7.1 Conditions and conditionals 251
or
[3c] Suppose we did nothing about climate
change, this is what would happen.None of the claims above means that nothing
will be done about climate change. Nor does
it mean that parts of the world will be
submerged in the near future. The only claim
that is being made is that this will happen if
we do (or did) nothing; it is the consequence of
doing nothing.Hypothetical claims
Conditional statements and remarks are
sometimes referred to as ‘hypotheticals’.
‘Hypothetical’, in this context, means
‘conditionally true’. Politicians are often asked
hypothetical questions, particularly by
journalists and media presenters, to try to get
them to commit themselves to some
prediction, or future course of action.
For example:
‘Minister, what will you do if these allegations
of bribery turn out to be true? Will you
resign?’To which the politician is likely to reply:
‘I am not going to answer that question,
because it is purely hypothetical. The
allegations aren’t true.’If she is persistent enough, the journalist may
get the minister to concede:
[4] ‘All right, I would resign if I had taken the
bribe. But I haven’t.’This is not a statement that the minister will
resign, only that he would under certain
conditions. It is thus a hypothetical
statement. Statement [3c] is also hypothetical
in the sense that the speaker is not suggesting
or predicting that nothing will be done.
Indeed the speaker is assuming that
something will be done in view of the
consequences if it is not done.the opposite: it states a score of 70 in the exam is
a sufficient condition but adds that if you get less
you can re-sit. However, you may still have to get
70 or more at some time, so it is unclear whether
the mark of 70 is necessary as well as sufficient.
Possibly on the re-sit the required mark will be
lower, so as to fill any remaining places.
The structure of conditionals
A conditional is a complex statement that is
true or false as a whole, independently of
whether the parts of it are true or not. You
were introduced briefly to complex claims,
including conditionals, in Chapter 2.2. The
example there was the claim that:
[3] Many parts of the world will soon be
submerged if nothing is done to reverse
climate change.This statement consists of two shorter
sentences (or clauses), connected by ‘if’. Note
that the order of the sentences can be reversed,
bringing the if-clause to the front. This is the
standard way to express a conditional in logic.
[3a] If nothing is done about climate change
then many parts of the world will soon
be submerged.The if-clause is called the ‘antecedent’ because
logically it comes before the then-clause. The
then-clause is called the ‘consequent’, because
it follows logically from the antecedent. If the
antecedent is true, then the consequent is true
too. This logical relation holds whether the
conditional is expressed like [3] or [3a]; and
whether or not the word ‘then’ is included.
Conditional claims are extremely valuable
tools for our thinking and reasoning. Without
them we would not be able to reason
hypothetically – that is, without knowing
whether or not the antecedent was true.
Another term for this is suppositional reasoning.
In [3] what the speaker is effectively saying is:
[3b] ‘Suppose we do nothing about climate
change, this is what will happen.’