LOGIC: How to Evaluate a Logical Argument

We very rarely encounter formally stated logical arguments but very frequently encounter arguments being made calling themselves logical arguments. How is a person to evaluate the claim being made? In my major, philosophy, this is something that we focus on a lot. Following the rule of charity we should reconstruct someone's argument by putting it in general form. The rule of charity is that you should always try as best you can to reconstruct someone's argument before evaluating it.

All logical arguments are either deductive or inductive. Deductive logic is the easiest and most intuitive for people to understand. I believe that part of what it means to be human is to think rationally. I also believe that God built the ability to see logical truths into the human mind. Inductive logic has not been formalized and does not give us the precision accuracy that deductive logic does. Here is one of the easiest general forms for a 2 premise deductive logical argument

P1. If X then Y
P2. X
___________
C. Y

P stands for premise and they are numbered in sequential order. C stands for conclusion.

This is most basic type of deductive logical argument in general form. By adding premises and sub conclusions they get increasingly complicated.

When evaluating a logical argument you cannot dismiss the conclusion because you don't like it or it doesn't fit into the framework of your preconceived notions. It is the truth of the premises that give the conclusion its justification. So if you want to evaluate an argument you analyze the premises NOT the conclusion. If you can falsify one of the premises, which occurs when you show a counter example to the premise, then you can logically reject the conclusion. If any one of the premises can be shown to be false then the conclusion must be rejected because it relies on the truth of all of the premises for it to be justified as true.

This is very entry level understanding of deductive logic and I would encourage everyone to take a logic course to understand it better. For those of you at Clarion, enroll in Dr. Phillips Logic 1 class, he teaches at least 1 section every semester.