Who stole the horse? What can you work out from the following clues about the crime.
Syllogisms
Truth & validity
Structure of arguments
Using venn diagrams
3. Inductive reasoning
Making generalisations about the world
Is there a danger to generalisations? Look at the list of 14 generalisations and order them from most reliable to least
What makes a good generalisation? You have 5 minutes in your pairs or small groups to think of "5 rules for making good generalisations".
Check yours against the Book
Listen to the story of the Inductive turkeys & then discuss the following questions with a partner or small group:
a. To what extent do human beings sometimes act like the turkeys in the story? b. The turkeys turned out to be wrong, but do you think that their belief was reasonable? c. What does this suggest to you about the relationship between reason and truth? d. When your dog gets excited when he sees you getting his lead out, do you think he is using inductive reasoning to predict you are going to take him for a walk?
The point: Well confirmed generalisations can can fail us e.g. Newton's laws of motion. It is possible that tomorrow, for the first time, that everyday regularities may break down
4. Informal reasoning
Post hoc ergo propter hoc - Assuming one thing causes another just because one follows another e.g. murder rate going up after the abolition of capital punishment
Ad ignoratium - Claiming that something is true because it cannot be proved to be false e.g. McCarthy witch hunts said 'there is nothing in the files to disprove his communist connection'
Hasty generalisation - generalising from insufficient evidence e.g. all French people are rude
Ad hominen fallacy - Attacking/supporting the peson rather than the argument e.g. saying you are too young to have an opinion on whether there should be a world government, Einstein believed in world government so it must be a good thing
Circular reasoning - assuming the truth of what you are supposed to be proving e.g. 'I know Jesus was the Son of God because he said he was, and the Son of God would not lie.'
Special pleading - using double standards to excuse an individual or group e.g. 'I know there is a drought and we need to save water, but I am putting my prize flowers in a competition next week and I need to give them plenty of water.'
Equivocation - Using language ambigiously e.g 'A hamburger is better than nothing, Nothing is better than good health, Therefore a hamburger is better than good health.'
False analogy - Assuming that because two things are alike in one way that they are alike in other respects e.g. 'Just as in time the gentle rain can wear down the tallest mountains, so, in human life, all rpoblems can be solved by patience and quiet perseverance.'
False dilemma - Assuming that only a limited number of alterntaives exist e.g. 'Do those who advocate an increase in military spending want to see our schools closed?'
Loaded question - A question that is biased because it contains a built in assumption e.g. 'Do you always cheat in exams?'
Activity
In each of the following cases, decide which best applies to the argument.
a.Since strict gun control laws were introduced in Dodge City, the crime rate has risen. This shows that gun control does nothing to reduce crime. b. Miss Bunker said she trusted me, and she must be telling the truth because she wouldn’t lie to someone that she trusted. c.The ends justifies the means. After all, if you want to make omelettes, you have to break eggs d.That can’t be right, non of my friends would believe it. e. Since many great scientists have believed in God, there must be some truth in religion f. Roxanna and Jordan got on very well on their two dates together. They are clearly well suited and should get married. g. Do you want to be part of the solution, or part of the problem? h. “I agree that you shouldn’t copy mp3s illegally, but I’ve only copied a few and I do buy tracks sometimes.” i. The average UK family has 2.5 children. The Smiths are average people, they must have 2.5 kids. j. Since no-one has been able to prove that God didn’t create the universe, we must conclude that God did make everything. k. Are all your family stupid, or is it just you? l. No scandal has ever touched Mr Rick Perry. He must be a clean living and honest man m. Just as you are more likely to take care of a car that you own rather than a car that you rent, a slave owner would look after a slave better than an employer would look after their worker n.To ignore the possibility that Joseph Patterson-Roberts landed the first person on the moon just because nobody has heard of Joseph Patterson-Roberts’s space program is arrogant. If we are unaware of something does not mean that it never happened
Conclusions
Rationalist philosophers like Rene Descartes believed that reason was a way of knowing that can give us certainty.
But it is only as certain as the premises on which it is based - and it is always possible that we have reasoned badly in arguing from premises to conclusions.
