Thinking Skills: Critical Thinking and Problem Solving

2.10 Flaws and fallacies 73

Commentary

We will take the options one at a time. A does

not expose any flaw in the argument because if

it does anything at all it supports the argument.

It appears to sympathise with the conclusion

that people should trust their own judgement.

B looks much more of a challenge than A

did. But challenging an argument is not the

There is another way of identifying an error

of reasoning which does not describe the flaw

directly, but reveals or exposes it – shows it

up. It may be a counter-argument, an example

or explanation, or even a question.

Reasons

Conclusion

A useful metaphor for an argument is a see-saw,
or balance arm, with reasons on one side and
the conclusion on the other. If the conclusion
is too strong, or asserts too much, the reasons
may not have sufficient ‘weight’ to support it.
For an argument to be sound the reasons must
outweigh the conclusion. In [5] they don’t
even counter-balance it. They are insufficient.

Identifying flaws
It is one thing being able to see that an
argument is flawed. It is another being able to
say what the flaw is. It is not enough just to
say that the reasons are insufficient or
inadequate, or that the conclusion doesn’t
follow from the reasons, because that is the
same as saying the argument is fallacious. We
need a deeper explanation.
In this unit you have seen two very
common reasoning errors. One was taking a
particular point (e.g. about one person’s
business experience) and drawing a general
conclusion from it (e.g. about how to start up
any business), as in argument [1]. Another,
illustrated in argument [5], involved using
past experience to draw an unwarranted
conclusion about the future.
Thus, if you were asked to describe the kind
of flaw that weakens [5] you could answer:

It assumes that what has been true in the

past remains true now, or in the future.

Or, with more specific reference to [5]:

It assumes that because people have walked

on the ice safely in February in the past, it is

always safe to do so.

Either of these would be a correct answer.

Recall the argument at the start of the

chapter:

The outstanding success of Amulk’s

company, which was launched against

the advice and without the support of

bankers, business consultants and

financiers, just goes to show that one

person’s vision can prove all the experts

in the world wrong. Anyone thinking of

setting up in business should therefore

trust their own judgement, and not be

influenced by the advice of others.

Discuss each of the following responses to

this argument. Do any of them put a finger on

the flaw in the reasoning?

A Many people may have been put off

starting their own businesses because

they paid too much attention to the

advice of so-called experts.

B Business consultants and financiers

know far more about setting up in

business than the man in the street

knows.

C Might Amulk just have been lucky, or

the ‘experts’ to whom he spoke not

so expert?

Activity