The Common Sense of Science
Jacob Bronowski’s meditation on the history and philosophy of science
International travel has its benefits. Somewhere between Sydney, Toronto and back again, I found time to read Jacob Bronowski’s The Common Sense of Science. First published in 1951, it’s as profound and relevant today — essential reading for anyone interested in science and science communication (Bronowski would doubtless argue that the two are inseparable).
The book focuses on three key themes in science — order, cause, and chance — introduced during a historical trip from Euclid to Einstein, via Renaissance Europe and the Industrial Revolution.
Science, according to Bronowski, begins with the notion of order — the idea that there are distinct categories of things that share important properties and so can be treated as interchangeable. This ordering is itself an experimental act. It begins with intuitions but these need to be tested:
“It is an experimental activity of trial and error. We must from the outset underline its empirical nature, because there is no test for what is like and what is unlike except an empirical one: that the arrangement of things in these groups chimes and fits with the kind of world, the kind of life which we act out.”
Ordering also depends on the question at hand. We often talk of falsely comparing apples with oranges. Yet Newton’s key insight was that, in the context of gravity, apples and moons may be ordered together.
Newton is also credited with the modern notion of cause, in which the universe is conceived as a machine whose future can, at least in theory, be predicted if its current state is known in sufficient detail:
“Our conception of cause and effect is this: that given a definite configuration of wholly material things, there will always follow upon it the same observable event… As the sun sets, radio reception improves. As we press the switch the light goes on. As the child grows, it becomes able to speak. And if the expected does not happen, if reception does not improve, or the lamp does not light up, or the child persists in gurgling, then we are confident that the configuration from which we started was not the same… The present influences the future and, more, it determines it.”
However, Bronowski points to flaws in this characterisation of cause and effect. The problem is that we cannot fully know the present, even hypothetically, and so our predictions of the future will always carry uncertainty.
This is the third theme — chance — the idea that things are never fully knowable or predictable. The best science can hope for is to reduce uncertainty, to characterise the likelihood of different potential outcomes. It is the most recent of the concepts and the least appreciated, by scientists and non-scientists alike.
“The future does not already exist; it can only be predicted. We must be content to map the places into which it may move and to assign a greater or less likelihood to this or that of its areas of uncertainty.”
Beyond order, cause, and chance, there are other key themes running throughout. Bronowski begins by drawing historical parallels between science and the arts. There was never a “golden age” of the arts that has been somehow supplanted by science. In every great civilization, scientists and artists have “walked together”. Ultimately, science is like any form of human thought or culture. What sets it apart is only its organisation.
The pay-off comes in Chapter 8, when Bronowski finally cements the link between science and literature in perhaps my favourite passage of the book:
“We cannot define truth in science until we move from fact to law. And within the body of laws in turn, what impresses us as truth is the orderly coherence of the pieces. They fit together like the characters in a great novel, or like the words in a poem. Indeed, we should keep that last analogy by us always. For science is a language, and like a language, it defines its parts by the way they make up a meaning. Every word in a sentence has some uncertainty of definition, and yet the sentence defines its own meaning and that of its constituents conclusively. It is the internal unity and coherence of science which gives it truth, and which make it a better system of prediction than any less orderly system” (p136).
The book ends where it began with a defence of science. Bronowski was writing just after the end of World War II and the unleashing of nuclear weapons that owed their existence to Einstein and his famous equation, E = mc². Science stood accused of providing the means of our own destruction.
Bronowski argues that the blame really lies with a society that determines the direction that science takes and provides a context in which science is used to nefarious ends. But he does not absolve scientists entirely:
“They have enjoyed acting the mysterious stranger, the powerful voice without emotion, the expert and the god. They have failed to make themselves comfortable in the talk of people on the street; no one taught them the knack, of course, but they were not keen to learn. And now they find the distance which they enjoyed has turned to distrust, and the awe has turned to fear; and people who are by no means fools really believe that we should be better off without science” (p146).
The Common Sense of Science is now over 65 years old. While some of the language is quite dated and at times pompous, the central message still rings true.
“We know that ours is a remarkable age of science. It is for us to use to broaden and liberate our culture. These are the marks of science: that it is open for all to hear, and all are free to speak their minds in it. They are the marks of the world at its best, and the human spirit at its most challenging” (p153).