Philosophers talk a big game when it comes to questioning things. They tell us that philosophy is a place where nothing is settled and everything is up for grabs. They like to think of themselves as the stubborn child all-grown-up, still asking ‘Why? Why? Why?’, long after the parents have thrown in the towel. The cardinal sin is the assumption unexamined, the question unasked. So they keep asking and asking, spurred on by the hope that one day they’ll uncover the truth. Truth has been the goal ever since the beginning.

“‘Then who are the true philosophers?’, he asked. ‘Those whose passion is to see the truth.’” 
– Plato, The Republic

“Rather than love, than money, than fame, give me truth.” 
– Henry David Thoreau, Walden

“To love truth for truth's sake is the principal part of human perfection in this world, and the seed-plot of all other virtues.” 
– John Locke, Letter to Anthony Collins

 “Plato is my friend, Aristotle is my friend, but my greatest friend is truth.” 
– Isaac Newton, Certain Philosophical Questions

(Isaac Newton, formerly known as Formulator of All Three Laws of Motion, Discoverer of the Law of Universal Gravitation and Co-Inventor of Calculus, henceforth to be referred to as Biggest Nerd of All Time, Nominee for Corniest Sentence Ever Written in the English Language. Honestly if I was back there with Newton I would’ve hit him with the old Inbetweeners shtick: Plato-friend! Aristotle-friend! Truth-friend! Truth-friend!)

But it’s not just philosophers and scientists who are concerned with truth. We all want to know what’s true, and we all refer to truth on a daily basis. We say things like, ‘That’s true,’ ‘To tell you the truth’, and sometimes just ‘Truuuuuuuuuuuu.’

This is a good song with a great Kanye feature. I spend the first two minutes just looking forward to that moment when the horns drop off and you get the bells that could sound Christmassy in another context but here the mood is foreboding enough to let you know they’re death knells.

But forget about that video. If you only have two and a half minutes watch this one. Fresh off the back of the ’05 Grammys speech, we’re back again this week serving up more goosebump-inducing Kanye appearances. (FAIR WARNING: this video gets loud.)

Obviously Maxine has totally lost it but, to be fair to her, can you imagine going to a high school open mic, seeing Vic Mensa show up and recomposing yourself after that only to have literal-Kanye-West-in-the-flesh perform right in front of you? Have some empathy, folks.

As far as truth goes, we need to think about two inter-related questions: (1) What is truth? and (2) Why is truth important?

The first question has been asked throughout human history because, not only is it an interesting philosophical problem, it’s also a helpful distraction tactic. Say you find yourself in a sticky situation – perhaps you’re being pressured into crucifying the Son of God or you’ve been accused of making an idiot the most powerful man on earth – you can ask ‘What is truth?’ and then (hopefully) escape unharmed amidst the ensuing confusion. Who says philosophy can’t be practical?

John 18

Can't be a hotbed of fake news if nothing is real or fake. *Mark Zuckerberg presses index finger against temple* 

The second question has not been asked so often. In fact, it’s unique insofar as it’s a philosophical question more likely to be asked by non-philosophers. Most philosophers (and scientists) think the answer is obvious. They say truth is important simply because it’s true. I think this is a mistake and I’m going to address it in a future post. For now, though, we’re going to stick with this:

What is truth?

There are four main theories of truth: the correspondence theory, the coherence theory, the pragmatic theory and the deflationary theory. The first three all share a common assumption: that truth is a real property. The deflationary theory denies this, saying that there's really nothing there. For the deflationist, saying ''grass is green' is true' is exactly the same as just saying 'grass is green.' Because of this major difference, I'm going to save discussion of the deflationary theory for a later date. In this post, I only discuss the correspondence theory, the coherence theory and the pragmatic theory. I’m going to give a quick run-down of all three before we get to deciding which, if any, is best.

First off, the correspondence theory. This is the Hooke’s law of truth-theories. You remember Hooke’s law from GCSE physics? F=kX AKA stretchy-things stretch further when you pull them harder AKA no shit bozo. It’s criminal to me that you can get your name etched in the history books with a theory this obvious.

