First Lady Melania Trump with Special Guests |
The problem, however, comes when we use examples that are insufficient. Although examples, personal stories, and comparisons are wonderfully persuasive, they are not always logically valid. To give valid proof, examples need to meet these familiar tests:
1. There must be more than one example. One example proves nothing. Suppose one of my university students had dated a man, and he turned out to be a jerk. What a shame. Would that prove that all men are jerks? Or even that most men are jerks? No, it would not. It would only prove that one man was a jerk.
Mr. Trump's speech basically gave one example--one special guest--for each of his points. He gave one example of a welder who was using his tax cut, which he had not yet received, to buy a new house. That wasn't enough to establish a trend. An exception is that he introduced the parents of not one, but two, girls who were cruelly murdered by MS-13 gang members. That was, at least, two examples of a horrible crime. Even so, was this enough to establish that immigrants were, in general, threats to public safety? That is debatable. Even two examples, however powerful (and these were emotionally powerful examples), represent minimal evidence.
2. Also, the examples must be typical. MS-13 members are not typical immigrants, and so these two tragedies, although horrible, didn't prove that immigrants are dangerous in general. (Still, a Trump supporter could argue that if we excluded all immigrants, we would have excluded the MS-13 members. That seems draconian, but valid.) That one American feels optimistic about the tax cut is evidence of the tax cut's worth, but does not, by itself, prove that consumer confidence is rising over the entire nation. We would need more examples, and probably an economic analysis, before we could say that the speaker has proven his point.
3. The speaker should account for counter-examples. For instance, Mr. Trump should account for immigrants who came to the United States, set up a business, and contributed to the community. There are many such people--I would be happy to supply some names--and they could equally have been invited to sit next to the First Lady and to receive presidential recognition. Of course, the First Lady is herself an immigrant, and yet the President did not call out her status as an immigrant who has made a massively positive contribution. However, since such counter-examples would not support the President's strict immigration policies, President Trump did not recognize such cases, and therefore his proof had a big gap.
So, examples are very convincing and can give evidence for the speaker's point but do not always prove the speaker's point. The personal stories that President Trump told about his wife's special guests were important, but insufficient to prove that his policies had merit.
Of course, at some point the listeners should apply these critical tests to determine whether the speaker had proven his point. The President is an advocate, but the audience must listen, not with cynicism, but with care, so they will only believe things for which there is enough evidence.
Photo from White House Flikr page