Critical Reasoning for Beginners: week...
Transcript of Critical Reasoning for Beginners: week...
![Page 1: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/1.jpg)
Critical Reasoning for Beginners: week one
Marianne Talbot Department for Continuing Education University of Oxford Michaelmas 2009
![Page 2: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/2.jpg)
Today we shall be looking at:
(i) the nature of arguments
(ii) how to recognise arguments
![Page 3: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/3.jpg)
http://www.youtube.com/watch?v=teMlv3ripSM
![Page 4: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/4.jpg)
Definition: ‘Argument’
…. a set of sentences such that…
…. one of them is being said to be true…
…. the other(s) are being offered as reasons for believing the truth of the one.
![Page 5: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/5.jpg)
An argument:
It is Friday, Marianne always wears jeans on Friday so Marianne will be wearing jeans today.
Q1: List the sentences that make up this argument
![Page 6: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/6.jpg)
It is Friday
Marianne always wears jeans on Friday
Marianne will be wearing jeans today
![Page 7: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/7.jpg)
Conclusion: the sentence being said to be true
Premises: the sentence(s) being offered as reason(s) for believing the one
![Page 8: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/8.jpg)
An argument:
It is Friday, Marianne always wears jeans on Friday so Marianne will be wearing jeans today.
Q2: Identify the conclusion of the argument Q3: Identify the premises of the argument
![Page 9: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/9.jpg)
An argument:
It is Friday, Marianne always wears jeans on Friday so Marianne will be wearing jeans today.
The conclusion is in red The premises are in green
![Page 10: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/10.jpg)
It is important to distinguish arguments from sets of sentences
![Page 11: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/11.jpg)
Sets of sentences that are not arguments might:
a) have no relation at all between them;
b) have between them a relation other than that characterising an argument
![Page 12: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/12.jpg)
A set of sentences that isn’t an argument:
The sea is salt Melbourne is in Australia
![Page 13: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/13.jpg)
But note how easy it is to make it an argument…..
The sea is salt Therefore Melbourne is in Australia
Arguing is something we do with sentences
![Page 14: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/14.jpg)
Which of these sets of sentences are arguments?
1. Towards lunchtime clouds formed and the sky blackened. Then the storm broke.
2. Since Manchester is north of Oxford and Edinburgh is north of Manchester, Edinburgh is north of Oxford.
3. Witches float because witches are made of wood and wood floats.
4. Since Jesse James left town, taking his gang with him, things have been a lot quieter.
adapted from Robert J. Fogelin, Understanding Arguments
![Page 15: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/15.jpg)
There are often words that suggest a set of sentences is an argument:
Since, therefore……
Can you think of any more?
![Page 16: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/16.jpg)
It is also important to distinguish arguments from assertions
![Page 17: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/17.jpg)
An argument is a set of sentences, one of which is being asserted;
An assertion is a single sentence (possibly complex) that is being expressed in assertoric mode.
![Page 18: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/18.jpg)
Which of the following sentences are (or could be) assertions:
1. The room is hot
2. Is the room hot?
3. Turn the heat up!
![Page 19: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/19.jpg)
Beware: some assertions look very like arguments:
If it is snowing the mail will be late
How do we know that this is not an argument?
![Page 20: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/20.jpg)
Assertions are either true or false…
…but arguments are neither true nor false…
…arguments are either good or bad…
![Page 21: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/21.jpg)
…a good argument is one in which:
(a) the conclusion follows from the premises;
(b) the premises are all true.
![Page 22: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/22.jpg)
Note:
as logicians we are less interested in the truth of the premises of an argument…
…than we are in the relation of ‘following from’
![Page 23: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/23.jpg)
One of these is a good argument, one bad, (when we consider the relation of ‘following from’) which is which?
Argument One: If it is Monday the lecture will finish at 3.30 It is Monday Therefore the lecture will finish at 3.30
Argument Two: If it is Monday the lecture will finish at 3.30 The lecture will finish at 3.30 Therefore it is Monday
![Page 24: Critical Reasoning for Beginners: week onemedia.podcasts.ox.ac.uk/conted/critical_reasoning/talbotcr01.pdfCritical Reasoning for Beginners: week one Marianne Talbot Department for](https://reader036.fdocuments.in/reader036/viewer/2022062504/5ae215797f8b9a495c8b9eba/html5/thumbnails/24.jpg)
Next week we shall be looking at the many different sorts of argument there are, and learning how to distinguish them from each other