In The Ghost Map, Johnson mentions how even highly respected doctors and other intellectuals were prone to the miasma theory, rarely challenging the notion that cholera was directly caused by the polluted air in a space or the stench of sewage that consumed London. The insistence on this theory was a result of the sway that our olfactory organs have over our body, often inducing involuntary reactions, such as vomiting when smelling rotten food or human excrement; as the terrible odour omnipresent in London was so powerful, it was difficult for inhabitants not to blame it for their sickness. In one way, they were right, as the smell alluded to the lack of waste management that had allowed cholera a comfortable and productive stay. However, what Londoners were ignoring was the purpose of our sense of smell, due to evolution, as identifying warning signs, and not as identifying the root of the problem.
Since the time of cholera, we have evolved in other ways, too. John Snow was initially deterred from his theory about Broad Street water being the source of the cholera spread as it was much clearer and had a less offensive smell than water from other wells – how could it be worse when it looked better? The average modern reader, however, would not be discouraged by the development in his research. Through education, and perhaps the internet, we have accelerated the evolution of our perception of the world around us. It is true that cholera is still invisible to the naked eye, however, we are well-informed about its existence and have such confidence in the science of today, that our belief in it makes it visible to us. In some aspects, it is similar to the faith that religious followers have, where one can believe without physical proof – although it is possible to see microbes with recent contemporary technology, most of us have not.
I would like to draw our attention to the Arabic work “thurrah” (ذَرّة ), which is used in a surah (10:61) in the Quran. “Thurrah” used to be understood as either a type of small ant, or “grain”, or “maize”; in recent translations of the Quran, it is translated as “atom”. The atom had not been discovered when the Quran was written, and the cause of the changing explanations is that it was interpreted as referring to the smallest possible entity. With technological advances, our view of this text has changed in regards to the mental image it creates. It is symbolic of a shift in consciousness.
We have become accustomed to the idea that many of the most powerful forces on Earth are invisible – gravity, the internet, holes in the Ozone layer. Because of this psychological shift in perception, it is not only hard for the reader to imagine Snow’s confusion after comparing water from different wells, but also his understanding of the world and the smallest possible particles.
Most of what we hold to be true – facts about the world we live in – we have never seen with our own eyes. I wonder how our confidence in these “facts” has really altered our psychology and philosophy. Have we become more or less likely to seek out proof for new information – especially with the rise of “fake news” and the current mistrust of media? Do we have more trust in governmental organisations, assuming they know more than us? How have ideas of God or Gods changed with our changing frameworks?
