Just the plain facts!Just the plain facts!PRESENTATION SERIESPRESENTATION SERIES

How to argue for a thesisHow to argue for a thesis

© Nicholas G. Ashby 2004 © Nicholas G. Ashby 2004

BackgroundBackgroundWhen you write a thesis-based essay, youWhen you write a thesis-based essay, youmust do two things:must do two things:

1.1. come up with a thesiscome up with a thesis2.2. support your thesissupport your thesis

For coming up with a thesis, see the BWCFor coming up with a thesis, see the BWCpresentation on theses and thesis-presentation on theses and thesis-

statements.statements.For information and tips on supporting For information and tips on supporting

youryourthesis, read on…thesis, read on…

Supporting your thesisSupporting your thesis

To support your thesis you must argue for To support your thesis you must argue for it,it,

and that means providing reasons to and that means providing reasons to persuadepersuade

your readers of its truth.your readers of its truth.

Supporting your thesisSupporting your thesis How well you support your thesis shows How well you support your thesis shows

how good (or bad!) you are at critical how good (or bad!) you are at critical thinking. thinking. An essay with An essay with a thesis that is a thesis that is not well-argued fornot well-argued for will not get the best will not get the best grade, no matter how interesting the grade, no matter how interesting the thesis is.thesis is.

EvidenceEvidence

For your supporting argument to be For your supporting argument to be effective:effective:

it should include it should include trustworthytrustworthy evidence evidence

the evidence should be the evidence should be relevantrelevant to the to the thesis.thesis.

EvidenceEvidence

Trustworthy evidence:Trustworthy evidence:

is the most up-to-date evidence is the most up-to-date evidence available; available; old data is likely to have old data is likely to have been updated by new findingsbeen updated by new findings

comes from reputable sources; comes from reputable sources; a blinda blind peer-reviewed academic journal is peer-reviewed academic journal is

more trustworthy than a popular more trustworthy than a popular Internet site, book, magazine or Internet site, book, magazine or newspaper!newspaper!

Pyramid ofPyramid ofplausibility plausibility BlindBlind

peer-reviewedpeer-reviewed articles fromarticles from academic journals. academic journals.

Academic books. DocumentsAcademic books. Documents on university or government on university or government websites.websites.

Respectable popular periodicals – e.g.Respectable popular periodicals – e.g. Scientific AmericanScientific American and and The EconomistThe Economist..

Popular magazines, newspapers, television, radio,Popular magazines, newspapers, television, radio, websites.websites.

EvidenceEvidence

Evidence that is relevant:Evidence that is relevant:

lends credibility to the thesis; lends credibility to the thesis; if it is easy to if it is easy to imagine that the thesis is false even though the imagine that the thesis is false even though the evidence is true or probable, then the evidence evidence is true or probable, then the evidence is not very relevant to the thesis!is not very relevant to the thesis!

TipTip: evidence could be trustworthy but not : evidence could be trustworthy but not relevant,relevant,

or be relevant but not trustworthy. or be relevant but not trustworthy. Make sure thatMake sure that

your evidence is both trustworthy AND relevant!your evidence is both trustworthy AND relevant!

EvidenceEvidence

Most evidence is neither fully relevant Most evidence is neither fully relevant nornor

completely irrelevant, but falls completely irrelevant, but falls somewheresomewhere

between these two extremes. between these two extremes.

EvidenceEvidence

The closer the evidence is to being fullyThe closer the evidence is to being fully

relevant, the stronger support it gives torelevant, the stronger support it gives to

your thesis. your thesis.

EvidenceEvidence

The closer the evidence is to being The closer the evidence is to being irrelevant,irrelevant,

the weaker support it gives to your the weaker support it gives to your thesis. thesis.

EvidenceEvidence

Evidence that falls more or less in the Evidence that falls more or less in the middlemiddle

gives moderate support to your thesis.gives moderate support to your thesis.

EvidenceEvidence

Obviously, you want your evidence to Obviously, you want your evidence to provideprovide

as strong a support for your thesis as as strong a support for your thesis as possible. possible.