The correspondence theory of truth is named after no-one in particular because any old chump could’ve thought it up. But it took the genius of Aristotle to turn it into a tongue-twister:

"To say that that which is, is not, and that which is not, is, is a falsehood; therefore, to say that which is, is, and that which is not, is not, is true."
– Aristotle, Metaphysics

The idea here is that a proposition is true if it corresponds to reality. The proposition ‘Lemons are yellow’ is true if lemons are yellow in reality, and it’s false if they’re not. Truth, the correspondence theorist says, is a relationship between what we say and what’s really out there.

Coherence theorists say something different. They say that truth is a relationship purely between the things we say. A proposition is true if it coheres (that is, fits well) with our beliefs. This idea chimes nicely with the way we often determine truth in day-to-day life. Say, for instance, that you’re checking your email and come across the following proposition:

(A) ‘Congratulations! You’ve won a car.’

You need to determine if this proposition is true, so you think about some other propositions you already think are true.

(1)   Cars are expensive.
(2)   People do not normally give expensive things away for free.
(3)   I haven’t entered any competitions to win a car.
(4)   Email scams involving false promises are common.

(A) does not fit well with the other propositions. So, the coherence theorist will say, (A) is probably false. The proposition that coheres better is the opposite – you have not won a car – and so that’s the one that’s probably true.

Finally, we have pragmatic theories. A nineteenth-century American philosopher called William James sums up these theories best:

“An idea is ‘true’ so long as to believe it is profitable to our lives.”
– William James, Pragmatism

Truth, for James, isn’t about correspondence to reality or coherence with the rest of our beliefs. In fact, a true proposition can be neither of these things as long as it helps make our lives go better.

Say you’re in a job interview and you’re trying to determine the truth of the following proposition:

(B) ‘I will get this job.’

Now you know that nine other people are applying for the job and they’re all similarly qualified, so you’ve got a roughly 10% chance. In light of this small chance, the correspondence and coherence theories will say that (B) is probably false.

But this isn’t a very useful belief to have. You’re shaking! And you’re sweating! You spent £34 on this train ticket and it’s probably going to come to nothing! Why are you even here! You could be in bed right now eating Jaffa Cakes!

It’d be more useful to you if (B) was true. If you believed you were going to get the job, you could calm down. You could project the air of cool confidence and nonchalance that’s like catnip for hiring managers with little else to go on. Your life would go better if (B) was true. So, the pragmatists say, that means it is true! It’s true! You’ll get the job!

The pragmatic theory of truth is liable to strike people as straight-up silly. They'll say you can't just believe anything you want and call it true! But William James would agree with this. I chose the job interview example to make clear how the pragmatic theory differs to the correspondence and coherence theories. In 99% of cases, the pragmatic theory will agree with the other theories about what's true. In 99% of cases, the most useful belief to have is the one that corresponds with reality. Take the following proposition, for instance:

(C) 'My train leaves at 8:02.'

This belief will only make your life better if the train really does leave at 8:02. After all, you don't want to miss it! The pragmatic theory and the correspondence theory both agree that it's true.

Thus concludes our quick run-down of truth-theories. How do we criticise them?

This is much more difficult than it seems. A bad theory is a theory that isn’t true, but how do we decide whether a theory of truth is true? We haven’t yet decided what truth is! We’re trapped in a circle. We need to know what truth is in order to choose a theory of truth, but we need a theory of truth in order to know what truth is! This is like driving on a roundabout with no exits. No matter how far we go, we’re not going to get anywhere.

We can’t use the concepts of truth or falsity, then, to criticise theories of truth. We’ll have to draw on some other ones. As I see it, there are three criteria we can refer to:
  1. Consistency
  2. Simplicity
  3. Intuition
1. Consistency

The first is consistency. There’s no single idea of truth that we can use to judge all three of our theories but we can use each theory’s idea of truth against it. If a theory’s own idea of truth makes the theory false, then it’s self-defeating.

