Imagine there were some sort of prohibition against making things worse for others.
I assume some ethicists claim that anyway: but
Especially interested in "critical theory", I suppose.
My apologies for stating the obvious, but as we all know, definitions are, at some level, arbitrary. We can define morality in any way we choose, but we do have some sort of understanding among other people, allowing for 'useful' and 'useless' definitions.
That being said, harm is a label that we place on a very specific set of perceived stimuli. Namely, stimuli that induce an undesirable effect within our minds (or, more Scientifically, brains). It can surely be tailored more, because activities like exercise create short-term undesirable effects like tiredness or exhaustion, but for the sake of argument, we will leave it at that. Harm can be determined with epistemic objectivity by several ways, but the two stand stand out to me are:
Either way, it would be epistemically objective that an agent is feeling harmed, though it tells us nothing of what is harming them, or even if they are actually being harmed.
Well in theory we could just ask everyone, did that hurt you? That's not really going to work. Is it? Even if our population is manageable, say a small city of ~100, you'll have a slew of other factors playing in the individual's response. Do they take it as a matter of pride not to be hurt? Do they perceive an honest "yes" as a potential door that, when opened, leaves them vulnerable to other intrusions? Who is asking? Do they like this person?
It's easy to get caught up in the problems of implementation. But let's assume we ask more or less directly and our system works at around 70% accuracy for defining "harm". We've decided to go forward knowing we'll be uncertain about 30% of all our decisions. This is basically the situation we have, though most politicians act more confident in knowing than they reasonably could be. The actual accuracy of our system is effectively unknowable, but we have to move forward.
So we want to stop people from hurting each other? Prohibition is probably the least efficient way we could go about it. I'll cite the wild successes of the Prohibition movement. Anyone can cause harm, it's precisely the problem. People who have more swing will have a greater capacity for causing harm and will have greater capability of getting around our attempts at blocking harm. It is just now dawning on those in the realm of social ethics that we shouldn't be fighting harm directly. The best way to go about it is to understand and influence the conditions in which harm arises.
To have "harm" requires there to exist an individual to be harmed. I am unaware of any philosophical argument that a thing can be harmed unless that thing is a mental entity. Obviously one can harm another human, perhaps by cutting off their arm, which is clearly a physical act, but the fact that such an act is "harmful" is dependent on the existence of a mental entity to observe harm. Even in the case of a functionalist, who believes the mind is an illusion, still only applies the term "harm" in the context of that illusion. Even in the case of non-ethical use of the word, such as "Don't harm the paint job on the boat," the concept is associated with the concept of the boat's paint job, and that your act makes it less ideal -- less able to accomplish that which its ideal mental image supports.
So, for any given individual which may be harmed, they may define a metric which divides tasks into "harmful" or "not harmful." Some individuals like soothsayers may be able to claim to identify if a task is harmful or not. Normal folk like us appear to use a heuristic to decide if something was harmful and may change our mind if the heuristic proved to be faulty (key takeaway: what an individual claims is harm and what is actually harm to the individual may not be the same).
I will be the first to recognize that such a definition is too broad for use, and that is intentional. From the comments, I draw the assumption that the exact definition differs from philosopher to philosopher. However, this overly broad wording may be an effective lens with which to identify what any individual philosopher believes.
