Hi everyone!


I have the following question about utilitarianism. If you define

a utility function u, you have to sum over the welfare of all

sentinent beings. It is more or less possible to decide if

the welfare of one being is greater than the welfare of another being.

In order to determine the total utility an order relation is not

enough. In addition you have to assign a numerical value

to the individual welfare. Depending on how you choose

this value the best decisions can be vastly different.


To illustrate my point I introduce the following toy model: Let

there be n classes of sentinent beings whose mental

capacibilities are comparable. The first class could be insects,

the second rodents, the third apes, the fourth humans

and the fifth AIs with superhuman mental capacibilities.

I denote the set of all happy beings in the class i by

 and the set of all suffering beings by . The

number of all beings in  should be .


By observing the behaviour or the brain architecture

of the beings, we can get a rough idea if individuals in

 have higher cognitive functions / a higher

welfare than members of  (although even this may be

debatable). Mathematically speaking we have an order relation

on . In order to determine the total

utility u we need a monotonous function

 such that



If f has large negative values for negative indices, we

obtain suffering focused ethics. If f is nearly constant

for positive indices, the ideal world would be populated only

by happy insects, since a fixed area can support more of

them. If f is nearly zero for non-human animals and 1

for humans and AIs, the ideal world would be populated by

as many happy humans (or emulated minds) as possible

and AI development would not be a high priority. If f

is increasing very fast, it would be the best to develop

superhuman AIs as fast as possible even at the expense of humans.


My question is if there is a non-arbitrary way to determine

f. It may be possible to define f in such a way

that it captures most of ethical intuitions. I am not sure

if this approach is to subjective, but I do not see how

to define f in terms that can be measured.



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Hi Frank, I am not sure I completely understand your questions.

Are you talking about interspecies comparisons of utility (differences)? I.e., how can we determine whether these 20 insects are happier than this one human 

or (about utility differences) that giving food to 20 insects results in more additional utility than giving the food to one human?

Literature I can recommend is: 


Dawkins, M.S. (1990). From an Animal's Point of View: Motivation, Fitness, and Animal Welfare. Behavioral and Brain Sciences, 13(1), pp.1–9.

Fleurbaey, M., and Hammond P.J. (2004). Interpersonally Comparable Utility. In: Barberà, S., Hammond, P.J., and Seidl, C. (eds) Handbook of Utility Theory. Springer, Boston, MA. https://doi.org/10.1007/978-1-4020-7964-1_8

Budolfson, M. and Spears, D. (2020). Quantifying Animal Well-being and Overcoming the Challenges of Interspecies Comparisons. In: Bob Fischer (ed.), The Routledge Handbook of Animal Ethics

Roberts, K. (1997). Objective Interpersonal Comparisons of Utility. Social Choice and Welfare, vol. 14, pp. 79–96.

There is also a forum post about the topic here by Jason Schukraft.

Or are you just generally talking about Social Choice Theory?

Happy to help if this does not yet answer your question.

My question was mainly the first one. (Are 20 insects happier than one human?) Of course similar problems arise if you compare the welfare of humans. (Are 20 people whose living standard is slightly above subsistence happier than one millionaire ?) 

The reason why I have chosen interspecies comparison as an example is that it is much harder to compare the welfare of members of different species. At least you can ask humans to rate their happiness on a scale from 1 to 10. Moreover, the moral consequences of different choices for the function f are potentially greater.

The forum post seems to be what I have asked for, but I need some time to read through the literature. Thank you very much!