فصل 32

chapter 32

Boo!/Hooray!

Alfred Jules Ayer

Wouldn’t it be wonderful if you had a way of knowing when someone was talking nonsense? You’d never need to be fooled again. You could divide everything that you heard or read into statements which made sense and statements which were just nonsense and not worth your time. A.J. Ayer (1910–89) believed he’d discovered one. He called it the Verification Principle.

After spending some months in Austria in the early 1930s attending meetings of a group of brilliant scientists and philosophers known as the Vienna Circle, Ayer returned to Oxford where he was working as a lecturer. At the young age of 24 he wrote a book that declared that most of the history of philosophy was filled with gibberish – it was complete nonsense and more or less worthless. That book, published in 1936, was called Language, Truth and Logic. It was part of a movement known as logical positivism, a movement that celebrated science as the greatest human achievement.

‘Metaphysics’ is a word used to describe the study of any reality that lies beyond our senses, the kind of thing that Kant, Schopenhauer and Hegel believed in. For Ayer, though, ‘metaphysics’ was a dirty word. It was what he was against. Ayer was only interested in what could be known through logic or the senses. But metaphysics often went far beyond either and described realities which couldn’t be investigated scientifically or conceptually. As far as Ayer was concerned, that meant it was of no use at all and should be ditched.

Not surprisingly, Language, Truth and Logic ruffled feathers. Many of the older philosophers in Oxford hated it, which made it difficult for Ayer to get a job. But ruffling feathers is something philosophers have been doing for thousands of years, in the tradition that began with Socrates. Still, to write a book that so openly attacked the work of some of the great philosophers of the past was a brave thing to do.

Ayer’s way of telling meaningful from meaningless sentences was this. Take any sentence, and ask these two questions: (1) Is it true by definition? (2) Is it empirically verifiable?

If it was neither of these then it was meaningless. That was his two-pronged test for meaningfulness. Only statements that were true by definition or empirically verifiable were of any use to philosophers. This needs some explanation. Examples of statements that are true by definition are ‘All ostriches are birds’ or ‘All brothers are male’. These are analytic statements, in Immanuel Kant’s terminology (see Chapter 19). You don’t need to go and investigate ostriches to know they are birds – that’s part of the definition of an ostrich. And obviously you couldn’t have a female brother – no one will ever discover one of those, you can be sure of that; not without a sex change at some point anyway. Statements that are true by definition bring out what is implicit in the terms that we use.

Empirically verifiable statements (‘synthetic’ statements, in Kant’s jargon), in contrast, can give us genuine knowledge. For a statement to be empirically verifiable there has to be some test or observation that will show whether it is true or false. For example if someone says ‘All dolphins eat fish’ we could get some dolphins and offer them fish and see if they eat some. If we discovered a dolphin that never ate fish, then we’d know that the statement was false. That would still be a verifiable statement for Ayer because he used the word ‘verifiable’ to cover both ‘verifiable’ and ‘falsifiable’. Empirically verifiable statements were all factual statements: they are about the way the world is. There must be some observation that will support or undermine them. Science is our best way of examining them.

If the sentence was neither true by definition nor empirically verifiable (or falsifiable), then it was, Ayer declared, meaningless. As simple as that. This bit of Ayer’s philosophy was borrowed straight from David Hume’s work. Hume had half seriously suggested that we should burn works of philosophy that failed this test because they contained nothing but ‘sophistry and illusion’. Ayer reworked Hume’s ideas for the twentieth century.

So, if we take the sentence ‘Some philosophers have beards’ then it is fairly obvious that this isn’t true by definition, since it isn’t part of the definition of a philosopher that some of them must have facial hair. But it is empirically verifiable because it is something we could go out and get evidence about. All we need to do is look at a range of philosophers. If we find some with beards, as we are very likely to do, then we can conclude that the sentence is true. Or, if after looking at many hundreds of philosophers we can’t find a single one with a beard, we may conclude that the sentence ‘Some philosophers have beards’ is probably false, though we can’t be sure without examining every philosopher there is. Either way – true or false – the sentence is meaningful.

Compare that with the sentence ‘My room is full of invisible angels that leave no trace.’ That isn’t true by definition either. But is it empirically verifiable? It seems not. There’s no imaginable way of detecting these invisible angels if they really leave no trace. You can’t touch them or smell them. They don’t leave footprints, and they don’t make a noise. So the sentence is just nonsense, even though it looks as if it might make sense. It is a grammatically correct sentence, but as a statement about the world, it is neither true nor false. It is meaningless.

This can be quite hard to grasp. The sentence ‘My room is full of invisible angels that leave no trace’ seems to mean something. But Ayer’s point is that it contributes nothing whatsoever to human knowledge, though it might sound poetic or could possibly contribute to a work of fiction.

Ayer didn’t just attack metaphysics: ethics and religion were both targets for him too. For example, one of his most challenging conclusions was that moral judgements were literally nonsense. This seemed an outrageous thing to say. But it was what followed if you used his two-pronged test on moral statements. If you say ‘Torture is wrong’ all you are doing, he thought, was the equivalent of saying ‘Torture, boo!’ You are revealing your personal emotions about the issue rather than making a statement that could be true or false. That’s because ‘Torture is wrong’ isn’t true by definition. Nor is it something that we could ever prove or disprove as a fact. There’s no test that you could do that would decide the issue, he believed – something that utilitarians such as Jeremy Bentham and John Stuart Mill would have disputed, since they would have measured the resulting happiness.

It is therefore, on Ayer’s analysis, completely meaningless to say ‘Torture is wrong’ since it is the type of sentence that could never be either true or false. When you say ‘Compassion is good’ all you are doing is showing how you feel: it’s just like saying ‘Compassion, Hooray!’ Not surprisingly, Ayer’s theory of ethics, known as emotivism, is often described as the Boo!/ Hooray! Theory. Some people took Ayer to be saying that morality doesn’t matter, that you can choose to do whatever you like. But that wasn’t his point. He meant that we couldn’t have meaningful discussion of these issues in terms of values, but he did believe that in most debates about what we should do facts were discussed, and these were empirically verifiable.

In another chapter of Language, Truth and Logic Ayer attacked the idea that we could talk meaningfully about God. He argued that the statement ‘God exists’ was neither true nor false; again, it was, he felt, literally meaningless. That’s because it wasn’t true by definition (though some people, following St Anselm, using the Ontological Argument have said God must necessarily exist). And there wasn’t a test you could do to prove God’s existence or non-existence – since he rejected the Design Argument. So Ayer was neither a theist (who believes God exists) nor an atheist (who believes that God doesn’t exist). Rather he thought that ‘God exists’ was just another of those meaningless statements – some people give this position the name ‘igtheism’. So Ayer was an igtheist, that special category of people who think that all talk of God existing or not existing is complete nonsense.

Despite this, Ayer did get a shock very late in life when he had a near-death experience after choking on a bit of salmon bone and falling unconscious. His heart stopped for four minutes.

During that time he had a clear vision of a red light and two ‘Masters of the Universe’ talking to each other. This vision didn’t make him believe in God, far from it, but it did make him question his certainty about whether the mind could continue existing after death.

Unfortunately for Ayer’s logical positivism, it provided the tools for its own destruction. The theory itself didn’t seem to pass its own test. First, it’s not obvious that the theory is true by definition. Secondly, there is no observation that would prove or disprove it. So by its own standards it is meaningless.

For those who turned to philosophy to help them answer questions about how to live, Ayer’s philosophy was of very little use. More promising in many ways was existentialism, the movement that emerged from Europe during and immediately after the Second World War.