Editor’s note: this is a shortened version of a speech that the author was due to give last month at King’s College London which was canceled because the university deemed the event to be too ‘high risk’.
A quick Google search suggests that free speech is a regarded as an important virtue for a functional, enlightened society. For example, according to George Orwell: “If liberty means anything at all, it means the right to tell people what they do not want to hear.” Likewise, Ayaan Hirsi Ali remarked: “Free speech is the bedrock of liberty and a free society, and yes, it includes the right to blaspheme and offend.” In a similar vein, Bill Hicks declared: “Freedom of speech means you support the right of people to say exactly those ideas which you do not agree with”.
But why do we specifically need free speech in science? Surely we just take measurements and publish our data? No chit chat required. We need free speech in science because science is not really about microscopes, or pipettes, or test tubes, or even Large Hadron Colliders. These are merely tools that help us to accomplish a far greater mission, which is to choose between rival narratives, in the vicious, no-holds-barred battle of ideas that we call “science”.
For example, stomach problems such as gastritis and ulcers were historically viewed as the products of stress. This opinion was challenged in the late 1970s by the Australian doctors Robin Warren and Barry Marshall, who suspected that stomach problems were caused by infection with the bacteria Helicobacter pylori. Frustrated by skepticism from the medical establishment and by difficulties publishing his academic papers, in 1984, Barry Marshall appointed himself his own experimental subject and drank a Petri dish full of H. pylori culture. He promptly developed gastritis which was then cured with antibiotics, suggesting that H. pylori has a causal role in this type of illness. You would have thought that given this clear-cut evidence supporting Warren and Marshall’s opinion, their opponents would immediately concede defeat. But scientists are only human and opposition to Warren and Marshall persisted. In the end it was two decades before their crucial work on H. pylori gained the recognition it deserved, with the award of the 2005 Nobel Prize in Physiology or Medicine.
From this episode we can see that even in situations where laboratory experiments can provide clear evidence in favour of a particular scientific opinion, opponents will typically refuse to accept it. Instead scientists tend cling so stubbornly to their pet theories that no amount of evidence will change their minds and only death can bring an end to the argument, as famously observed by Max Planck:
A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.
It is a salutary lesson that even in a society that permits free speech, Warren and Marshall had difficulty publishing their results. If their opponents had the legal power to silence them their breakthrough would have taken even longer to have become clinically accepted and even more people would have suffered unnecessarily with gastric illness that could have been cured quickly and easily with a course of antibiotics. But scientific domains in which a single experiment can provide a definitive answer are rare. For example, Charles Darwin’s principle of evolution by natural selection concerns slow, large-scale processes that are unsuited to testing in a laboratory. In these cases, we take a bird’s eye view of the facts of the matter and attempt to form an opinion about what they mean.
This allows a lot of room for argument, but as long as both sides are able to speak up, we can at least have a debate: when a researcher disagrees with the findings of an opponent’s study, they traditionally write an open letter to the journal editor critiquing the paper in question and setting out their counter-evidence. Their opponent then writes a rebuttal, with both letters being published in the journal with names attached so that the public can weigh up the opinions of the two parties and decide for themselves whose stance they favour. I recently took part in just such an exchange of letters in the elite journal Trends in Cognitive Sciences. The tone is fierce and neither side changed their opinions, but at least there is a debate that the public can observe and evaluate.