Background and aim With the increasing interest in lifestyle, health and consequences of unhealthy lifestyles for the healthcare system, a new kind of solidarity is gaining importance: lifestyle solidarity. While it might not seem fair to let other people pay for the costs arising from an unhealthy lifestyle, it does not seem fair either to punish people for their lifestyle. However, it is not clear how solidarity is assessed by people, when considering disease risks or lifestyle risks. The aim of (...) this study was to investigate the degree of solidarity with lifestyle as well as with other factors that are related to health outcomes—for example, old age—and the relation between this degree of solidarity and various characteristics. Methods This cross-sectional study is part of the Dutch longitudinal SMILE study. Data on the degree of solidarity with different lifestyles and old age, and the relation between the degree of solidarity and various demographic and other variables were obtained in a questionnaire survey. Results Solidarity with smokers and overweight people was moderate, as was solidarity with older people. Respondents were ambivalent about athletes. Respondents who were younger, male and highly educated, and those with a healthy lifestyle, a small social network, high quality of life and an internal locus of control, showed low solidarity. Conclusions Solidarity with an unhealthy lifestyle and old age is moderate and the degree of solidarity varies among the different subgroups. (shrink)

Let the individuals of a population be divided into two groups with different personal habits. The core group is associated with health risk behaviors; the non-core group avoids unhealthy activities. Assume that the infected individuals of the core group can spread a contagious disease to the whole population. Also, assume that cure does not confer immunity. Here, an epidemiological model written as a set of ordinary differential equations is proposed to investigate the infection propagation in this population. In the model, (...) migrations between these two groups are allowed; however, the transitions from the non-core group into the core group prevail. These migrations can be either spontaneous or stimulated by social pressure. It is analytically shown that, in the scenario of spontaneous migration, the disease is either naturally eradicated or chronically persists at a constant level. In the scenario of stimulated migration, in addition to eradication and constant persistence, self-sustained oscillations in the number of sick individuals can also be found. These analytical results are illustrated by numerical simulations and discussed from a public health perspective. (shrink)

Open peer commentary on the article “The Circular Conditions of Second-order Science Sporadically Illustrated with Agent-based Experiments at the Roots of Observation” by Manfred Füllsack. Upshot: The aim of my commentary is to reflect on fundamental issues related to circularity, distinction and the properties of observers.

Context: The question of how to understand the epistemology of set theory has been a longstanding problem in the foundations of mathematics since Cantor formulated the theory in the 19th century, and particularly since Bertrand Russell articulated his paradox in the early twentieth century. The theory of types pioneered by Russell and Whitehead was simplified by mathematicians to a single distinction between sets and classes. The question of the meaning of this distinction and its necessity still remains open. Problem: I (...) am concerned with the meaning of the set/class distinction and I wish to show that it arises naturally due to the nature of the sort of distinctions that sets create. Method: The method of the paper is to discuss first the Russell paradox and the arguments of Cantor that preceded it. Then we point out that the Russell set of all sets that are not members of themselves can be replaced by the Russell operator R, which is applied to a set S to form R(S), the set of all sets in S that are not members of themselves. Results: The key point about R(S) is that it is well-defined in terms of S, and R(S) cannot be a member of S. Thus any set, even the simplest one, is incomplete. This provides the solution to the problem that I have posed. It shows that the distinction between sets and classes is natural and necessary. Implications: While we have shown that the distinction between sets and classes is natural and necessary, this can only be the beginning from the point of view of epistemology. It is we who will create further distinctions. And it is up to us to maintain these distinctions, or to allow them to coalesce. Constructivist content: I argue in favor of a constructivist perspective for set theory, mathematics, and the way these structures fit into our natural language and constructed speech and worlds. That is the point of this paper. It is only in the reach for absolutes, ignoring the fact that we are the authors of these structures, that the paradoxes arise. (shrink)

Upshot: Eigenform is a precondition for distinction and distinction is a precondition for eigenform. While my target article discussed eigenform and reflexivity, it could just as well have discussed distinctions and the emergence of distinctions. This theme was implicit in many of the comments. We make this circularity explicit for the sake of a deeper understanding.

Currently living people cannot be said to be wronged because of the wrongless emissons of greenhouse gases by past people. According to the usual subjunctive-historical understanding of harm, currently living people cannot be said to be harmed by the impact of greenhouse emissions on their well-being. By relying on a subjunctive-threshold notion of harm we can justify conclusions about both the present generation’s duties not to violate the rights of future generations, and the present generation’s duties to compensate currently living (...) people for the harms inflicted upon them through the lasting impact of wrongless past harms. This interpretation supports a forward-looking understanding of the grounds of our relating to wrongless past harms. The significance of past harms lies in their consequences for the well-being of currently living and future people. The subjunctive-threshold notion of harm lends support to a standard of minimal, general, and universal justice. Those actors who are in a position to fulfill its requirements are under a duty to do so. Especially the rich and powerful countries ought to counteract the harmful impact of past greenhouse emissions. (shrink)