The key concept in deductive logic is the concept of validity. One good way to learn to understand the concept of validity better is to discover what makes arguments invalid.

PREPARE: by reading carefully the required portions of Chapters 3 and 4, paying special attention to the sections from Chapter 3 about validity and using the counterexample method. Take a look as well at the required resources from this week, especially those that discuss the concept of validity.

REFLECT: on one of the argument from the following list of arguments (avoid choosing the same argument as others in the class). Consider the way in which the reasoning is actually invalid (even if perhaps only subtly). Think about why that argument is invalid in the sense that it would be possible for all of the premises to be true and the conclusion false.

Choose from the following argument options:

Everyone has to eat food with adequate calories.

A bag of Doritos is food with adequate calories.

So everyone should eat a bag of Doritos.

All winos drink alcohol.

All alcoholics drink too much.

Therefore, all winos are alcoholics.

If I wear that cologne then women will love me.

I bought that cologne.

So women are going to love me.

The sun has risen every morning for millions of years.

The sun rises because the earth turns every 24 hours.

Therefore, the sun will rise again tomorrow morning.

WRITE: the argument that you have chosen in your post. Then, demonstrate that the argument is invalid in one of two ways: Either explain a scenario in which the premises could be true and the conclusion false, or find another argument with the same form that has true premises and a false conclusion. Once you have done so, examine if there is anything that could be done to make the argument valid. Make sure to include citations and references in APA form.

RESPOND TO FELLOW CLASSMATES: start by reading the reflections of your classmates and examine their analyses. Above all, seek posts that are problematic and not those that you find in good shape. If you believe that the examination is incorrect, then explain why (cite and reference the course material that informed you) and provide an example that demonstrates your point. In particular, explain a way in which it would be possible for the premises to be true and the conclusion false.