Counter-premise vs Weakening statements vs Alternate Viewpoints

[tifftillinghast]

I was completing the "Premise and Conclusion Analysis Drill" in the additional reading for lesson one (pg 1-16) number 1. I marked "Although Davis usually teaches class on Thursday" as a premise, however, it is stated in the answer that it is not a premise because it weakens the argument. I am having a difficult time digesting the difference between a counter-premise, which seemingly counters the argument (which feels like weakening aka "weakening statement") and a weakening statement. Can someone please break down what the difference is and use an example or two that will make it more clear? Also, alternate viewpoints feel as though they are a gray area that can weaken the argument which make it a "weakening statement"?

[Chandler H]

Hi Tiff,

Good question. Let's start with a very simple argumentative setup:

The temperature will probably be under 32º F tomorrow. The weatherman says it will probably snow tomorrow, and the temperature has to be under 32º F for it to snow.

The two premises (Must be under 32º to snow/Weatherman says it will probably snow tomorrow) lead us to the conclusion (It will probably be under 32º tomorrow). This is a pretty self-explanatory argument!

Now let's see what happens if we add a counter-premise:

The temperature will probably be under 32º F tomorrow. Although it's been warm all week, the weatherman says it will probably snow tomorrow, and the temperature has to be under 32º F for it to snow.

"It's been warm all week" is a statement which raises an issue with the conclusion ("The temperature will probably be under 32º tomorrow"). However, the "Although" indicator tells us that the statement is about to be addressed by the following clause, which it is. A counter-premise is a statement that is raised as part of the argument, but is subsequently addressed in a direct manner. Therefore, a counter-premise ultimately strengthens the argument by addressing a potential issue that could weaken it.

On the other hand, a weakening statement is not part of the argument, but a response to the argument. A weakening statement in response to our argument above might look like this:

Andy: The temperature will probably be under 32º F tomorrow. The weatherman says it will probably snow tomorrow, and the temperature has to be under 32º F for it to snow.

Bob: But the weatherman is often wrong when he predicts snow.

Bob's response is a statement which weakens the initial argument by directly attacking one of the premises ("The weatherman says it will probably snow tomorrow"). Therefore, this is a weakening statement.

Finally, let's talk about alternate viewpoints. You can think of an alternate viewpoint as a device used to deliver a counter-premise. It simply provides a reason to bring up that counter-premise. The use of an alternate viewpoint in our example might look like this:

Some people claim that it will probably be warm tomorrow, because it's been warm all week. However, the temperature will probably be under 32º F tomorrow. The weatherman says it will probably snow tomorrow, and the temperature has to be under 32º F for it to snow.

Do you see how the alternate viewpoint ("some people claim") is simply a delivery device for the counter-premise ("it's been warm all week")? Ultimately, the argument is not weakened, despite the inclusion of this alternate viewpoint—that's why it's not a weakening statement.

Now, let's bring it back to the drill in Lesson One. Our conclusion is that "Professor Davis will probably not teach class on Thursday." The statement that "Davis usually teaches class on Thursdays" is a counter-premise because, although it raises an issue with the argument, that issue is resolved by the two statements that follow (that he rarely teaches more than one class in a week, and he already taught one class this week). Again, ultimately, the argument is not weakened by the inclusion of the counter-premise.

Does this all make sense?