Exam 10: Deduction and Induction: A Closer Look

Aristotle's works on logic are known as the "organon."

Assume each of the following is a deductive argument. In each case, is the argument valid or invalid? (V or I) -Some football coaches are poets. But no poet knows how to play football. So some football coaches do not know how to play football.

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 movie stars are hamsters. Some movie stars are rock hounds. So …

Mathematical arguments are a type of deductive argument.

If an argument has premises that are likely to be false and a conclusion that is likely to be false, then the argument is weak.

Aristotle was born in the ____ century BC.

Is the argument deductive (D) or inductive (I)? -If the Fleet Foxes are playing, then there will be a crowd. The Fleet Foxes are playing. So there will surely be a crowd.

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

Assume each of the following is a deductive argument. In each case, is the argument valid or invalid? (V or I) -If Sue wins, then Ed will be happy. If Ed is happy, then George will be happy. So if Sue wins, then George will be happy.

Strong or Weak? -Professor Smith wore a bright red tie twice last week. He rarely wears a tie. So he will probably wear a bright red tie next week.

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 the sun is out, it is daytime … Therefore, the sun is not out.

In an analogical argument, all things equal, the more specific the conclusion, the stronger the argument.

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. -Some sasquatches are registered nurses … Therefore, some registered nurses are hairy creatures indeed.

Plato's Academy was located in Athens, Greece.

Is the argument deductive (D) or inductive (I)? -Either we eat dinner at a fast food place, or we cook. We won't eat fast food tonight. So we'll certainly cook.

The following is a valid deductive argument: If it snows, then we will go sledding, just like when we were kids. It is snowing. So certainly we will go sledding, just like when we were kids.

Is the argument deductive (D) or inductive (I)? -If Jan cooks, the dinner will be late. It is not late. Therefore, Jan is certainly not cooking tonight.

The following is a strong argument: Joe has eaten lunch at the taco stand every day for sixty days straight. Tomorrow is an ordinary day. Thus, tomorrow he will probably eat there again.

Is the argument deductive (D) or inductive (I)? -We have only $500 to spend, and a good laptop is at least $400. Therefore, necessarily, we can buy at most one laptop.

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