Jen Zhu: The Mathematics of Morality

jzhu@college.harvard.edu

The clear boundary between “good” and “bad” has been an ethical dilemma that humankind has struggled with – and continues to struggle with – throughout its entire existence. Looking at morality through a utilitarian mindset, the meaning of life is to maximize wellbeing for as many people as possible by minimizing experience suffering. This seems easy enough: all you have to do is choose what is best for the most amount of people, right? Although the concept is theoretically simple, once you factor in the characteristics of humanity – especially how big of an impact emotion has on our “rational” decision making – the process is much more difficult.

Take the typical trolley example used in psychological studies: would you rather pull a trigger to send a trolley down a different path running over one person, or allow it to continue on its current path sending five people to their deaths? Sitting down reading this blogpost, you probably think that the decision is clear; looking at the numbers, saving five people is more impactful than saving one, so pulling the switch is the “right” moral decision you think you would make. Now, let’s factor in emotions. Looking at the problem more carefully, the two options are not exactly equal. In one, you observe five people plummet to their death without acting, a passive option. In the other, while you save a difference of four lives, you yourself are actively pulling a switch leading to someone’s death – murder, if you purely consider the definition. Although passively allowing people to die and actively making the move leading to their death leads to the same consequentialist result, the actions – and what we as humans make our decisions based on – leads us to question decision-making based on science.

In addition, consider this argument: would you rather give one developing country $9 million dollars of economic aid, or two developing countries $4 million each? Both developing countries need the money. Looking at this from a purely utilitarian perspective, giving one country $9 million dollars has a greater total increase in overall wellbeing than giving two countries $8 million dollars (since 9 > 8). However, by the principle of diminishing marginal utility, the additional benefit a country gains from receiving $8 billion compared to $9 billion is much smaller than the benefit a country would gain from receiving $1 billion rather than $0. While one country is focusing on enhancement and wellbeing, the other country is focused on survival. In this case, numbers are not all equal.

Clearly, the science behind making moral decisions is not so straightforward as it may seem. Rather than just adding or multiplying the numbers, we must consider the background factors that influence every decision – no matter small or large – we make as humans. In the future, our human nature may change so much that decisions can be made through simple calculations. However, for now, moral calculations will continue to be based on combinations of emotions rather than permutations of numbers.