What is Agrippa's trilemma?

Agrippa’s trilemma is a philosophical argument about the challenge of justifying truth claims. It’s named for a first-century Greek philosopher known as Agrippa the Skeptic, not to be confused with Herod Agrippa I or Herod Agrippa II in the New Testament. The word “trilemma” refers to three problems that arise when a person attempts to prove that a statement is true. When measured against the teachings of Scripture, it’s clear that Agrippa’s trilemma does not reflect a biblical worldview of knowledge or truth.

Agrippa’s trilemma is commonly encountered in epistemology, the branch of philosophy that studies knowledge. In summary, it argues that any attempt to justify a truth claim relies on unproven assumptions. Even a basic statement like “ice is cold” relies on assumptions about the definitions of words and ideas.

Beyond claims based on experience, some philosophers extend the argument to logic and math. For instance, the assertion that 4 is the sum of 2 + 2 depends on formal definitions—such as what “2” means—that are assumed rather than proven. According to the trilemma, assigning meaning to the number “2” is based on assumptions rather than proven facts. Proving the definition of “2”—not to mention “4,” “sum,” and “+”—is needed to say the assertion is true.

According to the argument, three problems arise when someone tries to prove a truth claim. First, a person attempting to make such an assertion must keep supporting each claim with another one indefinitely, never arriving at a final justification. After asserting “ice is cold,” a person attempts to clarify the meaning of each term, for example, by defining ice as frozen water. To then show that their new assertion is correct, they must give a reason for their understanding of the words frozen and water. From here, the regression continues forever. Some refer to this scenario as an infinite chain of proofs.

The second possible outcome is that the person ends up where they started, which is called circular reasoning or begging the question. This is when the conclusion of an argument is assumed in its premise. For instance, saying that the ice is cold because all ice is cold is circular reasoning. In the field of logic, circular reasoning is a fallacy.

The third possibility is that a person accepts certain claims without further support, treating them as foundational or self-evident. While this avoids infinite regress and circularity, it raises the question of whether such starting points are justified.

Biblically, Agrippa’s trilemma does not account for the reliability of the Bible’s truth claims. Truth is an attribute of God and a defining characteristic of Scripture, since He is “the God of truth” (Isaiah 65:16) and His Word is truth, as Jesus prayed, “Sanctify them by the truth; your word is truth” (John 17:17). In Scripture, the justification of truth is not primarily about whether it can be proven from a human perspective, but about what God has revealed as truth.

Like many other “empty philosophies” (Colossians 2:8, NLT), which question whether beliefs can be fully justified, the Agrippa trilemma collapses under its own logic. If it is true, then the argument itself cannot be fully justified. It, too, would face one of the three problems it describes. In this way, the argument circles back on itself, returning to where it started without advancing understanding or reasoning.

Biblically, discovering truth starts with knowing Jesus Christ, who said, “I am the way and the truth and the life. No one comes to the Father except through me” (John 14:6).