Commentary: nobody loves a critic: Edmund A Parkes and John Snow's cholera.

Science isn’t about being right. It is about convincing others of the correctness of an idea through a methodology all will accept using data everyone can trust. New ideas take time to be accepted because they compete with others that already have passed the test. New thinking needs a strongly favoured methodology and an iron-clad application if it is to triumph, replacing the old. Journal critics are the first line of defence against ideas and research projects that seem promising but have yet to be vetted, their methods analysed carefully. Despite the importance of that service, the critic’s role is typically disparaged because—let us be frank here— nobody likes critics. If they praise something they’re assumed to be sycophants and if they disparage published work they’re dismissed as merely grumblers. History is not kind to critics. Its writers typically dismiss where they do not simply ignore those whose careful reviews argue caution in the face of works destined to become, in the future, classics. Think, here, Prince Peter Kropotkin whose naturalist studies focused upon the limits of Charles Darwin’s evolutionary theory and the direction in which research based upon it would be best directed. Only today—more than 130 years later—is the importance of his critique being acknowledged. There are good critics, of course, even great ones. The best are not only prominent in their field but also stylish essayists whose careful insights educate the general and the professional reader alike. Harvard biologist Richard Lewontin is a current example, an essayist who enfolds each review within an erudite recital of the state of the science being discussed. The result leaves the reader (and author) gasping: ‘I wish I had said that.’ As an example of a good critic unfairly dismissed by history think Edmund A Parkes, the British physician and researcher who reviewed John Snow’s famous 1855 opus, On the Mode of Communication of Cholera. In a seven-page, approximately 7800-word essay, Parkes carefully considered and found wanting Snow’s argument that cholera (and plague, and typhoid fever) was solely waterborne. Although the myth of Snow’s brilliance insists his critics were wrong, a careful reading of Parkes’ concerns insists that the myth of Snow is overstated. Yes, cholera is a waterborne disease. But were we to read Snow’s work with attention but without foreknowledge we, too, would find its argument incomplete. This review of the 19th century debate over cholera has more than historical significance. It pits a simplistic, focused explanation against one that was broad and multifactorial. And, too, it demands attention be paid to the researcher’s methodologies and their sufficiency, not just results. Finally, it pits the myth of the lone researcher against the reality of science as a complex, communal, interactive process. In a time of rapidly evolving, epidemic zoonotics, the lessons of that earlier debate are as contemporary as the evolving state of the mutating coronavirus that so concerns us today.