But how can you tell if your evidence is giving your thesis weak, moderate, or

strong support?!

How much support?How much support?

This can be done by trying to imagine that your thesis is false and the evidence true

How much support?How much support?

Harder to imagine the thesis is falseand the evidence true!

How much support?How much support?

Easier to imaginethe thesis is falseand the evidence true!

How much support?How much support?Between easy and hard to imagine the thesis is false and the evidence true!

EVIDENCE:EVIDENCE:

Surface temperature records show that Earth’s Surface temperature records show that Earth’s surfacesurface

has been warming at an unprecedented rate has been warming at an unprecedented rate over theover the

last century, coinciding with industrial last century, coinciding with industrial development. development.

THESIS:THESIS: Human activity is largely Human activity is largely responsible forresponsible for

global warming. global warming. The thesis is false – there is no global warming. Temperature readings of the atmosphere show no significant increases!

Easy toimaginethis istrue

So, the evidenceprovides only weak support to the thesis!

EVIDENCE:EVIDENCE:2.5 billion people are at risk + DDT has a devastating

effectfrom malaria, and DDT is the on the environment,

causingonly really effective way of cancer and sterility, and

it is controlling malaria at the spread around the world

by

moment. weather systems.moment. weather systems.

THESIS:THESIS: There should be a phased-in worldwide ban on There should be a phased-in worldwide ban on DDT,DDT,

to give time for effective alternatives to be to give time for effective alternatives to be deployed deployed

The thesis is false – DDT should be banned immediately. Its terrible effects on the global environment are more important than the 2.5 billion people at risk.

Hard toimaginethis istrue

So, theevidencegives strong support tothe thesis!

EVIDENCE:EVIDENCE:

Marijuana is no more People should not be Marijuana is no more People should not be given given

harmful than legal drugs, criminal records just harmful than legal drugs, criminal records just becausebecause

such as alcohol and tobacco. they possess small such as alcohol and tobacco. they possess small amountsamounts

of marijuana intended for of marijuana intended for

personal use.personal use.

THESIS: THESIS: The possession and use of small amounts ofThe possession and use of small amounts of

marijuana should be legalized. marijuana should be legalized.

The thesis is false –it makes no sense to legalize even small quantities of yet another harmful drug!

Between easy and hard toimaginethis istrue

So, theevidencegivesmoderatesupport tothe thesis!

Practice!Practice!

Like anything else, it takes practice to become good at imagining how the thesis could be false and the evidence true, and deciding how easy, moderate or hard it is to believe what you imagine!

Frequently asked questionsFrequently asked questions1. My thesis isn’t very good – how can I1. My thesis isn’t very good – how can Iimprove it?improve it?Try to be more specific about why it “isn’t very Try to be more specific about why it “isn’t very

good.” good.”

Your thesis may not be very good if it is trivial orYour thesis may not be very good if it is trivial orlacking focus (see BWC presentation on theses andlacking focus (see BWC presentation on theses andthesis-statements for information and advice).thesis-statements for information and advice).

Alternatively, your thesis may not be very good if it isAlternatively, your thesis may not be very good if it isnot supported by solid evidence. not supported by solid evidence. Review the Review the

evidenceevidencefor your thesis to ensure that it is as relevant andfor your thesis to ensure that it is as relevant andtrustworthy as possible. If the evidence for your trustworthy as possible. If the evidence for your

thesisthesisis weak, consider selecting a different thesis.is weak, consider selecting a different thesis.

Frequently asked questionsFrequently asked questions2. I’m having trouble coming up with2. I’m having trouble coming up withevidence for my thesis – help!evidence for my thesis – help!This problem can occur when you come up with aThis problem can occur when you come up with athesis first and look for evidence afterwards. thesis first and look for evidence afterwards.

