Staking our future: deontic longtermism and the non-identity problem

Abstract

Greaves and MacAskill argue for axiological longtermism, according to which, in a wide class of decision contexts, the option that is ex ante best is the option that corresponds to the best lottery over histories from t onwards, where t is some date far in the future. They suggest that a stakes sensitivity argument may be used to derive deontic longtermism from axiological longtermism, where deontic longtermism holds that in a wide class of decision contexts, the option one ought to choose is the option that corresponds to the best lottery over histories from t onwards, where t is some date far in the future. This argument appeals to the Stakes Principle: when the axiological stakes are high, non-consequentialist constraints and prerogatives tend to be insignificant in comparison, so that what one ought to do is simply whichever option is best. I argue that there are strong grounds on which to reject the Stakes Principle. Furthermore, by reflecting on the Non-Identity Problem, I argue that there are plausible grounds for denying the existence of a sound argument from axiological longtermism to deontic longtermism insofar as we are concerned with ways of improving the value of the future of the kind that are focal in Greaves and MacAskill’s presentation.

Introduction

How should we choose between the present and the future? Some of the most pressing problems that we face are fleeting when viewed in historical perspective. Millions currently suffer in extreme poverty. However, the percentage of people living in extreme poverty fell dramatically near the end of the 20th century, virtually halving between 1990 and 2010. It could well fall to zero within our lifetimes (The Economist 2013). Other problems that press upon us will spread across the very long run. Climate change is the most salient example. CO2 released into the atmosphere today has the potential to affect the climate for thousands of years into the future (Archer et al. 2009). In deciding which problems to prioritize, should we be more concerned about the present or the future?

Hilary Greaves and William MacAskill (2019) argue that the future should typically have priority. More specifically, they argue for a thesis they call axiological longtermism. Axiological longtermism is a hypothesis about so-called ex ante axiology, which involves ranking probabilistic prospects as better or worse (Broome 1991). Any such prospect may be called a lottery. In their formulation, axiological longtermism says that in a wide class of decision contexts, the option that is ex ante best is the option that corresponds to the best lottery over histories from t onwards, where t is some date far in the future. Thus, we could pick t to be the year 2312. Axiological longtermism tells us that if we are comparing different options and we want to rank their associated prospects as better or worse from the moral point of view, we can in many cases effectively ignore possible outcomes associated with the years 2019-2312 and rest our comparison entirely on the probability distribution over possible outcomes associated with the oceans of time that fall between the year 2312 and the heat death of the universe.

The argument that underpins this view is easy to grasp. When we evaluate acts in terms of their consequences, all of their consequences should be counted, no matter how distant in space or time. Furthermore, the long-term future is potentially vast. There is so much more time between 2312 and the heat death of the universe than there is between 2019 and 2312. There are so many more people who could populate that time. It should therefore be easy to see why we might think that the potential effects of our actions distributed across those gigantic possible future populations should carry more weight than their near-term effects, which concern far fewer people.

The action that is associated with the best prospect need not be considered obligatory (Kamm 2000). We may believe, for example, that the ends do not always justify the means: that certain outcomes, although they would be better as outcomes than any others we could realize, ought not to be brought about because they cannot be achieved without violating people’s fundamental rights. In other words, we may believe in side-constraints on permissible harm (Nozick 1974: 28-33). Or we may believe that although some outcome would be morally best, we are not obligated to bring it about because the personal cost would be too great. In other words, we may believe in agent-centred prerogatives that allow us to care about our own interests out of proportion to their significance considered impartially (Scheffler 1991). There is, therefore, a logical gap between axiological longtermism and deontic longtermism, where the latter holds that in a wide class of decision contexts, the option one ought to choose is the option that corresponds to the best lottery over histories from t onwards, where t is some date far in the future.

Is there some way to bridge this gap? Or might it be that axiological longtermism is true while deontic longtermism is false?

Greaves and MacAskill propose to bridge this gap by appeal to a stakes sensitivity argument. As we have noted, not only is humanityЃs total potential future greater than its nearϳterm future history, it is vastly greater. As a result, it is plausible that the best ways of affecting the long run future are vastly better than the best ways of affecting the short run. Greaves and MacAskill appeal to the principle that when the axiological stakes are high, nonϳconsequentialist constraints and prerogatives tend to be insignificant in comparison, so that what one ought to do is simply whichever option is best. Let’s call this the Stakes Principle.

The Stakes Principle is plausible on its face. It is natural to think that in order to decide on the right action in any given case, we need to weigh up the different competing considerations that apply in that case. Promoting the good matters, but so does respect for individual rights, and loyalty to one’s self and one’s nearest and dearest. Balancing these competing considerations means that if any one among them is is sufficiently weighty in comparison with the others, it will carry the day, just as it is always possible to tip a pair of scales by adding sufficient weight to one side. Respect for individual rights is important, but if the good that could be achieved by violating some right is great enough, that is what we should do. So says the Stakes Principle, and so say most of us.

In this paper, I will argue that the Stakes Principle is nonetheless false. Furthermore, I will present a prima facie plausible view about the relationship between value and obligations in the context of the Non-Identity Problem that suggests that axiological longtermism is true but deontic longtermism is false, even granting that the value at stake over the very long run is astronomical in comparison with the value at stake within the near-term. The overall plausibility of this view deserves further scrutiny, but indicates the existence of a significant obstacle to bridging the gap between consequentialist and deontological perspectives on the moral significance of the long run future.

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