Substituting explanation for premise

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Not to be confused with Fallacy fallacy, where (possibly) factually incorrect yet logically fallacious explanation is used to discredit the argument it supports.

Substituting explanation for premise is a logical fallacy that occurs when a flawed explanation for a phenomenon is taken as evidence that the phenomenon did/does not occur at all.

The fallacy is a formal fallacy.

Alternate names[edit]

  • Theoretic fallacy


P1: Explanation X explains the occurrence of event Y.
P2: Explanation X is wrong.
C: Event Y did/does not occur.

The fallacy ultimately follows the fallacious form:

P: Not X.
C: Not Y.


When this fallacy is committed, someone may attempt to refute claims that the phenomenon occurs by refuting the theory invoked to explain it. It is fallacious because the reason for believing the phenomenon in question to occur is independent of the theory used to explain it.

This fallacy probably results from a failure to distinguish the reasons for a phenomenon from the reasons to believe a phenomenon occurs. For example, the theory of evolution by means of mutation and natural selection can be used to explain the presence of transitional fossils and the high levels of consistency of phylogenetic trees created with different methods. If one determined that the theory did not suffice to explain these phenomena, it would not follow that the phenomena are not real.


The point(s) where the fallacy is committed is/are italicized.

  1. Alice proposes that iguanas are green because their skin contains chlorophyll. Bob points out that animals do not produce chlorophyll. He claims that therefore, iguanas must not really be green.
  2. Bob suggests that meteors burn up upon entering Earth's atmosphere because they are heated up by the friction from passing air molecules. Alice points out that this effect is not significant enough to generate the heat necessary to burn the meteors, and claims that therefore meteors really do not burn up upon entering the atmosphere.


You do not commit this fallacy if you:

  • Make the inverse of this claim. A theory can be refuted if a predicted phenomenon does not occur.
  • Assert that a claim is false because it is poorly supported. This is the fallacy fallacy.

See also[edit]