Appeal to authority
Insisting that a claim is true simply because a valid authority or expert on the issue said it was true, without any other supporting evidence offered.
Richard Dawkins, an evolutionary biologist and perhaps the foremost expert in the field, says that evolution is true. Therefore, it’s true.
When writers or speakers use appeal to authority, they are claiming that something must be true because it is believed by someone who said to be an “authority” on the subject. Whether the person is actually an authority or not, the logic is unsound. Instead of presenting actual evidence, the argument just relies on the credibility of the ‘authority’.
“A commercial claims that a specific brand of cereal is the best way to start the day because athlete Michael Jordan says that it is what he eats every day for breakfast”