CLAIMS: THE KEY ELEMENTS OF REASONING 17case, is determined by the different value of'all', 'some', and 'few'. Scope is not just
about numbers. It can also be seen in claims about, for example, a geographic area
('Most of Western Australia is uninhabited') or time ('For much of its history,
Australia was not populated by white people').
Certainty is another characteristic of all claims. Whether explicitly stated or
not, claims include a judgment about the likelihood or probability that what they
are claiming is true, or will become true:
- There is a high probability that Australia will suffer a major terrorist
attack in the next decade. - There is some chance that Australia will suffer a major terrorist attack
in the next decade. - There is virtually no chance that Australia will suffer a major terrorist
attack in the next decade.
In each case, the claims are saying something about Australia and terrorism;
they differ only in their explicit statement of the probability that the substance of
the claim will come true. Understanding how to include proper indications of
scope and certainty in the claims you write, or to recognise them in other people's
work, is crucial to being an effective reasoner. Remember, scope and certainty are
tied in with the idea that claims are asserting the truth of something. If you limit
or qualify your claims by appropriately indicating scope and certainty, then you are
thinking more clearly and therefore can write better claims.
Exercise 2.5
Identify the two components that are internally linked within each of the following
claims. Then rank claims a-c in order of scope (from widest to narrowest) and
claims d-f in order of certainty (from most certain to least certain). In each case
identify the word or words that lead you to your judgment. Then write a list of some
of the other words that can be used to indicate the scope and certainty of a claim.
a. Sometimes, when I drink milk, I feel sick.
b. Whenever I eat cheese before sleeping, I have dreams.
c. Occasionally, after eating rich food, I get indigestion.
d. It is probable that humans will live in space.
e. There is no way that humans can live in outer space.
f. I'd say the odds are 50:50 that humans will live in space.
Descriptive and value claims
Some claims assert that things are, or have been, a certain way; and some claims
make judgments about the way things should or should not be. These are
respectively called descriptive claims and value claims. For example, 'This book is
printed on white paper' describes the type of paper, whereas 'We should use less