Ethics of existential risk

The ethics of existential risk concernsis the study of the ethical issues related to existential risk, including questions of how bad an existential catastrophe would be, how good it is to reduce existential risk, preciselyrisk, why those things are as bad or good as they are, and how this differs between different specific existential risks. There areis a range of different perspectives on these questions, and these questions have implications for how much to prioritise reducing existential risk in general and which specific risks to prioritise reducing.

Ord, Toby (2020) The Precipice: Existential Risk and the Future of Humanity, London: Bloomsbury Publishing.Publishing, ch. 2.

In The Precipice, Toby Ord discusses five different "moral foundations" for assessing the value of existential risk reduction, depending on whether emphasis is placed on the future, the present, the past, civilizational virtues or cosmic significance (Ord 2020).^[1]

In one of the earliest discussions of the topic, Derek Parfit offers the following thought experiment (Parfit 1984: 453–454):experiment:^[2]

The scale of what is lost in an existential catastrophe is determined by humanity's long-term potential—all the value that would be realized if our species survived indefinitely. The universe's resources could sustain a total of around 1035 biological human beings, or around 1058 digital human minds (Bostrom, Dafoe & Flynn 2020: 319).minds.^[3] And this may not exhaust all the relevant potential, if value supervenes on other things besides human or sentient minds, as some moral theories hold. 

Some philosophers have defended views on which future or contingent people do not matter morally (Narveson 1973).morally.^[4] Even on such views, however, an existential catastrophe could be among the worst things imaginable: it would cut short the lives of every living moral patient, destroying all of what makes their lives valuable, and most likely subjecting many of them to profound suffering. So even setting aside the value of future generations, a case for reducing existential risk could grounded in concern for presently existing beings.

This present-focused moral foundation could also be discussed as a "near-termist" or "person-affecting" argument for existential risk reduction (Lewis 2018).reduction.^[5] In the effective altruism community, it appears to be the most commonly discussed non-longtermist ethical argument for existential risk reduction.

Humanity can be considered as a vast intergenerational partnership, engaged in the task of gradually increasing its stock of art, culture, wealth, science and technology. In Edmund Burke's words, "As the ends of such a partnership cannot be obtained except in many generations, it becomes a partnership not only between those who are living, but between those who are living, those who are dead, and those who are to be born."  (Burke 1790: 193)^[6] On this view, a generation that allowed an existential catastrophe to occur may be regarded as failing to discharge a moral duty owed to all previous generations (Ord 2020: 49–53).generations.^[7] 

Instead of focusing on the impacts of individual human action, one can consider the dispositions and character traits displayed by humanity as a whole, which Ord calls civilizational virtues(Ord 2020: 53).^[8] An ethical framework that attached intrinsic moral significance to the cultivation and exercise of virtue would regard the neglect of existential risks as showing "a staggering deficiency of patience, prudence, and wisdom." (Ord, in Grimes 2020)^[9]

At the beginning of On What Matters, Parfit writes that "We are the animals that can both understand and respond to reasons. [...] We may be the only rational beings in the Universe." (Parfit 2011: 31)^[10] If this is...