What you’ve defined above is just morality in general: basically any moral theory can be expressed as a “nonlinear” function of some properties of individuals plus some properties of the world. For example, in deontology one nonlinearity is the fact that murdering someone is nearly-infinitely bad.
The key thing that utilitarianism does is claim that the function we should be maximising is roughly linear in well-being; my main point is clarifying that it shouldn’t be linear in “utility” (in either a desire or an economic sense).
What you’ve defined above is just morality in general: basically any moral theory can be expressed as a “nonlinear” function of some properties of individuals plus some properties of the world. For example, in deontology one nonlinearity is the fact that murdering someone is nearly-infinitely bad.
The key thing that utilitarianism does is claim that the function we should be maximising is roughly linear in well-being; my main point is clarifying that it shouldn’t be linear in “utility” (in either a desire or an economic sense).