Suggesting that because two things are alike in some way and one of those things is like something else, then both things must be like that “something else.” In essence, the ad Hitlerum fallacy is an extended analogy because it is the attempt to associate someone with Hitler’s psychotic behavior by way of a usually much more benign connection.
Examples:
- Jennie: Anyone who doesn’t have a problem with slaughtering animals for food, should not, in principle, have a problem with an advanced alien race slaughtering us for food. Carl: Fruitarians, the crazy people who won’t eat anything except for fruit that fell from the tree, are also against slaughtering animals for food. Are you crazy like them?