Moral agency is an individual's ability to make moral choices based on some notion of right and wrong and to be held accountable for these actions. A moral agent is "a being who is capable of acting with reference to right and wrong."
Most philosophers suggest only rational beings, who can reason and form self-interested judgments, are capable of being moral agents. Some suggest those with limited rationality (for example, people who are mildly mentally disabled or infants) also have some basic moral capabilities.
Determinists argue all of our actions are the product of antecedent causes, and some believe this is incompatible with free will and thus claim that we have no real control over our actions. Immanuel Kant argued that whether or not our real self, the noumenal self, can choose, we have no choice but to believe that we choose freely when we make a choice. This does not mean that we can control the effects of our actions.
Some Indeterminists would argue we have no free will either. If, with respect to human behaviour, a so-called 'cause' results in an indeterminate number of possible, so-called 'effects', that does not mean the person had the free-thinking independent will to choose that 'effect'. More likely, it was the indeterminate consequence of his chance genetics, chance experiences and chance circumstances relevant at the time of the 'cause'.
In Kant's philosophy, this calls for an act of faith, the faith free agent is based on something a priori, yet to be known, or immaterial. Otherwise, without free agent's a priori fundamental source, socially essential concepts created from human mind, such as justice, would be undermined (responsibility implies freedom of choice) and, in short, civilization and human values would crumble.
It is useful to compare the idea of moral agency with the legal doctrine of mens rea, which means guilty mind, and states that a person is legally responsible for what he does as long as he should know what he is doing, and his choices are deliberate.