What is fallibilism?

“Are you sure?” is a common response to someone who makes a questionable claim, expresses a dubious belief, or defends a problematic value. In philosophy, specifically in the branch called epistemology (i.e., the study of knowledge), this question reflects a deeper issue. In asking, “Are you sure?” the philosopher asks, “Can a person ever be certain about what he knows?” Fallibilism—from the word fallible, meaning “capable of making mistakes”—is the view that no one can ever be certain of his or her knowledge. Fallibilism argues that any belief, no matter how well-supported, could be mistaken. Thus, fallibilism claims that all human knowledge is open to revision and correction.

In philosophy, fallibilism is sometimes contrasted with certain forms of foundationalism. Foundationalism holds that a belief system can be built upon certain basic beliefs, called foundational beliefs. These are considered infallible because they are self-evident or beyond a reasonable doubt. For example, 2 + 2 = 4 is often treated as foundationally true and not open to correction.

In contrast, fallibilism asserts that even the most well-supported beliefs, including foundational ones, could be mistaken. Thus, no belief is ever beyond the possibility of error. Proponents of fallibilism acknowledge that it is extremely unlikely that 2 + 2 = 4 would ever be overturned. However, they maintain that, in principle, even such a basic sum isn’t absolutely certain because future discoveries may change humanity’s understanding of it.

Foundationalism, on the other hand, begins with certain basic truths that serve as the building blocks for a coherent belief system. This means that foundational truths can support additional beliefs that are supplemental, derived, or logically implied from them. Axioms lead to corollaries. For instance, if 2 + 2 = 4 is foundational, then, by inference, we can be certain that 4 − 2 = 2.

Fallibilism contends that, while the inference 4 − 2 = 2 is highly reliable, it isn’t infallible. Although no current knowledge challenges this equation, history shows that foundational truths have been wrong on occasion. Fallibilists often point to Galileo Galilei’s (and Nicolaus Copernicus’s) challenge to the earth-centered model of the solar system. When Galileo argued that the sun, not the earth, was at the center, he used new observations to overturn widely accepted beliefs.

According to fallibilism, a person can’t know with certainty whether a tree is actually a tree, or a car is actually a car. One might be dreaming, hallucinating, or experiencing a brain injury that distorts perception. Foundationalism replies that, while perceptual errors are possible, it’s nevertheless true that trees and cars exist as objective realities—and it is because they do that people can have notions of them in the first place.

The Bible teaches that human knowledge is limited. Unlike God, people are not all-knowing. Not only do they lack complete knowledge, but they can also believe things that are false, either because of misunderstanding or deception. Still, the fact that our knowledge is limited or sometimes mistaken does not prove fallibilism to be true. Just because people can be wrong doesn’t mean objective truth doesn’t exist or that accurately knowing that truth is impossible.

The Bible affirms that God has revealed absolute truth. In John 17:17, Jesus prays to the Father, saying, “Your word is truth.” Likewise, Psalm 119:160 declares, “All your words are true; all your righteous laws are eternal.” If Scripture is infallible, as Jesus and the psalmist declare, then fallibilism cannot be true. No future revelation from any source can alter or replace the truth of Scripture or the fact that Jesus is the ultimate manifestation of truth (John 14:6).

In contrast to fallibilism, the Bible presents a view of truth that is not subject to revision. Truth can be known, and it is founded upon the unchanging character of God and fully revealed in Jesus Christ.