ReviewReviewyour reading and research and reflect on what theyour reading and research and reflect on what theinformation implies. You could use anything impliedinformation implies. You could use anything impliedby the information as a thesis, and use theby the information as a thesis, and use theinformation as the evidence for it (but see the BWCinformation as the evidence for it (but see the BWCpresentation on theses and thesis-statements first).presentation on theses and thesis-statements first).This problem can also occur if you are not good atThis problem can also occur if you are not good atdoing searches. Don’t be afraid to speak to a doing searches. Don’t be afraid to speak to a

librarianlibrarianfor assistance and tutoring. for assistance and tutoring.

Frequently asked questionsFrequently asked questions

3. I have come up with several theses,3. I have come up with several theses,

but I’m not sure which one to use – but I’m not sure which one to use – help!help!

Lucky you for being in such an enviable position!Lucky you for being in such an enviable position!

Start by picking out the most controversial theses.Start by picking out the most controversial theses.

Next, review the trustworthiness and relevance of Next, review the trustworthiness and relevance of thethe

evidence for these theses. Finally, select theevidence for these theses. Finally, select the

controversial thesis with the most trustworthy,controversial thesis with the most trustworthy,

relevant evidence. relevant evidence. If none of your controversialIf none of your controversial

theses have very trustworthy, relevant evidence,theses have very trustworthy, relevant evidence,

select from among your less controversial theses!select from among your less controversial theses!

Frequently asked questionsFrequently asked questions4. The only evidence I can find is twenty4. The only evidence I can find is twentyyears old – is this a problem?years old – is this a problem?Yes, this is a problem! The older the information, theYes, this is a problem! The older the information, themore untrustworthy it is, because it has likely beenmore untrustworthy it is, because it has likely beenupdated or superseded. Exceptions include classicupdated or superseded. Exceptions include classictexts and seminal works, which are quoted andtexts and seminal works, which are quoted anddiscussed years, sometimes hundreds of years, afterdiscussed years, sometimes hundreds of years, aftertheir publication! Even so, twenty-years-oldtheir publication! Even so, twenty-years-oldinformation should not be the ONLY evidence for anyinformation should not be the ONLY evidence for anythesis! For science essay theses, up-to-date evidencethesis! For science essay theses, up-to-date evidenceis no more than a few years old, and no more thanis no more than a few years old, and no more thanfive to ten years old for humanities essay theses.five to ten years old for humanities essay theses.

Other sources and resourcesOther sources and resources Make an appointment for the Bethune Writing Centre (go Make an appointment for the Bethune Writing Centre (go

to to Master’s office at 205 Bethune to book a slot, or call 416 Master’s office at 205 Bethune to book a slot, or call 416

736 2100 ext. 22035)736 2100 ext. 22035)

Visit York Centre for Academic Writing online resources Visit York Centre for Academic Writing online resources at:at:

http://www.arts.yorku.ca/caw/resources.htmlhttp://www.arts.yorku.ca/caw/resources.html

The following books may be useful:The following books may be useful:

Copi, I., & Burgess-Jackson, K. (1992). Copi, I., & Burgess-Jackson, K. (1992). Informal logicInformal logic (2 (2ndnd ed.).ed.).

New York: Macmillan. New York: Macmillan. Call number: BC 71 C68Call number: BC 71 C68

Pinto, R., Blair, A., & Parr, K. (1993). Pinto, R., Blair, A., & Parr, K. (1993). Reasoning: A practicalReasoning: A practicalguide for Canadian studentsguide for Canadian students. Scarborough, Ont.: Prentice-. Scarborough, Ont.: Prentice-

Hall.Hall.Call number: BC 177 P55Call number: BC 177 P55

Other sources and resourcesOther sources and resources

Thomas, S. N. (1997). Thomas, S. N. (1997). Practical reasoning in natural Practical reasoning in natural languagelanguage

(4(4thth ed.). New Jersey: Prentice-Hall. ed.). New Jersey: Prentice-Hall. Call number: BC 177 Call number: BC 177 T5T5

Warnick, B., & Inch, E. S. (1998). Warnick, B., & Inch, E. S. (1998). Critical thinking andCritical thinking and

communicationcommunication (3 (3rdrd ed.). Boston: Allyn and Bacon. ed.). Boston: Allyn and Bacon.

Call number: BC 177 W35Call number: BC 177 W35