anything that can be confirmed or refuted.

Arbitrary “maybes” of this sort are tools not only of the skeptics in epistemology but also of conspiracy theorists. So Rand’s view denying the cognitive status of such claims is an important part of her critique of contemporary philosophical methodology, and an important addition to a healthy ethics of belief.

To my knowledge, Rand never wrote at length on this topic in her nonfiction philosophical work. But she did comment on “arbitrary hypotheses” (“What if?” propositions without evidence) in the the workshops conducted on Introduction to Objectivist Epistemology (see pg. 306 of the second edition appendix), calling the reliance on these hypotheses the “dead end of human epistemology,” and “a mind-destroyer.”

Rand’s students would later elaborate on the theory she passed down through oral tradition. An early statement of the theory is in Leonard Peikoff’s “Maybe You’re Wrong” (April 1981, The Objectivist Forum), but the locus classicus is Peikoff’s statement in Objectivism: The Philosophy of Ayn Rand (1991) describing the nature of arbitrary claims as neither true nor false and the contextual nature of certainty (pp. 163-181). Here’s a representative sample:

A conclusion is “possible” if there is some, but not much, evidence in favor of it, and nothing known that contradicts it. . . . There are countless gratuitous claims in regard to which one cannot cite any contradictory fact, because they are inherently detached from facts; this does not confer on such claims any cognitive status. For an idea to qualify as “possible,” there must be a certain amount of evidence that actually supports it. If there is no such evidence, the idea falls under a different concept: not “possible,” but “arbitrary.” (176)

I should also mention that very recently, Harry Binswanger has elaborated in detail on his understanding of the burden of proof in his recently published How We Know: Epistemology on an Objectivist Foundation (TOF Publications, 2014, pp. 279-292).

Now I’d like to briefly draw attention to surprising places where philosophers who likely did not know about Rand are starting to catch up with this distinctively Objectivist proposal.

Though they were some of the few to do it, Objectivists were not the only twentieth century philosophers to require evidence of possibility claims. In my research I’ve discovered that a number of mid-century ordinary language philosophers did as well. These include J.L. Austin in “Other Minds” and, more extensively, Norman Malcolm in his essay “The Verification Argument” (in Knowledge and Certainty, Cornell 1975). But few other philosophers seem to have paid attention to Austin and Malcolm on this point. One notable exception is the work of the late Jonathan Adler, whose book Belief’s Own Ethics (MIT Press, 2002) devotes an entire chapter to applying the burden of proof principle to “possibility.”

Very recently, philosophers working in both epistemology and semantics have come to realize that the question of what separates epistemic possibility from other types of modality deserves more attention. They recognize that it is not enough for a claim to be free of formal contradictions to count as epistemically possible; it must also bear a distinctive relationship to a body of knowledge. But they are vexed as to the nature of the relationship. Most who are party to the debate maintain that the relationship is merely negative: a claim is epistemically possible if it is not ruled out by what we know. The dispute is then over which body of knowledge and whose knowledge is to count. A representative sample of the current debate in semantics is to be found in Andy Egan and Brian Weatherson’s collection Epistemic Modality (Oxford, 2011).

Because I think many of the latest proposals fail to silence the skeptics and the conspiracy theorists, I was delighted to learn this past week of a forthcoming paper by Katrina Przyjemski in Topoi, “Strong Epistemic Possibility and Evidentiality.” While I don’t agree with everything in this paper, it is a major step forward in the debate. Notably, Przyjemski draws a parallel between the notion of epistemic possibility and moral/legal permissibility, noting that while the “orthodox” view of epistemic possibility is parallel to a recognized “weak” notion of permissibility (not being ruled out by a body of rules or law), there is no concept of epistemic possibility that is parallel to the recognized “strong” notion of permissibility (express support by the rules or law). Przyjemski goes on to point out that requiring positive evidential support solves various semantic puzzles.

In my own work, I have applied what I take to be a lesson of Ayn Rand’s theory of concepts, that concepts are not to be multiplied beyond necessity, to show why “strong” epistemic possibility is the only justifiable concept of epistemic possibility, whereas the “weak” version of the concept serves no legitimate cognitive purpose. My own paper on this issue, “A Positive Evidentialist Account of Epistemic Possibility” ( version here) offers the “positive evidentialist” theory as the simplest solution to many of the same semantic puzzles about epistemic possibility discussed by Przyjemski, but also tries to claim a number of other theoretical advantages.

At present, my work does not yet touch on the question of why evidence is necessary for the cognitive content of possibility claims. I hope that if my paper is published, I can use this as a springboard for further exploration of that topic. I am already convinced that fruitful parallels can be drawn between this issue and the demarcation problem in the philosophy of science.

I have presented my paper at three different workshops now, but it has been rejected by a number of journals. It’s hard to know, especially when the journal editors do not give feedback, if this is because the paper still has obvious flaws, or because it is too unorthodox for them to take seriously (or both). The paper is under review now at a new journal, but it will still probably need more work, so I do welcome your feedback in the comments section below.

Tragically, Przyjemski died before finishing her dissertation on this topic under Kit Fine at NYU; her paper was published posthumously. Since Jonathan Adler died before his time as well, I feel like I’ve now lost two important potential allies. Even still, it is heartening to see that philosophers are starting to see the problems with a key methodological assumption that has, arguably, stultified progress in their discipline for decades if not centuries. Rand was an early critic of this methodology, and it is also nice to see her critique at least modestly vindicated.

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