Basic Concepts
A true or false statement that precedes the conclusion
Premise
Hypothetical Syllogism
Adam Smith stated that markets are guided by an invisible hand. Adam Smith is the father of economics. Therefore, markets are guided by an invisible hand.
Argument from Authority
Appeal to Ignorance
Every woman has the right to do what she wants with her own body (as long as she harms no one else). Having an abortion is doing something with one's own body (and not harming anyone else). So, every woman has a right to have an abortion.
Begging the question
The part of logic concerned with tests for strength and weakness.
Inductive logic
Either virtue is good for its own sake or it is good as a means to an end. It is not the case that virtue is good for its own sake. So, virtue is good as a means to an end.
Disjunctive Syllogism
80% of the class will fail the logic test tomorrow. You are in this class. You will fail the test tomorrow.
Statistical Syllogism
Why do all philosophical problems turn out, in the final analysis, just to be a question of how to define terms?
Complex Question
Your honor, my client is a first time mother with no father in the picture. Its hard to be in her position, so you should give her a second chance.
Appeal to pity
True or False: Weak arguments can cogent or uncogent
False, All weak argument are uncogent
What is the name of the famous flaw commonly found in invalid attempts at Modus Tollens
Denying the Antecedent
Thirty percent of the dogs that have been dissected have had kidneys. Hence, thirty percent of the members of the class of dogs have kidneys.
You are allowed to think whatever you want about this merger, but if you speak out against it, then you will be fired.
Appeal to Force
When you get down to it, philosophers are just lazy logic choppers who sit around trying to put reality into little boxes made of words. So, the philosophical arguments against time travel prove nothing.
Abusive ad hominem
True or false: It is impossible for the conclusion to be false if the premises are true in a strong argument.
False, "strong" refers to inductive forms which never guarantee the validity of the conclusion
Overeating is foolish only if it causes disease. Overeating does not cause disease. So, overeating is not foolish.
Modus Tollens
Nero, you'll recall, played his violin while Rome burned. Similarly, scholars play with ideas while civilization is threatened by the 'flames' of greed, poverty, racism, and violence. Now, plainly, Nero was morally irresponsible. Hence scholars are morally irresponsible also.
Argument from Analogy
Nuclear weapons are more destructive than conventional weapons. Therefore, over the course of human history, more destruction has resulted from nuclear weapons than from conventional weapons.
Composition
I read in the Seattle Times that most traffic accidents occur within five miles of your home. Now, given this fact, I'm forced to conclude that it would be a good idea for you to relocate to someplace more than five miles distant from your home.
Equivocation
True or False: Every valid argument with a false conclusion has at least one false premise.
True! Valid arguments guarantee the conclusion if the premises are true.
If Mary is a psychiatrist, then she is a physician. Mary is not a physician. Therefore, Mary is a psychiatrist.
None
Daily double!
True or false: Some arguments have more validity than other valid arguments
False, validity is an all-or-nothing category with no scale
The leader of this new religious group preaches the following message, "We shall wear no clothes to distinguish ourselves from our Christian brethren." Therefore, this religious group should be opposed. For it advocates nudity.
Amphiboly
Most Americans insist that terrorism is always wrong, but they are mistaken. Terrorism, after all, is simply the use of violence to further political ends. And no country on the face of the earth employs more violence to further its political ends than America does. So, Americans are in no position to condemn terrorism. Besides, one person's terrorist is another's freedom fighter. Why can't Americans see that their own revolutionary war heroes were all terrorists?
Complex question or tu quoque