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6
STUDIO
You will be far better prepared if you have acquired the habit of asking yourself a
whole range critical questions: What is the conclusion? Does the conclusion follow
from the reasons? Is anything assumed beyond what is stated? How to challenge or
support this argument?
Read every answer choice before selecting the best response.
• A longer passage of more than one paragraph followed by three questions designed
to check reading comprehension; numerical data may be included.
1.3
•
Understanding argument 3: example argument
Argument: Motorway speed limits should be increased to 80 mph. The current limit
of 70 mph was introduced in 1965 when cars were less well engineered than today.
Modern cars are designed for speeds well in excess of 80 mph so there is no need to
restrict motorway speeds to 70 mph.
Conclusion
: Motorway speed limits should be increased to 80 mph.
Evidence
(taken as fact): Modern cars are better engineered.
Evidence
(taken as fact): They are designed for speeds well over 80 mph.
Assumption
(can be challenged): Driving at 80 mph is safe if the car is designed
to do it.
The above argument can be weakened by contradictory evidence or strengthened by
supportive evidence. For example:
• Significantly weakening
:
It may be the case that motor vehicle accidents on motor-
ways usually involve speeds in excess of the current limit (challenges a questionable
assumption).
• Significantly strengthening
: It may be the case that most accidents are not caused by
speeding (supports 70 mph+).
• Slightly weakening
: It may be the case that higher speeds lead to more serious acci-
dents (true but outside scope of argument).
• Slightly strengthening
: It may be the case that there have been major improvements in
highway engineering since 1965 (true but outside scope of argument).
• Inference
: Increasing the motorway speed limit to 80 mph will not lead to more acci-
dents (main thrust of argument).
• Irrelevant
: Carbon dioxide emissions will increase if the speed limit is raised (true
but outside scope of argument).
1.4
•
Critical thinking: Venn diagrams and logic statements
Let’s make an example of
Venn diagrams
. 48 patients attend a chest clinic; 29 have
asthma (A), 30 have bronchitis (B) and 8 have neither disease. How many patients