What makes an argument a good argument? Philosophers have attempted to answer this question for thousands of years. We'll look at one standard for argumentation: deductive reasoning. After defining 'valid' and 'sound', we'll create some examples of valid, invalid, sound, and unsound arguments. Next, we will take a look at St. Anselm and St. Aquinas, Christian priests trying to prove the existence of God. For each of these mens' arguments, we'll determine what we think its problems are.

Rational discourse goes back thousands of years, but what is it that makes an argument good? We examine valid arguments and sound arguments, two terms that can help us determine whether arguments are good. This is done with two main examples: proofs of God's existence by St. Anselm (the Ontological Proof) and St. Thomas Aquinas (the Unmoved Mover Proof); in each we attempt to see if and where the arguments are problematic.

"An argument is a set of statements where one follows from the others: an argument is valid if whenever the premises are true the conclusion is also true: an argument is sound if it is valid and the premises are true..."

I gave the talk at the Akita Communicative English Studies group meeting. See http://www.edinet.ne.jp/~takeshis/images/AES06/AESadd7.html for more information.