Premise 3: Too many males will create social problems.
Main conclusion: We should discourage sex selection techniques.
结论: Falstaff hasn’t dieted.
Different Uses of Premises
“It is right to ban cigarette advertising because it encourages young people to start smoking. But even if it had no such influence on young people, it would be right to ban it because it could give existing smokers the mistaken impression that their habit is socially acceptable.”
We can call these:
Joint Premises
&
Independent Premises
Different Conclusions
What is the structure of this argument?
“A majority of prospective parents would prefer to have sons rather than
Definition of an Argument
An argument is….
A set of propositions (命题) where—
One is said to be true,
AND
The other(s) are being given as reasons to believe the truth of that one.
OR
Have a relationship but not the same kind as arguments do
这些句子是不是立论?
21%的空气是氧气.
哈尔滨在黑龙江省.
这些呢?
21%的空气是氧气。
因此哈尔滨在黑龙江省。
Argument is not an innate quality (天生的特点) of propositions. Rather, it’s something we do with propositions.
Different Conclusions
Premise 1: Most prospective parents prefer sons to daughters.
Premise 2/Intermediate conclusion: If people can choose the sex of their child, there will be more males than females.
第一前提: Cigarette advertising encourages young people to start smoking.
第二前提: Cigarette advertising gives smokers the impression smoking is socially acceptable.
Witches (女巫们) float because witches are made of wood and wood floats.
Since Jesse James left town with his gang (一帮), things have been a lot quieter.
Different Uses of Premises
Lecture 1: Introduction to Argument
Why learn critical thinking skills?
*clarify our thinking *advance our thinking * see the implications of and relationships between our ideas and beliefs * identify the flaws in our own and others’ thinking
In the second example, the premises give independent reasons for the conclusion. If we removeபைடு நூலகம்a premise, the conclusion still has some support.
Different Uses of Premises
IMPORTANT: An argument is a set of propositions, but not all sets of propositions are arguments.
Sets of propositions that are not arguments may:
Have no relationship to each other at all
Which ones are arguments?
At about 11am the rain stopped and the clouds parted. Then the sun came out.
Since Chengdu is west of Wuhan and Urumqi is west of Chengdu, Urumqi is west of Wuhan.
结论: It is right to ban cigarette advertising.
Different Uses of Premises
In the first example, the premises build on each other, leading to the conclusion. But if we remove a premise, the conclusion loses all support.
今天星期二。山谷老师每个星期二穿灰色的马甲。因此 山谷老师今天会穿灰色的马甲。 It is Tuesday. Glenn always wears a grey waistcoat on Tuesday, so Glenn will be wearing a grey waistcoat today.
People who diet lose weight. Since Falstaff hasn’t lost weight, he cannot have dieted.
第一前提: People who diet lose weight.
第二前提: Falstaff hasn’t lost weight.
It is Tuesday. Glenn always wears a grey waistcoat on Tuesday, so Glenn will be wearing a grey waistcoat today.
结论是什么？ 前提是什么?
今天星期二。
山谷老师每个星期二穿灰色的马甲。
山谷老师今天会穿灰色的马甲。
daughters. So, if people can choose the sex of their child, it is likely that eventually there will be many more males than females in the population. A preponderance of males in the population is likely to produce serious social problems. Therefore, we should discourage the use of techniques which enable people to choose the sex of their child.”
Lessons from Monty Python
- ‘Argument is not just contradiction.’ - ’Argument is an intellectual process.’ - ‘Argument is a collected series of statements to establish a definite proposition.’
这个立论有什么主张?
Conclusion (结论) : the proposition said to be true
Premises (前提) : the proposition(s) being offered as reasons to believe the conclusion
今天星期二。山谷老师每个星期二穿灰色的马甲。因此 山谷老师今天会穿灰色的马甲。