I've been thinking about how people devise ethical systems, and if in fact we could create an ethical system that allows for positive command. I think I, and probably most people I meet, am at my core a utilitarian as it feels the most intuitively isomorphic way of expressing ethical inclination. However, there keep being wrenches thrown in to that general worldview, and I'm wondering whether a perfect system could allow for positive command.
For example, the difficult case of the Kitty Genovese wherein I'm genuinely agnostic whether people could be held accountable for not acting. Similarly, Philippa Foot's famous (and by this point infamous) raises serious concerns about this fundamentally utilitarian ideal - and its similar cases lead me to reconsider the principle entirely.
So, would I want to accept a society that imposed a command of "Thou shalt give x amount of charity every day" (or something along those lines).
My gut reaction is no. It feels too intrusive and restrictive. And, if we just extrapolate upwards, it then becomes easy to reject all notions of positive command, and to want to build a system with only negative commands (i.e. "Thou shalt not kill").
However, this is only a possible consideration if there exist moral commands which can not be cogently expressed by their negation. For the example above, I'm trying to figure out a way to express the idea of "Thou shalt give x amount of charity every day" as a negative command, but I can't think of an example. The only things that come to mind are "Thou shalt not pass by a struggling neighbor or a struggling friend or a struggling [fill in the blank]..." ad infinitum. To express this idea in a negative, one would need to express every possible scenario which one cannot allow for, and using the principle of plenitude, this is uncountably many and therefore impossible. So, to my mind, the idea of "Thou shalt give charity" feels inexpressible in its negation in a finite sense, and therefore should not be included in our moral system.
My question is am I wrong? Is it actually possible to express any theorem or command finitely (or, cogently) by its negation? Or, would this maybe be a good boundary for an ethical system?