For your first online activity, we'll be exploring the nature of arguments. Please watch the following videos on the concepts of validity and soundness - two important properties of arguments:...

For your first online activity, we'll be exploring the nature of arguments. Please watch the following videos on the concepts of validity and soundness - two important properties of arguments:

https://www.youtube.com/watch?v=kdJ6aGToDlo

https://www.youtube.com/watch?v=3P0fUHUaZcs

Then please review the handout on valid and sound arguments. (Click on the “Handouts” link – it’s currently the only, handout there).

When you’ve reviewed all of these materials, please complete the following exercises:

• Write up an argument that is valid, but not sound.


• Write up an argument that is valid and sound.

Each argument should be in the following form:

1. …….. (Premise)


2. …….. (Premise)


3. Therefore …….. (Conclusion)

Microsoft Word - Arguments Handout Valid, Sound and Probabilistic Arguments Fall 2019 Arguments An ARGUMENT is a set of statements (also called premises) offered in support of a conclusion. For example 1. The Dolphins have a good quarterback. (Premise) 2. Teams with good quarterbacks get high TV ratings. (Premise) 3. Therefore the Dolphins will get high TV ratings. (Conclusion) A VALID argument (sometimes referred to as a DEDUCTIVE argument), is an argument where, IF the premises are true, the conclusion MUST be true. The example above is valid. Another example of a valid argument is: 1. Socrates is a man. (Premise) 2. All men are purple turtles. (Premise) 3. Therefore Socrates is a purple turtle. (Conclusion) Notice that the second premise is false. Nevertheless, the argument is valid. That’s because it’s still the case that IF the premises are true, the conclusion MUST be true. Put another way, it is IMPOSSIBLE for the premises to be true, and the conclusion to be false A SOUND argument is an argument that is VALID and in which all of the premises are true. For example: 1. Socrates is a man. (Premise) 2. All men are mortal. (Premise) 3. Therefore Socrates is mortal. (Conclusion) Notice that the argument meets both requirements for being sound. First, it’s valid, since if the premises are true, the conclusion must be true. Second, the premises are true. Notice also that in a sound argument the conclusion itself must be true. Why?  Well, first the argument must be valid, meaning that IF the premises are true, the conclusion must be true.  Second, for an argument to be sound, the premises must indeed be true.  Thus, the conclusion must be true as well.