Question No. 1: In what specific ways was John Snow’s approach to accounting the disease a departure from accepted explanation to the outbreak of cholera?
Prior to John Snow’s approach to accounting for the outbreak of cholera, it was believed by many, including physicians, that the disease was a blood disorder. This was because some of the symptoms of the disease include the bursting of small vessels that make the skin turn blue as the blood become thicker and tar-like because of dehydration. It was also generally believed that the disease was air-borne (Ball 3). The failure then of physicians to pinpoint the nature of the disease prevented the disease from being effectively avoided and cured and from spreading that resulted in epidemics.
John Snow departed from this mindset by pursuing his own theory of the disease. Rather than seeing it as a blood disorder, Snow believed that cholera had something to do with the digestive system and that its spread route is through the fecal-oral system. He was, therefore, looking for the source through which the disease was spread, particularly water source. Rather than examining and interviewing patients, Snow investigated the disease by tracing its origin from the first victim to the last and creating a map that showed the areas and the number of victims in each location ultimately creating a pattern that showed the concentration or clustering of casualties of the disease to a pump in Broad Street. Snow’s approach was unique because he used statistics to imply a connection between the disease and infected water. He was, thus, often called the father of modern epidemiology because his study focused on the causes of the spread of the disease, rather than the disease itself.
Question No. 2: What insight about the nature of cause did his approach embody?
The issue that Snow was trying to solve in his study was to find the reason or the causes of the epidemic. This was very important to stop the disease from further spreading and taking the lives of more people in London during the cholera outbreak in that city in 1831. His approach in solving this particular issue illustrated that an event or incident – in this case, the cause of the epidemic – may be explained by the four natures of causes: matter, form, efficiency, and finality. According to Aristotle, any change in the world results from any of these causes and such a change can be fully threshed out by engaging all of them (Simply Philosophy 2015). The outbreak of cholera in 1831, for example, can be explained by as a chain of events that started with the throwing of the water used in washing the clothes of a child who died of cholera to a cesspool and ended in the cholera outbreak and the death of hundreds in London in 1831.
According to Snow’s investigation, the cholera epidemic of 1831 was caused by the contamination of water that was being pumped out of the water source in Broad Street. In this sense, therefore, the contaminated water in the Broad Street pump was the efficient cause of the cholera epidemic in 1831. By taking a survey of the location of those who died in the epidemic and finding out the source of water used by them, Snow was able to trace back and confine the source of the epidemic – the water in the Broad Street pump. An efficient cause is one that directly results in the effect, but these two are separate events (Johns 54). However, the success of Snow’s investigation was his correct appreciation of the disease – that it was a digestive system disease rather than a blood disorder and thus, water-borne rather than air-borne (Bollet 98). The correctness of this theory led him to pursue the correct investigation path – which was to locate the water source that was causing the epidemic. Peripheral to the efficient and final cause was the material cause of the epidemic, which was the bacterium Vibrio cholerae (Bollet 92) although at that time microbiology was still in infancy and the bacteria was not yet isolated. The formal cause of the epidemic was the throwing of contaminated water to the cesspool, which found its way to the water source in Broad Street and contaminated it.
Question No. 3: What has to be true for something to be considered a cause?
References
Ball, Laura. Cholera and the Pump on Broad Street: The Life and Legacy of John Snow. 2009. Web. 13 July 2015. http://www.ph.ucla.edu/epi/snow/Snow_Laura_Ball.pdf.
Bollet, Alfred Jay. Plagues and Poxes: The Impact of Human History on Epidemic Disease. Demos Health, 2nd ed, 2004. Print.
Jones, Richard. A Theory of Physical Probability. University of Toronto Press, 2002. Print.
Simply Philosophy. The Four Causes. 2015. Web. 12 July 2015. http://simplyphilosophy.org/philosophy/classical-greek-philosophy/aristotle/the-four- causes/.
