The Demon-Haunted World_ Science as a Candle in the Dark - Carl Sagan [124]
These histories have traditionally been written by admired academic historians, often pillars of the establishment. Local dissent is given short shrift. Objectivity is sacrificed in the service of higher goals. From this doleful fact, some have gone so far as to conclude that there is no such thing as history, no possibility of reconstructing the actual events; that all we have are biased self-justifications; and that this conclusion stretches from history to all of knowledge, science included.
And yet who would deny that there were actual sequences of historical events, with real causal threads, even if our ability to reconstruct them in their full weave is limited, even if the signal is awash in an ocean of self-congratulatory noise? The danger of subjectivity and prejudice has been apparent from the beginning of history. Thucydides warned against it. Cicero wrote
The first law is that the historian shall never dare to set down what is false; the second, that he shall never dare to conceal the truth; the third, that there shall be no suspicion in his work of either favouritism or prejudice.
Lucian of Samosata, in How History Should Be Written, published in the year 170, urged “The historian should be fearless and incorruptible; a man of independence, loving frankness and truth’.
It is the responsibility of those historians with integrity to try to reconstruct that actual sequence of events, however disappointing or alarming it may be. Historians learn to suppress their natural indignation about affronts to their nations and acknowledge, where appropriate, that their national leaders may have committed atrocious crimes. They may have to dodge outraged patriots as an occupational hazard. They recognize that accounts of events have passed through biased human filters, and that historians themselves have biases. Those who want to know what actually happened will become fully conversant with the views of historians in other, once adversary, nations. All that can be hoped for is a set of successive approximations: by slow steps, and through improving self-knowledge, our understanding of historical events improves.
Something similar is true in science. We have biases; we breathe in the prevailing prejudices from our surroundings like everyone else. Scientists have on occasion given aid and comfort to a variety of noxious doctrines (including the supposed ‘superiority’ of one ethnic group or gender over another from measurements of brain size or skull bumps or IQ tests). Scientists are often reluctant to offend the rich and powerful. Occasionally, a few of them cheat and steal. Some worked - many without a trace of moral regret -for the Nazis. Scientists also exhibit biases connected with human chauvinisms and with our intellectual limitations. As I’ve discussed earlier, scientists are also responsible for deadly technologies - sometimes inventing them on purpose, sometimes being insufficiently cautious about unintended side-effects. But it is also scientists who, in most such cases, have blown the whistle alerting us to the danger.
Scientists make mistakes. Accordingly, it is the job of the scientist to recognize our weakness, to examine the widest range of opinions, to be ruthlessly self-critical. Science is a collective enterprise with the error-correction machinery often running smoothly. It has an overwhelming advantage over history, because in science we can do experiments. If you are unsure of the negotiations leading to the Treaty of Paris in 1814-15, replaying the events is an unavailable option. You can only dig into old records. You cannot even ask questions of the participants. Every one of them is dead.
But for many questions in science, you can rerun the event as many times as you like, examine it in new ways, test a wide range of alternative hypotheses. When new tools are devised, you can perform the experiment again and see what emerges