PHL 105Y Introduction to Philosophy

1
PHL 105Y Introduction to Philosophy

• For next Mondays class, read the Weston book up
  to page 52
• No tutorials this Friday tutorials will begin
  Friday, September 23.
• If you are here for the first time, welcome. Take
  a syllabus from the desk at the front, as well as
  the reading assignment sheet. The most important
  piece of advice on the syllabus is to do the
  reading before coming to class.
• My office hours today are rescheduled to Friday,
  1-2 pm

2
Tutorial registration

• All students need to sign up for a Friday
  discussion section for this course to do so,
  follow the instructions from the course website
• http//www.utm.utoronto.ca/jnagel/105.htm
• As of this morning, 83/140 students had
  registered
• Tutorials are at 10, 11, 12, 12, 2 and 3,
  starting September 23
• All tutorials are in the North Building room
  numbers are available on the ROSI timetable and
  will also be posted to the website.

3
What is an argument?
4
What is an argument?

• A sequence of premises aimed at establishing a
  conclusion

5
What is an argument?

• A sequence of premises aimed at establishing a
  conclusion
• Ideally if you accept the premises, you should
  accept the conclusion

6
What is an argument?

• A sequence of premises aimed at establishing a
  conclusion
• Ideally if you accept the premises, you should
  accept the conclusion
• Would perfectly rational beings engage in
  arguments with one another?

7
The aim

• To identify some basic rules for analyzing and
  evaluating arguments
• Grasping these rules should also help us to
  construct better arguments of our own

8
Westons rules

• Distinguish premises (starting points) and
  conclusion (what you are trying to prove)
• Present your ideas in a natural order
• Start from reliable premises
• Be concrete and concise
• Avoid loaded language
• Use consistent terms
• Stick to one meaning for each term (avoid fallacy
  of equivocation)

9
Westons rules, continued

• Arguments by example
• Give more than one example
• Use representative examples
• Background information is crucial
• Consider counterexamples
• Arguments by analogy
• Analogy requires a relevantly similar example

10
Finding the conclusion of an argument

• There is no simple mechanical test you can apply
• If you are lucky, the conclusion will be marked
  with words like therefore, consequently or
  so
• Premises are sometimes marked with words like
  for, since, or because
• But you need to try to understand the passage to
  see what the conclusion is. Ask yourself what
  point is this author attempting to make?

11
Hidden premises (and conclusions)

• Sometimes, premises of an argument may be left
  unsaid (especially where they are considered
  particularly obvious)
• Technical name for an argument with a suppressed
  premise enthymeme
• An enthymeme is not a fallacy (but it could be
  vulnerable to attack on the hidden premise it is
  useful to identify hidden premises when they
  might be controversial)

12
Hidden premises

• Smoking causes cancer.
• Cancer shortens your life.
• Therefore, you should not smoke
• What is the hidden premise?
• Should it have been stated?

13
Westons Rule 12, again

• Analogy requires a relevantly similar example.

14
Sample Argument 1 What is the conclusion? What
is the analogy, and is it appropriate?

• The wise person does not deprecate life nor does
  he fear the cessation of life. The thought of
  life is no offense to him, nor is the cessation
  of life regarded as an evil. And even as people
  choose of food not merely and simply the larger
  portion, but the more pleasant, so the wise seek
  to enjoy the time which is most pleasant and not
  merely that which is longest.
• --Epicurus, letter to Menoeceus

15
Sample Argument 2 What is the analogy here?What
is the conclusion? Is it explicitly stated?

• How men, whose plentiful fortunes allow them
  leisure to improve their understandings, can
  satisfy themselves with a lazy ignorance, I
  cannot tell but methinks they have a low opinion
  of their souls, who lay out all their incomes in
  provisions for the body, and employ none of it to
  procure the means and helps of knowledge who
  take great care to appear always in a neat and
  splendid outside, and would think themselves
  miserable in coarse clothes, or a patched coat,
  and yet contentedly suffer their minds to appear
  abroad in a piebald livery of coarse patches and
  borrowed shreds, such as it has pleased chance,
  or their country tailor (I mean the common
  opinion of those they have conversed with) to
  clothe them in.
• --John Locke, An Essay Concerning Human
  Understanding 4.20.6