False appeals in argumentation and rhetoric

Appeal to Authority
In one advertisement for a skincare product, the company claimed “most dermatologists recommend...” the product. This is an appeal to authority: a classic logical fallacy. With an appeal to authority like this one, the speaker bases its claim solely on the authority of an individual or institution. In this case, the company uses dermatologists as their symbol of authority on skincare. While dermatologists are experts in the medical treatment of skin, a product still needs to be tested empirically.
Appeal to Pity
This false appeal is also used widely in advertisements, particularly those that promote charitable organizations. One commercial shows malnourished children, and begs for the viewer’s money, claiming that the money can help these poor children. Appealing to pity is a variant on emotional appeals more broadly, in which the speaker manipulates audience sentiments, which can cloud rational judgment.
Appeal to Fear
Fear-based appeals are used constantly, particularly by politicians. For example, a mayoral candidate claimed that they were going to institute several “tough on crime” measures to make the city safer. Yet one reporter showed that crime rates had actually been going down the past several years, and that these “tough on crime” policies would do more harm than good. The candidate still won the election, though, based on n appeal to the public’s fear that their neighbors are dangerous.
Appeal to Ignorance
An interesting appeal to ignorance comes from those who believe that the moon landing was faked. In a conversation, one person said that there is “no proof” that the moon landing occurred, because the photographs and video could have been altered. This is a classic appeal to ignorance: claiming that just because they cannot provide some acceptable evidence that the moon landing was fake.
Appeal to Personal Attack
Also known as ad hominem, the appeal to personal attack is very common in arguments and debates. One example is when people say that Donald Trump is an idiot, rather than focusing on the substantive content of what the President says or does.