Inductive and Deductive Reasoning

Determine if the following deductive argument is valid or invalid:

1. 1. Baseball is a pastime.

2. 2. All pastimes are enjoyable.

3. _______________________

4. 3. Therefore, baseball is enjoyable

• Valid

• Invalid

Determine whether the following deductive argument is sound or unsound:

• Sound

• Unsound

Answer explanation

This question is interesting. In reality the Taj Mahal IS shorter than the Eiffel Tower, so you may think that this is a sound argument. However the structure of the argument is invalid. A sound argument must be true and valid -therefore this argument is unsound.

Determine whether the following inductive argument is strong or weak:

• Strong

• Weak

Determine whether the following inductive argument is cogent or not cogent:

1. 1. Insects are capable of rational reflection.

2. 2. Beings capable of rational reflection can communicate with each other.

3. _____________________________________________

4. 3. Therefore, insects are capable of communicating with each other.

• Cogent

• Not Cogent

Answer explanation

Be careful here. Cogency in inductive arguments requires that the premises be true. Insects are not capable of rational reflection.

All cats have a keen sense of smell. Fluffy is a cat, so Fluffy has a keen sense of smell.

• Deductive

• Inductive

Maximilian is a shelter dog. He is happy. All shelter dogs are happy.

• Deductive

• Inductive

Maximillian is a shelter dog. All shelter dogs are happy. Therefore, he is happy.

• Inductive

• Deductive

My mother is Irish. Everyone from Ireland has blond hair. Therefore, my mother has blond hair.

• Deductive

• Inductive

The first lipstick I pulled from my bag is red. All lipsticks in my bag are red. Therefore, the second lipstick I pull from my bag will be red, too.

• Deductive

• Inductive

My mother is Irish. She has blond hair. Therefore, everyone from Ireland has blond hair.

• Deductive

• Inductive