We also raised various philosophical doubts about induction and deduction but in practice it is difficult to see how we can do without these two ways of reasoning
It seems that reason like other ways of knowing is a double edged tool.
We need to reason to develop consistent beliefs about the world but we can become trapped in the ‘prison of logic’ and this can stifle our creativity.
Furthermore, reason is not appropriate in every situation, and if someone is too rational they may simply come across as a cold and unfeeling robot.
2. Deductive reasoning
3. Inductive reasoning
- Making generalisations about the world
- Is there a danger to generalisations? Look at the list of 14 generalisations and order them from most reliable to least
- What makes a good generalisation? You have 5 minutes in your pairs or small groups to think of "5 rules for making good generalisations".
- Check yours against the Book
- Listen to the story of the Inductive turkeys & then discuss the following questions with a partner or small group:
a. To what extent do human beings sometimes act like the turkeys in the story?b. The turkeys turned out to be wrong, but do you think that their belief was reasonable?
c. What does this suggest to you about the relationship between reason and truth?
d. When your dog gets excited when he sees you getting his lead out, do you think he is using inductive reasoning to predict you are going to take him for a walk?
4. Informal reasoning
- Post hoc ergo propter hoc - Assuming one thing causes another just because one follows another e.g. murder rate going up after the abolition of capital punishment
- Ad ignoratium - Claiming that something is true because it cannot be proved to be false e.g. McCarthy witch hunts said 'there is nothing in the files to disprove his communist connection'
- Hasty generalisation - generalising from insufficient evidence e.g. all French people are rude
- Ad hominen fallacy - Attacking/supporting the peson rather than the argument e.g. saying you are too young to have an opinion on whether there should be a world government, Einstein believed in world government so it must be a good thing
- Circular reasoning - assuming the truth of what you are supposed to be proving e.g. 'I know Jesus was the Son of God because he said he was, and the Son of God would not lie.'
- Special pleading - using double standards to excuse an individual or group e.g. 'I know there is a drought and we need to save water, but I am putting my prize flowers in a competition next week and I need to give them plenty of water.'
- Equivocation - Using language ambigiously e.g 'A hamburger is better than nothing, Nothing is better than good health, Therefore a hamburger is better than good health.'
- False analogy - Assuming that because two things are alike in one way that they are alike in other respects e.g. 'Just as in time the gentle rain can wear down the tallest mountains, so, in human life, all rpoblems can be solved by patience and quiet perseverance.'
- False dilemma - Assuming that only a limited number of alterntaives exist e.g. 'Do those who advocate an increase in military spending want to see our schools closed?'
- Loaded question - A question that is biased because it contains a built in assumption e.g. 'Do you always cheat in exams?'
Activity- In each of the following cases, decide which best applies to the argument.
a.Since strict gun control laws were introduced in Dodge City, the crime rate has risen. This shows that gun control does nothing to reduce crime.b. Miss Bunker said she trusted me, and she must be telling the truth because she wouldn’t lie to someone that she trusted.
c.The ends justifies the means. After all, if you want to make omelettes, you have to break eggs
d.That can’t be right, non of my friends would believe it.
e. Since many great scientists have believed in God, there must be some truth in religion
f. Roxanna and Jordan got on very well on their two dates together. They are clearly well suited and should get married.
g. Do you want to be part of the solution, or part of the problem?
h. “I agree that you shouldn’t copy mp3s illegally, but I’ve only copied a few and I do buy tracks sometimes.”
i. The average UK family has 2.5 children. The Smiths are average people, they must have 2.5 kids.
j. Since no-one has been able to prove that God didn’t create the universe, we must conclude that God did make everything.
k. Are all your family stupid, or is it just you?
l. No scandal has ever touched Mr Rick Perry. He must be a clean living and honest man
m. Just as you are more likely to take care of a car that you own rather than a car that you rent, a slave owner would look after a slave better than an employer would look after their worker
n.To ignore the possibility that Joseph Patterson-Roberts landed the first person on the moon just because nobody has heard of Joseph Patterson-Roberts’s space program is arrogant. If we are unaware of something does not mean that it never happened
Conclusions
Resources
Video