Exam 10: Deduction and Induction: A Closer Look

Think with Socrates does not contain a section on enthymemes. However, the concept can be defined briefly. This exercise defines an enthymeme and gives students a chance to practice filling in holes in incomplete deductive arguments. An enthymeme is an argument that is missing one or more premises or a conclusion. Each of the following deductive arguments is missing either a premise or a conclusion. (Thus, each is an enthymeme.) Add a statement to each so as to turn the enthymeme into a valid argument. -If it rains, then the roof gets wet. Therefore, the roof is wet.

The following is one of the two ways to effectively criticize an argument:

The following is a strong argument: It has been snowing for sixty days straight, and the prediction is for the snow to continue tomorrow. Thus, tomorrow it will probably not snow.

If an inductive argument has all false premises, then you know it is weak.

The following is a strong argument: It has been snowing for thirty days straight, and the prediction is for the snow to continue tomorrow. Thus, tomorrow it will probably snow.

More enthymemes. In each case, fill in the missing element (i.e., add a premise or conclusion) so as to turn the enthymeme into a valid deductive argument. -All frogs are orange. No orange things are cute. So ...

On deductive arguments. -If an argument is sound, then it must also be valid.

The combination you will not find in a sound argument is:

Think with Socrates does not contain a section on enthymemes. However, the concept can be defined briefly. This exercise defines an enthymeme and gives students a chance to practice filling in holes in incomplete deductive arguments. An enthymeme is an argument that is missing one or more premises or a conclusion. Each of the following deductive arguments is missing either a premise or a conclusion. (Thus, each is an enthymeme.) Add a statement to each so as to turn the enthymeme into a valid argument. -No dingbats are serious. All the members of the serious people club are serious. Therefore, …

On deductive arguments. -If an argument has premises that are certain to be true and a conclusion that is certain to be true, then the argument must be valid.

The following is a weak argument: Joe has eaten lunch at the taco stand every day for sixty days straight. Thus, tomorrow he will probably not eat there again.

According to the text, logicians sort arguments into two types of reasoning: deductive and inductive.

For each set of values, determine the mean, median, and mode. -Eleven widgets were tested at the Ace Widget factory, and the following values were recorded: 11, 14, 12, 13, 14, 14, 18, 14, 16, 14, 15, , Determine the mean, median, and mode for this sample set of widgets. otal: 155. Mean: 14.09. Median:14. Mode: 14

Is the argument deductive (D) or inductive (I)? -It rained yesterday and the day before. Therefore, it probably will rain today.

The following is a valid argument: Ann is a chemist. All chemists are good at math. Therefore, Ann is good at math.

Inductive arguments are intended to show that the conclusion is probably true but not certain.

On deductive arguments. -If an argument is invalid, then it must have at least one false premise.

The following argument is valid: All students are billionaires. No billionaires are Republicans. So no students are Republicans.

If an argument is inductively strong, then it must also be cogent.

The only combination that you will not find in a valid argument is: