1. Induction, Analogy, Causation

2. There are two kinds of arguments: inductive and deductive Inductive arguments are much more common, but it is also much more difficult to determine their logical form. Deductive arguments are rare, though they are logically much more simple.

3. Inductive arguments: Typically appeal to experience or experimental data. Commonly involve forecast about future events or generalizations about things, people, and events. Provide conclusions with some degree of certainty.

4. Examples of inductive arguments: Commercial airplanes are some of the safest modes of transportation. So, it is not likely that anything bad will happen to me on my flight. I have a gene that many people with hair loss have. I will probably lose my hair as I get older.

5. Induction and generalization Generalizations are a kind of inductive argument. Good generalizations do the following: – Use an adequate number of examples. – Use examples that are representative. – Provide context. All inductive arguments rely on the “inductive principle”: – The inductive principle assumes that some really basic features of the world will continue unchanged.

6. More inductive arguments If you do your homework and study, you’ll get a good grade. If you take care of yourself and see the doctor when you are ill, you will live a long life. The sun will rise tomorrow. It always has. Republicans generally favor lower taxes. Given that you’re a Republican, you probably favor lower taxes.

7. Deductive arguments: Deductive arguments produce conclusions that are absolutely certain. Most logic courses focus on deductive arguments because the logic is much easier than the logic of inductive arguments. However, one may question whether the knowledge gained through deductive arguments is new, since the information in the conclusion has to be included in the premises.

8. Examples of deductive arguments: Horses are mammals. Mammals produce offspring through live birth. Horses produce offspring through live birth. Paul is seven feet tall. People who are seven feet tall make good basketball players. Paul willmake a good basketball player.

9. Arguments by analogy Analogies are very useful to illustrate difficult, abstract, or intangible things. But they have their limits.

10. What makes an analogy work? The analogy must be similar in the relevant way; differences between two terms of the analogy must not be central to the analogy. One term of the analogy must be clearer than the other so that the one explains the other. The observed features of the analogy must be accurate.

11. At some point… … all analogies break down. No two terms of an analogy can be perfectly alike; otherwise it wouldn’t be an analogy! You must be aware of how the two terms differ and note that this difference does not undermine the analogy.

12. Arguments about causes

13. Introducing causality is very tempting Causes explain their effects; when you are looking for an explanation, a cause seems like a good candidate. Talk about causality seems scientific. … but you should be aware that causality can be very complex.

14. Causality and Correlation Two things are correlated whenever the existence of one regularly accompanies the existence of the other. Correlation is necessary for causation, but it does not imply causation. Examples: – Sleeping with your shoes on is strongly correlated with waking up with a headache. – As ice cream sales increase, so does the frequency of drowning deaths. – Obesity is correlated with automobile use.

15. Multiple causes Even if you think you have discovered a cause of some effect, it may not be the only one. Most complex events have multiple causes: – Health – Weather – Success Complete and partial causes: – Instead of talking about “the” cause, philosophers prefer to talk about either complete or partial causes. – The complete causes necessitate the effect. – Partial causes contribute to the effect.

16. Inference to the best explanation What is the most likely explanation for this event? Recognize that most explanations are preliminary and partial; be prepared to revise. Consider alternative explanations. Avoid superstition, unlikely causal powers, or “God of the gaps” explanations. – Just because we don’t know the cause of something doesn’t mean it’s beyond explanation.