False Equivalence

Is an informal fallacy in which an equivalence is drawn between two subjects based on flawed or false reasoning. This fallacy is categorized as a fallacy of inconsistency. Colloquially, a false equivalence is often called "comparing apples and oranges."

Examples:

1. "The Deepwater Horizon oil spill is no more harmful than when your neighbor drips some oil on the ground when changing his car's oil."
   The "false equivalence" is the comparison between things differing by many orders of magnitude: Deepwater Horizon spilled 210 million US gal (790 million L) of oil; one's neighbor might spill perhaps 1 US pt (0.47 L).
2. "They are both Felidae, mammals in the order Carnivora, therefore there's little difference between having a pet cat and a pet jaguar."
   The "false equivalence" is in an oversimplification of the factors that make an animal a suitable pet.
3. "Consuming marijuana can lead to consuming and acquiring a psychological dependence on heroin later in life by acting as a gateway drug, so taking marijuana is like taking heroin."
   The "false equivalence" is not considering the difference in likelihood. Consuming heroin is more likely to lead to future heroin dependence than taking marijuana, even given the assumption that one who begins using marijuana is more likely at some later time to try heroin, than someone who has never used marijuana.