Excerpt from my new book: Critical Reasoning: A Romp Through the Foothills of Logic

Truth and Falsehood

Critical Reasoning: A Romp Through the Foothills of Logic by Marianne Talbot

Critical Reasoning: A Romp Through the Foothills of Logic by Marianne Talbot

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.

Cat on mat

Cat on mat

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.

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Red Dress

Red Dress

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.

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Taken from Marianne Talbot, chapter one, Critical Reasoning: A Romp Through the Foothills of Logic iBooks (August 2014)

About Marianne

Marianne is Director of Studies in Philosophy at Oxford University's Department for Continuing Education
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8 Responses to Excerpt from my new book: Critical Reasoning: A Romp Through the Foothills of Logic

  1. pand0ra@btinternet.com says:

    Soooo…the theory of evolution is not true, but the statement ‘the theory of evolution is true’ may be. Spooky

    • Marianne says:

      Hi Pandora, No theories can be true (mainly because they are constituted of relationally related sentences/beliefs). It is arguments that cannot be true. The theory of evolution is not itself an argument, though it generates lots of arguments.

      But actually your question is very interesting, mainly because it forces us to ask what a theory is.

      • David Lilley says:

        Dear Marianne,

        Happy new year. I’m sure that we may have many conversations this year if, and only if, one of us bows to the best argument and we both “go forward”. I am of the view, to immediately be terminated by a better argument, that there is only argument. There is only argument in evolution, science and parliament. New knowledge of laws of nature and new moral laws come from only one source, argument. I have been a critic of the big headedness of evolution for many years. Its not big, its only history, and we all know that history is “bunk”. If you want to do something you have today and tomorrow. You cannot do it yesterday. But “we are a product of history”. No we are ruled by the best argument and things were different then. “We should learn the lessons of history so that we don’t make the same mistakes again”. No, things were different then, and we should always choose our moral rules based on the best argument and never give this up to “is statements” be they scientific, historic or religious. History is knowledge about “stuff” and we can get stuff on a “need to know basis” with a few taps on our smartphone. Please restrict your learning to concepts and skills. The greatest skill you can learn is the three “R”s, reading, writing and reckoning. It is so sad that so many years after the introduction of the three “R”s, in 1838, 3% of 16 year olds leave school unable to read and write and this is never reported by the media despite £66,000 being spent on their education.

        Evolution may have been an alternative theory 150 years ago but it was never more than history and Richard Dawkins has recently agreed that it is only a fact, history. And to repeat myself, history is bunk.

        I may be wrong but I LOVE TO ARGUE and I would welcome an antithesis.

  2. Terry says:

    Fascinating! It seems that what classical logic considers to be the truth is something outside of direct experience, which I think I would agree with. Language is used to describe what obtains in experience, which is the main point about making an argument. Looking forward to reading more!

  3. Allan Popa says:

    So both Copernicus and the Ptolemaics were dead wrong: neither the earth nor the sun were at the center of the universe.

  4. David Lilley says:

    Marianne. I didn’t follow this. With Tarski, an argument, hypothesis, guess, description, sentence, theory, statement…..is true if it “corresponds with the facts”. There are three kinds of knowledge; belief, opinion (subjective knowledge) and objective knowledge. No there aren’t. Who gives a monkeys what someone believes or their opinion? Some psychologists and sociologist may have an interest. But epistemology/philosophy is only interested in objective knowledge. We get objective knowledge about the world of things and values by P1, TS, EE, P2 repeat (Popper). Mankind grows his knowledge of the world of things and values, cosmology and right and wrong starting with a problem (P1), coming up with a tentative solution (TS), testing the TS, getting a better idea of the problem (P2) and a better idea of what the solution may be followed by repeat, repeat. Put simply, we grow our knowledge by trial and error. And when we have a good answer to the problem we publish and seek independent third party criticism or peer review. If our argument passes independent critical testing it increases its “truth-likeness” and can be put on the shelf marked “objective knowledge”, “truth” or what Popper called World 3. But whilst it may be our best explanation today it may be superseded tomorrow by a new theory having greater explanatory power, universality and “truth-likeness”.

    Whist epistemology is foremost concerned with the growth of knowledge, the scientific method, P1, TS, EE, P2 repeat, and how can we get to know what we might know in decades in years we also have to be concerned with rebuking pseudo-science. We can only tolerate ONE. There is only ONE world and only ONE truth (correspondence with the facts). We cannot have competing economic theories, political theories and psychological theories. We have to use our “epistemological arsenal” which includes rational argument, logic (which includes maths), nominalism (never ask “what is?” questions) and the demarcation criteria (falsifiability) to dismiss pseudo-sciences such as psychoanalysis, Marxism, anarchism, scientific socialism, historicism, chartists, Keynesianism, faiths…

    All disciplines, and epistemology is the king of disciplines, have one golden rule. They “stand on the shoulders of giants and see further”. Why has the king gone to sleep for decades?

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