9.23 Classify the kind of causality intended by the following statements:

(a) Flipping the wall switch will cause the light to go on.

(b) Closing the electricity supply from the main lines will cause the light to go off.

(c) Making a lot of noise will cause the neighbors to complain.

(d) Pulling the trigger will cause the gun to fire.

(e) Raising the temperature of a gas will cause an increase in its volume.

(f) Raising the temperature of the freezer above +32 degrees Fahrenheit will cause

the ice cubes in the freezer to melt.

(g) Killing the President will cause new presidential elections.

(h) Raising the temperature in the environment will cause the death of many

plants.

9.24 Suppose we are looking for the necessary cause of a certain disease E, and we
have by using our backgrcund knowledge and expertise formulated a list of five viral
agents, V, through V,, which we suspect may cause E. We examine a number of
patients with E and check to see which of the suspected causes is present in each case.

9.25 A number of people have eaten a picnic lunch which included five foods, F,
through Fs. Many of them are suffering from food poisoning. It is assumed that among
the five foods is one which is sufficient to produce the poisoning among this group of
people. Now suppose that we find two individuals, one of whom has eaten all five foods
and is suffering from food poisoning and the other of whom has eaten all but Fl and
is feeling fine.

9.26 Suppose that a student in a colle,ge dormitory notices a peculiar sort of
interference on her television set. She has seen similar kinds of interference before and
suspects that its necessary and sufficient cause (provided the television is on) is the
nearby operation of some electrical appliance. This leads her to formulate the
following list of suspected causes:
S = electric shaver
H = hair dryer
D = clothes dryer
W = washing machine
She now observes which appliances are operating in nearby rooms while her television
is on.

 

 

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