Last modified on September 16, 2016, at 22:40

Your theory does not work under my theory, so your theory must be wrong

Your theory does not work under my theory, so your theory must be wrong is a special case of circular reasoning in which a protagonist tries to disprove a point of view by interpreting the facts through a different view. It is thus similar to the no true Scotsman fallacy. The logical structure of such an argument is:

  1. Fact A is interpreted by theory T as a.
  2. Interpretation a conflicts with theory U.
  3. Therefore, U is assumed to be wrong.


  1. A is interpreted by theory U as b.
  2. Interpretation b is consistent with view U.

In such a case, the holder of Theory U could as easily use that argument against the holder of Theory T—and the proponent of Theory T would have no just cause to challenge that argument. (To do so would constitute special pleading.)

In challenging a theory, one must not confuse the interpretation of a fact with the fact itself. Different theories infer different things from the same facts. Rejecting a theory out-of-hand merely because it infers things that your theory would not infer is not logical and is not good science. The proper way to challenge an opposing theory is:

  1. To attempt to show that the theory is not self-consistent—i.e., that it leads to contradictions, or failing that,
  2. To show that the opposing theory infers a given proposition, and then to show definitively that that proposition is contrary to fact. For example, the phlogiston theory of fire held that a flammable substance always contained another substance, called "phlogiston," that actually burned. Antoine Lavoisier demonstrated a combustion reaction in which the solid products clearly weighed more than the initial fuel, a thing that the phlogiston theory could not possibly explain.


See also