2.3: Strength & Cogency

2.3: Strength & Cogency

1. Everyone in Bob's office has the flu.
2. Bob's family has the flu.
3. Bob's friends have the flu.
4. So, Bob has the flu as well.

2.3: Strength & Cogency

• Strong inductive argument: provides very good evidence for the conclusion (the conclusion is very likely, given the premises).
• Weak inductive argument: provides poor evidence for the conclusion (the conclusion is not particularly likely, given the premises).

2.3: Strength & Cogency

1. Poodles can fly.
2. Golden retrievers can fly.
3. Bulldogs can fly.
4. Labradors can fly.
5. Therefore, all dogs can fly.

2.3: Strength & Cogency

1. Lions can talk.
2. Cheetahs can talk.
3. So, all animals can talk.

2.3: Strength & Cogency

• An inductive argument is cogent just in case it is strong and all of the premises are true.

2.3: Strength & Cogency

1. Poodles can fly.
2. Golden retrievers can fly.
3. Bulldogs can fly.
4. Labradors can fly.
5. Therefore, all dogs can fly.

2.3: Strength & Cogency

Key Concepts

• Strong/Weak
• Cogent/Non-cogent