Friday, September 10

Valid vs Strong Arguments

Years ago I met some friends that moved from Colorado to California. As young children they believed that they were moving to a city by the ocean, because most TV shows at the time had depicted California cities near the beach. They were sad to learn that San Jose was not located directly on the beach.

Here is a strong argument they might have heard to convince them:
California is a state bordered by an ocean. San Jose is a city in California. San Jose is a city located near the ocean.

While the above argument can be considered strong, because both premises are true, the conclusion can be considered somewhat false (especially to my friends who were looking forward to walking to the beach and not driving 1 hour). It this case the argument intended audience (my friends) would have been open to open to the possibility that San Jose was closer to the ocean, while most Californians would suspect otherwise.

A stronger argument would be:
California is one of 5 U.S. States that is bordered by the Pacific Ocean. Santa Cruz is a coastal city in California. Santa Cruz is bordered by the Pacific Ocean.

This argument is valid because it contains both true premises and a true conclusion that follows the premises. The information is both true and valid, because it follows a specific line of reasoning and fact. (Oh, by the way, my friends now live in Santa Cruz).

1 comment:

  1. I really liked your example of strong versus valid arguments. It was a really clear argument, and you seemed to write the post in a way that showed you really understood the topic. I like how you first wrote a possible strong argument for your friends that previously lived in San Jose and then wrote another even stronger argument on the same topic. It just goes to show that although an argument may seem strong, sometimes there’s another argument on the same topic that is a lot stronger than the previous one, it just takes a little switching around or perhaps some more brain power on the subject to figure it out.

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