MORE EFFECTIVE REASONING II: BETTER LINKS 87necessary claims in the chain. Equally, we must not confuse claims that
support another claim (diagrammed above the claim being supported) with
claims that are dependent (diagrammed alongside one another).
The relationships of premises above with conclusion below are only strong
if the premises are relevant and provide strong support. We judge relevance by
looking at whether or not the premise is connected in some way to the conclu-
sion (through the form of words or the issues involved or via some background
knowledge). To establish relevance, we can include a framing premise if
necessary or write our claims more carefully. Premises provide sufficient
support for a conclusion if, in context, other people will judge the degree of
support to be sufficient. We can ensure effective reasoning only by making
sure that we satisfy any burden of proof we have, attending to the detail of our
conclusion (justifying all aspects of it), making sure there is coherence
between scope and certainty, and reasoning broadly where necessary.CONCEPT CHECK
The following terms and concepts are introduced in this chapter. Before checking
in the Glossary, write a short definition of each term:
breadth of reasoning
burden of proof
depth of reasoning
relevance
strength of support
Review exercise 6
Answer briefly the following questions, giving, where possible, an example in your
answer that is different from those used in this book:
a. How many reasons does a chain of dependent premises offer in support of
a conclusion?
b. What is an implied premise?
c. What is the difference between the relevance and acceptability of a claim?
d. How might a framing premise be used in connection with relevance?
e. What role does the idea of well-founded claims play in relation to
relevance and support?
f. What is the difference between depth and breadth of reasoning?
g. How can we use scope and certainty to judge the effectiveness of
reasoning?