a.k.a. 'person'
Moral Agency is a concept in moral philosophy and the discussion of ethics.
A Moral Agent is anything that can be held responsible -- credited or blamed -- for decisions or behavior. It is moral agents who have rights and responsibilities, because it is moral agents whom we take to have choices and the power to choose.
If you do not think anyone or anything should ever be blamed, then you are denying the concept of moral agency -- as well as the concept of rights and of responsibilities. (See EGOISM.)
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Being a Moral Agent does not mean that you are successfully making moral decisions or that you are intelligent or that you are righteous. It means that you belong to that category of being that can be blamed. If we can't blame you, you have no rights. If you have no rights, we can't blame you. It means that we get to hold you responsible for the decisions you make, no matter how well or poorly you make them.
If the guy who beats me up isn't a moral agent, then I can't blame him for what he did -- I have to treat him as a force of nature. Blaming someone MEANS that you are treating him as a moral agent. Without the concept of moral agency -- the idea of choice -- there can be no SHOULD or SHOULDN'T.
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The number 4 is not a physical agent. It cannot do anything in the physical world.
A tornado is a physical agent because it can and does do things in the physical world.
But a tornado can't do anything in the moral world. It can destroy my house, but it can't rob me of my property in the same sense that a person can.
A person is a moral agent. I care differently if my house is destroyed by a tornado than I do if it's destroyed by a terrorist. The terrorist robbed me of my house, because, unlike the tornado, the terrorist can do things in the moral world, and 'to rob' is a morally-defined term.
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