Truth and Falsehood
Arguments are not true or false. Arguments are only good or bad. So the sentences that constitute an argument – the sentence that is asserted, and those sentences on the basis of which the first is asserted – can all be true or false. But the argument itself cannot be true or false.
To say that an argument is true is to say something like ‘that table is loud’. Such a sentence doesn’t really make sense, as anyone who understands ‘table’ and ‘loud’ knows. To say ‘that argument is true’ is to say something equally meaningless.
Similarly, facts, events, and states of affairs are not true or false. It is this sort of thing that makes a sentence, and the belief it expresses, true or false. But this sort of thing is not itself true or false.
For example, the cat’s being on the mat is a state of affairs. Philosophers would say that this state of affairs either obtains or it doesn’t obtain. If it does obtain (if the cat is on the mat) then its obtaining will make the sentence ‘the cat is on the mat’ (and the belief expressed by that sentence) true. If it doesn’t obtain (if the cat isn’t on the mat) then its not obtaining will make the same sentence (and the same belief) false. If it doesn’t obtain, of course, this will make the sentence ‘the cat is not on the mat’ (and the belief expressed by that sentence) true.
Importantly the state of affairs is not itself true or false. The cat’s being on the mat is simply not the sort of thing that can be true or false. Just as someone sincerely attributing loudness to a table manifests his failure to understand ‘table’ and/or ‘loud’, someone who thinks of a state of affairs as true is one who manifests his misunderstanding of what a state of affairs is, and/or what the word ‘true’ means.
Most sentences and beliefs have truth values. They are either true or false. It is a tenet of classical logic that there is no third truth value. According to classical logic there are also no truth value gaps. You will see below, though, that it is only when we use sentences that they have truth values.
Not everyone accepts classical logic. But the critical reasoning you are learning is based on classical logic, so we will accept its tenets. This means accepting bivalence (the belief that when a sentence has a truth value it will be either true or it will be false). We’ll see later that every sentence, when it is being used, has a truth value.
Take a moment to make sure you have understood bivalence. Although we shall be accepting it for the purposes of this book we should recognise that some philosophers reject classical logic because they reject bivalence. Ask yourself whether ‘the dress is red’ is always either true or false, or whether ‘the dress is not not red’ (for example) suggests otherwise.
Taken from Marianne Talbot, chapter one, Critical Reasoning: A Romp Through the Foothills of Logic iBooks (August 2014)