Exam 7: A Little Categorical Logic, Analyzing Arguments, Evaluating Arguments and Truth Claims

Consider this statement: "Doctor Who is the greatest sci-fi series of all time." What would be the best way to rephrase this statement to use it in a Venn diagram?

In argument diagramming, an arrow means "supports" or "is evidence for."

In evaluating the sufficiency of an argument's supporting premises, it is important to ask:

An argument can be refuted by showing:

All syllogisms have two premises.

From a critical thinking standpoint, an argument can be a good argument even if it lacks literary or rhetorical merit.

A common stylistic variant of the statement "No Democrats are Republicans" is

Refuting an argument by citing an example that shows that a key general claim of the argument is false is known as:

In the following argument, there are ______ premises (including subconclusions) that should be diagrammed: "If souls die, they must die either by decomposing or by annihilation. But what is not composed cannot decompose. And souls are not composed. Therefore souls cannot decompose. And nothing is annihilated as a whole. Therefore souls are not annihilated as a whole. Thus souls do not die either by decomposition or annihilation. Thus souls do not die. (Peter Kreeft and Ronald K. Tacelli, Handbook of Christian Apologetics)

A good inductive argument must be logically valid.

A categorical statement is a statement that asserts positively and without qualification that a certain person, place, or thing exists.

In argument diagramming, premises should always be placed above the conclusions(s) they are claimed to support.

In the following argument, there are ______ premises (including subconclusions) that should be diagrammed: "Either you will eat an apple at lunch tomorrow, or you will not. If you will eat an apple at lunch tomorrow, then nothing you do between now and then will stop you from having that apple at lunch. If you will not eat an apple at lunch tomorrow, then any effort you make between now and then to eat such an apple will be, literally, fruitless. Therefore, you do not have two equally available options to eat or not to eat the apple. Thus, you are not really free concerning whether you will or will not eat an apple at lunch time tomorrow. (Tom Morris, Philosophy for Dummies, 1999 [slightly adapted])

In evaluating an argument, we should ask:

From a critical thinking standpoint, a good argument should be

In general, if an unsupported claim fits well with our well-supported background beliefs, it is reasonable to accept it.

All standard-form categorical statements include one of the following quantifiers:

In modern logic, the statement "Some dogs are mammals" can be validly inferred from the statement "All dogs are mammals."

One of the watchwords of critical thinkers is to never believe more strongly than the evidence warrants.

To refute an argument is to challenge or criticize it.