Unfortunately this principle doesn’t really help us. Does the correspondence theory of truth correspond to reality? Eh, difficult to say. It’s hard to know what it’s even supposed to correspond to. Does the coherence theory cohere with our other beliefs? Depends what those other beliefs are. Does believing the pragmatic theory make our lives go better? Who knows.

So none of the theories are obviously self-defeating. At this point, all three of our theories are still in the game.

2. Simplicity

Ah, Ockham’s Razor. We meet again. But, again, old Ockham can’t help us here. All of the theories are quite modest as far as positing entities goes. Maybe you could make the case that the correspondence theory posits two entities (propositions and reality) and the pragmatic theory posits two entities (propositions and lives) whilst the coherence theory only posits one (propositions), but you’d have to be pretty bold to call reality and lives unnecessary entities. Once again, Ockham has left us like a woman in a razor advert: having fun but shaving precisely nothing.

3. Intuition

In philosophy, as in everything else, you sometimes just have to go with your gut. Philosophers try to make this method of deciding sound more respectable by calling it appealing to intuition but they’re basically working by the same principle as these guys: when it [feels] right, it’s [probably] right.

If your intuition isn’t swinging you any particular way already, consider this law:

The Law of Non-Contradiction: No proposition can be true and false at the same time.

Most people intuitively accept this law. It seems impossible for a sentence to be both true and false. We can use this law to rule out two of our theories of truth.

The first is the coherence theory. Imagine I believe that global warming is a myth and you believe that global warming is real. Now consider the following proposition:

(D) ‘The average global temperature will rise by over 1℃ in the next fifty years.’

Proposition D doesn’t cohere with my beliefs, so the coherence theorist will say that, for me, proposition D is false. But it does cohere with your beliefs, so for you, D is true. The coherence theorist has to say that D is both true and false, meaning they fall foul of the law of non-contradiction.

Coherence theorists can avoid this consequence by changing their theory slightly. Instead of saying that true propositions must cohere with the rest of your beliefs, they can say that true propositions must cohere with the beliefs of the majority of people. Truth then becomes a democratic matter. If more people believe in global warming, then it’s true that the earth is warming up. If more people believe it’s a myth, then it’s not true.

But this version of coherence theory is unlikely to pass the gut-check. It seems crazy to say that we can discover what’s true just by taking a poll of what people believe. Accepting this would mean having to say it’s true that 93% of people are above-average drivers and Brexit is truly a good idea.

The law of non-contradiction also thwarts the pragmatic theory. Imagine I’m in a job interview and you’re the person interviewing me. Now consider the following proposition:

(E) ‘Elliott Thornley will get this job.’

Proposition E is useful for me to believe. It’ll help me calm down and impress you. But E might not be useful for you to believe. It might lead you to select me even though I'm not the best candidate, in which case your business is likely to suffer. In that case, the pragmatist must say that E is true for me and false for you, again falling foul of the law of non-contradiction. The pragmatic theory doesn’t pass the gut-test.

The correspondence theory is the only one left standing, and this one abides by the law of non-contradiction. ‘There’s a cat on the top of the Eiffel Tower’ can’t be true and false at the same time. Either there’s a cat there or there isn’t.

The correspondence theory also satisfies our intuitions more generally. It fits best with the way we use the word ‘true’ in day-to-day life. If someone tells you ‘The world’s oldest clam was 507 years old and was killed by scientists trying to determine its age!’, you might say ‘No way!’, and they’d say ‘It’s true!’. Then if you asked ‘What do you mean?’, they wouldn’t say ‘It coheres with my other beliefs!’ or ‘It’s useful for me to believe!’. They’d say ‘It really happened! The clam really was 507 years old and the scientists really did kill it!’ When we talk about truth, we are almost always talking about correspondence.

This conclusion is quite disappointing for philosophers. It just seems a bit too easy. If you’re disappointed, you can take comfort in the fact that the correspondence theory laid out here is still very vague. It tells us nothing about how we can know our propositions correspond to reality and it gives no reason for thinking truth is especially important. There will be plenty of difficulty yet.

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