Page 170 - Smart Thinking: Skills for Critical Understanding and Writing, 2nd Ed

ANSWERS, DISCUSSION, AND FURTHER ADVICE 157

It would be incorrect to diagram their relationship thus:

Y

Y

Claims 2 and 3 are related and, indeed, are dependent on one another (see
chapter 4). It is wrong to use the [si] symbol for any form of relationship
between claims other than for the logical relationship 'because ... therefore'.
Instead the + symbol should have been used to join claims 2 and 3 on the same
line.
Other incorrect uses of the diagram tend to reflect a misunderstanding of the
fact that, first, the diagramming process must reflect what is written in the text (i.e.
the diagram brings out, explicitly, the relationships between premises and con-
clusions implicit in the wording of those claims); and second, a simple misunder-
standing that the line, arrow, and plus symbols must be used very precisely, to mean
only one thing. Here are examples of technical mistakes in diagramming you need
to avoid:

+

7

M 3