Bronowski on “absolute knowledge”

In this moving clip taken from the very end of his acclaimed TV series The Ascent of Man, Jacob Bronowski speaks of two great human evils.

The first is the idea that “the end justified the means” — or as I would put it: if a particular end is treated as supremely valuable, its pursuit can ride roughshod over the many other competing values that characterise human life.

The second is the idea that we can have “absolute knowledge”. What does Bronowski mean by “absolute knowledge”? To understand this, consider how he defends science against the charge that it dehumanises people. He is standing in front of a dark pond in the grounds of Auschwitz, where the ashes of millions of people were flushed. These people were not victims of science. They were not killed by gas, he says, but by “arrogance”, “dogma” and “ignorance”:

When people believe that they have absolute knowledge, with no test in reality, this [gesturing towards the pool of death] is how they behave. This is what men do when they aspire to the knowledge of gods. Science is a very human form of knowledge. We are always at the brink of the known — we always feel forward for what is to be hoped. Every judgement in science stands on the edge of error and is personal. Science is a tribute to what we can know although we are fallible.

Now Bronowski doesn’t embrace any sort of “postmodernist” nonsense along the lines of “truth is relative”. He uses the words ‘true’ and ‘false’ freely, and clearly thinks they mean the same for everyone. Rather, in denying that we have “absolute knowledge”, his focus is on the traditional “justification” condition on knowledge. (It was traditionally thought that when we know something, we believe it, it is true, and we have a rational assurance or “justification” in believing it.) Bronowski is saying that justification or assurance is never absolute. It isn’t simply that it isn’t total or 100% — we can’t even measure it in an objective way. We can never have an impersonal or numerical assurance of what we believe or ought to believe. Assurance always depends on what each individual already believes, and that always differs from one individual to the next.

Bronowski is a “fallibilist” with respect to knowledge. That is, we are often mistaken, but we can have knowledge despite the ever-present possibility of error. Knowledge is a matter of our beliefs actually being true of the world. It’s an aspiration, a project guided by hope — and it’s often a matter of sheer luck. When we have knowledge, it’s not because our assurance is “absolute”, but because as a matter of fact our hope has paid off, and we have stumbled upon theories that happen to be true. In science, we have to “feel forward” in a tentative, exploratory way by guessing and then testing our theories against reality. The result of such tests is not a numerical measure of “how likely our theories are to be true”, but various hints and suggestions that we are “on to something” — which are bound to strike different individuals in different subjective ways. That’s part of what Bronowski means when he says science is a very “human form of knowledge”.

Nowadays, hardly anyone thinks we can have absolute certainty. Even the Nazis didn’t think that. But there is another “level of assurance”, which Descartes called “moral certainty”. This is not “total assurance”, but “assurance enough” to act so as to achieve some end. If we think assurance is absolute, objective, measurable, or suchlike, then everyone is rationally obliged to act in the same way to achieve the same end. I think that is the Nazi poison that Bronowski has in mind.

I think we should take Bronowski’s warnings seriously, and beware of movements that put one overriding end above all the other human values. And beware of claims that assurance can be objective or numerically measured.

Why would anyone think such a thing? I think such thoughts have two ingredients. The first is ambiguity in words such as ‘likely’ and ‘probable’. In science and statistics these words refer exclusively to relative frequency — that is, to the numerical proportion of members of a class that have some property. Sometimes, when we know practically nothing about a repeated phenomenon, we have to make judgements guided by nothing better than relative frequency. For example, consider gambling with cards, or wondering about Earth-collisions by objects such as comets and asteroids. If the only thing we know about such phenomena is the relative frequency of various hands of poker or of near misses in the long run, that is all we have to guide our behaviour. That’s how casinos make a profit and how governments should make contingency plans for asteroid collisions — and allocate resources for floods. It’s better than nothing, and it’s “objective”, but it’s not a measure of how much assurance we can have in believing anything.

Yet words such as ‘likely’ and ‘probable’ are often used in everyday parlance to refer to a supposedly objective assurance — assurance in believing that an individual event will occur, or that a given theory is true. Talk of numerical relative frequency often slides imperceptibly into talk of assurance.

The second ingredient is a worship of “science” in general — not this or that theory or branch of science, but the entire enterprise as if it were one monolithic body of assured knowledge. With this worship comes uncritical respect for “scientists” — not as practitioners of this or that branch of science, but as miracle workers whose opinions it is downright immoral to disagree with. Nowadays, it’s common to hear people proudly announcing that they “believe the science” — and implicitly shaming those who “refuse” to “believe the science”. That is a terrible state of affairs — and it represents a backward slide of civilisation. A descent rather than ascent.

Science consists of theories about the world. Many of these theories are about very abstract entities that can’t be observed directly. But none of them are about how much assurance we have that any scientific theory is true. Science doesn’t pronounce upon its own belief-worthiness. Anyone who says it does is either a fool or a fraud. That is to treat science as miraculous, and scientists as shamanistic miracle-workers, the purveyors of “absolute knowledge”.

What is “denial”?

When we say someone is “in denial”, we mean that they reject something obvious — something so obvious that their rejection of it amounts to a sort of pathology. For example, in the movie Psycho, Norman Bates interacts with the skeletal remains of his obviously dead mother as if she were still alive. This is not a sign of good mental health.

Although “deniers” deny facts, they usually do so for “emotional” reasons. They want something to be true so much that they pretend that some other things are false. Dolly Parton uses this idea effectively in The Grass is Blue:

There’s snow in the tropics
There’s ice on the sun
It’s hot in the Arctic
And crying is fun
And I’m happy now
And I’m so glad we’re through
And the sky is all green
And the grass is all blue

It’s vital to see that denial is not the mere rejection of facts — it’s the rejection of obvious facts, things that almost everyone can see easily with their own eyes.

We might say that denial is rejection of “observational” facts rather than “theoretical” facts. Fine, but all observation is “theory laden” — in other words, observations have to be interpreted, there’s no such thing as “raw data”, there’s no sharp distinction between observation and theory, and so on.

There is a gradient here, between facts that can be directly checked by simply opening our eyes and looking, and facts that are more abstract — facts that leave more room for doubt, that can be interpreted in several different ways, that depend on theoretical commitments that are not universally shared.

Some facts lie near enough to the observational end of the gradient to be counted as “almost observational” themselves. For example, we can’t quite see directly that the Earth is round. But nowadays we’re familiar with photographs taken from space of a round Earth, and most of us have watched ships slowly disappearing over the horizon, and so on. When we fly long distances, we adjust our watches in the perfectly reliable expectation that we will land in a different sector on the surface of a rotating sphere. Nowadays, a person who insists the Earth is not round is denying something very close to “obvious”.

Words like ‘denial’ can serve a useful purpose. But they are abused when applied to the rejection of claims that are not obvious. In that situation, their use amounts to an appeal to authority rather than an appeal to observation. The theoreticians whose opinions are rejected are supposedly so authoritative that it takes a sort of mental pathology to disagree with them.

I can’t think of a less sceptical or less scientific attitude than one that demands obedience to the authorities by “taking their word for it”. Heretics were tortured and killed by people who justified their sadism by saying their victims were suffering from a sort of pathology — one whose “cure” need not involve the giving of reasons.

Sometimes I have to restrain myself from using words like ‘denial’ for Creationists who reject the theory of evolution. But then I remind myself that the theory of evolution isn’t obvious — if it were, it wouldn’t have taken someone of Darwin’s stature to provide a satisfactory account of it. People who reject evolutionary theory are sceptical about something I believe in, but they can’t reasonably be called “deniers”. This also applies to other types of scepticism.