Appeal to Probability Fallacy – Definition and Examples

Appeal to Probability Fallacy - Definition and Examples - Fallacy in Logic

Appeal to probability is a logical fallacy, or an error in reasoning, in which someone states that since something is probable, it is certainly so.

It belongs to the category of informal fallacies. Furthermore, its different variations include the appeal to improbability and the appeal to possibility.


Appeal to probability occurs when someone argues that because something will probably happen, or is probably true, it will necessarily happen, or is necessarily true.

The logical form of the argument is:

  • X is probable.
  • Therefore, X is certain.

In other words, one mistakenly assumes that they can take for granted something that is probably the case. This is clearly fallacious: a probability is not the same as certainty, and, in terms of logic and argumentation, shouldn’t be treated as such.


  • “If I keep doing this long enough, I will probably succeed; therefore, I will succeed.”
  • “Considering that everything around us has some kind of a cause or creator, it is probably true that the universe has a creator too. Therefore, the universe must have a creator.”
  • “I would say that our chances to win the game tonight are more than 50%. We have nothing to worry about!”
  • “Earth is just one planet among billions of others. It cannot be the only planet with intelligent life on it.”
  • “The real estate market has been in an uptrend for a long time; therefore, it will keep going up this year too.”


Appeal to improbability is the inverse form of the previously explained fallacy. It’s based on the assumption that if something is improbable, it must be impossible.

  • X is improbable.
  • Therefore, X is impossible.

Appeal to possibility is almost identical to the appeal to probability, but its typically seen as a specific variation of the latter. It argues that since it’s possible for something to be true, it must be true.

Thus, its logical form is:

  • X is possible.
  • Therefore, X is certain.

An example would be:

  • “It is completely possible to pass the exam without studying. So, I will pass the exam without doing any studying.”

Similarly, this is fallacious because a possibility does not correlate with certainty, nor is it the same as probability.