1. Just the plain facts! PRESENTATION SERIES How to argue for a thesis © Nicholas G. Ashby 2004

2. Background When you write a thesis-based essay, you must do two things: 1. come up with a thesis 2. support your thesis For coming up with a thesis, see the BWC presentation on theses and thesis-statements. For information and tips on supporting your thesis, read on…

3. Supporting your thesis To support your thesis you must argue for it, and that means providing reasons to persuade your readers of its truth.

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

5. Evidence For your supporting argument to be effective: it should include trustworthy evidence it should include trustworthy evidence the evidence should be relevant to the thesis. the evidence should be relevant to the thesis.

6. Evidence Trustworthy evidence: is the most up-to-date evidence available; old data is likely to have been updated by new findings is the most up-to-date evidence available; old data is likely to have been updated by new findings comes from reputable sources; a blind comes from reputable sources; a blind peer-reviewed academic journal is more trustworthy than a popular Internet site, book, magazine or newspaper! peer-reviewed academic journal is more trustworthy than a popular Internet site, book, magazine or newspaper!

7. Pyramid of plausibility Blind Blind peer-reviewed peer-reviewed articles from articles from academic journals. academic journals. Academic books. Documents Academic books. Documents on university or government on university or government websites. websites. Respectable popular periodicals – e.g. Respectable popular periodicals – e.g. Scientific American and The Economist. Scientific American and The Economist. Popular magazines, newspapers, television, radio, Popular magazines, newspapers, television, radio, websites. websites.

8. Evidence Evidence that is relevant: lends credibility to the thesis; if it is easy to imagine that the thesis is false even though the evidence is true or probable, then the evidence is not very relevant to the thesis! lends credibility to the thesis; if it is easy to imagine that the thesis is false even though the evidence is true or probable, then the evidence is not very relevant to the thesis! Tip: evidence could be trustworthy but not relevant, or be relevant but not trustworthy. Make sure that your evidence is both trustworthy AND relevant!

9. Evidence Most evidence is neither fully relevant nor completely irrelevant, but falls somewhere between these two extremes.

10. Evidence The closer the evidence is to being fully relevant, the stronger support it gives to your thesis.

11. Evidence The closer the evidence is to being irrelevant, the weaker support it gives to your thesis.

12. Evidence Evidence that falls more or less in the middle gives moderate support to your thesis.

13. Evidence Obviously, you want your evidence to provide as strong a support for your thesis as possible. But how can you tell if your evidence is giving your thesis weak, moderate, or strong support?!

14. How much support? This can be done by trying to imagine that your thesis is false and the evidence true

15. How much support? Harder to imagine the thesis is false and the evidence true!

16. How much support? Easier to imagine the thesis is false and the evidence true!

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

18. EVIDENCE: Surface temperature records show that Earth’s surface has been warming at an unprecedented rate over the last century, coinciding with industrial development. THESIS: Human activity is largely responsible for global warming. global warming. The thesis is false – there is no global warming. Temperature readings of the atmosphere show no significant increases! Easy to imagine this is true So, the evidence provides only weak support to the thesis!

19. EVIDENCE: 2.5 billion people are at risk + DDT has a devastating effect from malaria, and DDT is the on the environment, causing only really effective way of cancer and sterility, and it is controlling malaria at the spread around the world by moment. weather systems. THESIS: There should be a phased-in worldwide ban on DDT, to give time for effective alternatives to be deployed to give time for effective alternatives to be 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 to imagine this is true So, the evidence gives strong support to the thesis!

20. EVIDENCE: Marijuana is no more People should not be given Marijuana is no more People should not be given harmful than legal drugs, criminal records just because harmful than legal drugs, criminal records just because such as alcohol and tobacco. they possess small amounts such as alcohol and tobacco. they possess small amounts of marijuana intended for of marijuana intended for personal use. personal use. THESIS: The 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 to imagine this is true So, the evidence gives moderate support to the thesis!

21. 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!

22. Frequently asked questions 1. My thesis isn’t very good – how can I improve it? Try to be more specific about why it “isn’t very good.” Your thesis may not be very good if it is trivial or lacking focus (see BWC presentation on theses and thesis-statements for information and advice). Alternatively, your thesis may not be very good if it is not supported by solid evidence. Review the evidence for your thesis to ensure that it is as relevant and trustworthy as possible. If the evidence for your thesis is weak, consider selecting a different thesis.

23. Frequently asked questions 2. I’m having trouble coming up with evidence for my thesis – help! This problem can occur when you come up with a thesis first and look for evidence afterwards. Review your reading and research and reflect on what the information implies. You could use anything implied by the information as a thesis, and use the information as the evidence for it (but see the BWC presentation on theses and thesis-statements first). This problem can also occur if you are not good at doing searches. Don’t be afraid to speak to a librarian for assistance and tutoring.

24. Frequently asked questions 3. I have come up with several theses, but I’m not sure which one to use – help! Lucky you for being in such an enviable position! Start by picking out the most controversial theses. Next, review the trustworthiness and relevance of the evidence for these theses. Finally, select the controversial thesis with the most trustworthy, relevant evidence. If none of your controversial theses have very trustworthy, relevant evidence, select from among your less controversial theses!

25. Frequently asked questions 4. The only evidence I can find is twenty years old – is this a problem? Yes, this is a problem! The older the information, the more untrustworthy it is, because it has likely been updated or superseded. Exceptions include classic texts and seminal works, which are quoted and discussed years, sometimes hundreds of years, after their publication! Even so, twenty-years-old information should not be the ONLY evidence for any thesis! For science essay theses, up-to-date evidence is no more than a few years old, and no more than five to ten years old for humanities essay theses.

26. Other sources and resources Make an appointment for the Bethune Writing Centre (go to Make an appointment for the Bethune Writing Centre (go to Master’s office at 205 Bethune to book a slot, or call 416 736 2100 ext. 22035) Master’s office at 205 Bethune to book a slot, or call 416 736 2100 ext. 22035) Visit York Centre for Academic Writing online resources at: Visit York Centre for Academic Writing online resources at: http://www.arts.yorku.ca/caw/resources.html http://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). Informal logic (2 nd ed.). New York: Macmillan. Call number: BC 71 C68 Pinto, R., Blair, A., & Parr, K. (1993). Reasoning: A practical guide for Canadian students. Scarborough, Ont.: Prentice-Hall. Call number: BC 177 P55

27. Other sources and resources Thomas, S. N. (1997). Practical reasoning in natural language (4 th ed.). New Jersey: Prentice-Hall. Call number: BC 177 T5 Warnick, B., & Inch, E. S. (1998). Critical thinking and communication (3 rd ed.). Boston: Allyn and Bacon. Call number: BC 177 W35