Page 113 - Smart Thinking: Skills for Critical Understanding and Writing, 2nd Ed

100 SMART THINKING: SKILLS FOR CRITICAL UNDERSTANDING & WRITING

(that is, as a list of claims and a diagram). Choose issues that are important to
you and about which you have some knowledge. You will probably find that each
one combines some elements of more than one type.

Review

This chapter has discussed various ways to think about reasoning. You have
learnt about the difference between induction and deduction: the most impor-
tant point to remember from this comparison is that some kinds of reasoning
are about the inherent logic of the way we describe the world in words: that
there are logical relationships built into claims which, necessarily, lead to
other claims. Now this kind of reasoning is not investigative but is the foun-
dation on which inductive reasoning (where you do observe and investigate the
world) is based.
You have also learnt about propositional logic which, again, is all about the
way you can use a claim that proposes how two other claims are related.
Whether or not, in the narrative flow, you actually write a claim in the stan-
dard 'if/then' format doesn't matter: very often, when we reason, we are using
propositions that, if we rewrote them more accurately, would have to be in that
form. Propositional logic is a very important way of finding the links between
apparently disparate events and drawing them together into a conclusion.
You have also considered what I call five types of reasoning. These are not
'types' like induction and deduction—an argument may contain elements of
(say) reasoning from terms, generalisation, and analogy, all through it. But an
argument can only ever be either inductive or deductive. So, these types of
reasoning are presented simply to help open your eyes to the ways in which
you need to think about your reasoning to make it better.
Thus, what we learn by considering those five types of reasoning is that all
argument and explanation starts with a consideration of similarity and differ-
ence; commonality and inconsistency; necessity and sufficiency. These
concepts are an underlying part of chapters 8 and 9, where we look at how to
find information and how to think it through.

CONCEPT CHECK

The following terms and concepts are introduced in this chapter. Before checking
in the Glossary, write a short definition of each term:

analogy, reasoning from
cause, reasoning from
consistency

deduction