Critical Thinking

Vagueness & Ambiguity

Whether or not we accept a piece of reasoning will often depend upon how clearly we understand the terms involved.

This is often unproblematic, but there will be times when clarification is called for.

Many of the words and expressions we use on a daily basis are vague, but their meaning is fixed by context.

But whilst vagueness and ambiguity may be unproblematic features of everyday language, the same does not hold true of arguments.

To be effective, arguments require a much greater degree of clarity and precision than is to be found in everyday discourse. This is where the notion of clarifying terms comes in.

Vagueness

An expression is vague if its meaning is not fixed or clear. An expression is precise if it is.

Example: ‘He is tall’= vague (how tall?)
‘He is 6’5”’ = precise

Some expressions are naturally vague. The example often cited is that of a ‘heap’. Few would argue that two or three grains of sand could be called a heap or that a thousand grains of sand could not. But at what point, during the process of adding grains of sand together, does a ‘heap’ emerge…?

Ambiguity

A word or expression is ambiguous if it has more than one meaning.

Typing the word ‘critical’ into the Microsoft Thesaurus, for example, reveals that the word can mean ‘dangerous’, ‘significant’, ‘unfavourable’ or ‘life threatening’! When used within the context of ‘critical thinking’, needless to say, it tends to mean ‘logical’ or ‘analytic’.

Whenever there is any doubt, we always need to be clear about which meaning of a word is intended and the best guide here is usually context:

The building is in a critical state of repair.
It is critical you understand this.
Why do you always have to be so critical?
He’s still in a critical condition.

But it is not just words that can be ambiguous, sentences can be too. Here are some examples of genuine headlines taken from local and national newspapers (funwithwords.com) all of which contain ambiguities:

It should be clear that each can be read in one of two ways! Fortunately, it is often the most obvious way that is the correct one.

When analysing a piece of reasoning that contains ambiguity, you will need to:

a) identify the ambiguous term/s involved

b) explain the different ways in which these can be understood and

c) come to a decision (based on context or additional information) about which of these is the correct one.

Where no such decision can be made (i.e. when the context of the claim doesn’t fix its meaning) judgement should be suspended.