This chapter examines the ideas of C. P. Snow (The Two Cultures), Richard Dawkins (genetic determinism), Craig Venter (‘creating’ life) and Denis Noble (principle of biological relativity). The theory of biological relativity says there is no hierarchy in biological systems and no level in its organisation that has precedence over any other level. This denial of a hierarchy is the denial of determinism, including, in particular, genetic determinism. From the perspective of the modern plagues, the principle insists that there is no single solution available to ending those plagues.

Concurrent with the top-down change already described, the Health Society requires bottom-up change in every community. Such change is required because the modern plagues spread through social networks that operate predominantly at the community level. The authors propose that the starting point for this change is through reconfiguring the NHS Health Check. Reconfiguration includes the introduction of Health Society professionals and Health Society Champions. Evaluation of the development of the Health Society should include a target for improved healthspan. Because this is an exercise in experimental epidemiology (not merely in today’s convention of observational epidemiology), a pilot Health Society should be tested. Suitable locations for this pilot (including Greater Manchester) are identified.

The case is made that the high prevalence of common long-term conditions justifies describing them as modern plagues. The symptoms of the principal conditions are described. These conditions are considered in the context of their impact on curtailing healthspan - the age at which people cometo the end of their fully healthy lives. While medical healthcare has extended lifespan, the curtailment of healthspan results in years or decades of disability. This gap between healthspan and lifespan diminishes as deprivation declines.

While some risks for disease like our genetic make-up cannot be modified, many risks are amenable to reduction. The major modifiable risk factors for the modern plagues are outlined: our body mass index and obesity; our levels of physical activity; and degrees of social isolation. While infections spread through a population owing to the transmission of a physical disease agent, research shows that modifiable risk factors like obesity spread via social networks. These modifiable risk factors all arise from modern ways of life. This term is preferred to ‘lifestyle’ which implies that way of life is a matter of individual choice. This chapter looks at the definition of obesity, its prevalence and its transmission through social networks. It considers historical change in the prevalence of physical activity and recommendations on optimal levels of such activity, the rise of social isolation, and the risks that arise from the current modern way of life.

Diagnosis of one of the modern plagues is simply the beginning of the accumulation of disabilities at the end of healthspan. Other long-term conditions – including more than one modern plague - tend to arise after the diagnosis of the first one. Individuals must endure successively increasing numbers of long-term conditions. Diabetes is associated with increased risk of heart disease and damage to nerves, kidneys, eyes and feet. Conversely, smoking, alcohol and pollution are among the risk factors for the modern plagues.