They are closely related to but not identical with various other concepts, such as disposition, know-how, aptitude, talent, potential, and skill.
Some counterexamples involve cases in which the agent is physically able to do something but unable to try, due to a strong aversion.
Another distinction concerns the question of whether successfully performing an action by accident counts as having the corresponding ability.
The debate between compatibilism and incompatibilism concerns the question whether this ability can exist in a world governed by deterministic laws of nature.
Autonomy is a closely related concept, which can be defined as the ability of individual or collective agents to govern themselves.
Actions are usually defined as events that an agent performs for a purpose and that are guided by the person's intention,[2][3] in contrast to mere behavior, like involuntary reflexes.
Dispositions, for example, are often equated with powers and differ from abilities in the sense that they are not necessarily linked to agents and actions.
[9] The term "disability" is usually used for a long-term absence of a general human ability that significantly impairs what activities one can engage in and how one can interact with the world.
[21] Closely related to this is the converse problem concerning lucky performances in the actual world.
This problem concerns the fact that an agent may successfully perform an action without possessing the corresponding ability.
[22][19] So a beginner at golf may hit the ball in an uncontrolled manner and through sheer luck achieve a hole-in-one.
[21][22][19] A series of arguments against this approach is due to Anthony Kenny, who holds that various inferences drawn in modal logic are invalid for ability ascriptions.
[19] It has also been argued that, strictly speaking, the conditional analysis is not different from the modal approach since it is just one special case of it.
This is true if conditional expressions themselves are understood in terms of possible worlds, as suggested, for example, by David Kellogg Lewis and Robert Stalnaker.
[23][24][25] This view is closely related to the conditional analysis but differs from it because the manifestation of dispositions can be prevented through the presence of so-called masks and finks.
[18] Another distinction sometimes found in the literature concerns the question of whether successfully performing an action by accident counts as having the corresponding ability.
[21][29] For example, a student in the first grade is able, in a weaker sense, to recite the first 10 digits of Pi insofar as they are able to utter any permutation of the numerals from 0 to 9.
Free will is closely related to autonomy, which concerns the agent's ability to govern oneself.
Another issue concerns whether someone has the moral obligation to perform a certain action and is responsible for succeeding or failing to do so.
It has been argued that, according to a dispositionalist theory of ability, compatibilism is true since determinism does not exclude unmanifested dispositions.
[13] Peter van Inwagen and others have presented arguments for incompatibilism based on the fact that the laws of nature impose limits on our abilities.
[35] Robert Audi, for example, characterizes autonomy as the self-governing power to bring reasons to bear in directing one's conduct and influencing one's propositional attitudes.
[39] Some authors include the condition that decisions involved in self-governing are not determined by forces outside oneself in any way, i.e. that they are a pure expression of one's own will that is not controlled by someone else.
[14] In the Kantian tradition, autonomy is often equated with self-legislation, which may be interpreted as laying down laws or principles that are to be followed.
This involves the idea that one's ability of self-governance is not just exercised on a case-by-case basis but that one takes up long-term commitments to more general principles governing many different situations.
[43] According to this principle, for example, a person sitting on the shore has no moral obligation to jump into the water to save a child drowning nearby, and should not be blamed for failing to do so, if they are unable to do so due to Paraplegia.
[32] But some authors, often from the incompatibilist tradition, contend that what matters for responsibility is to act as one chooses, even if no ability to do otherwise was present.
[45][46] So a person is usually able to attend a meeting 5 minutes from now if they are currently only a few meters away from the planned location but not if they are hundreds of kilometers away.
This seems to lead to the counter-intuitive consequence that people who failed to take their flight due to negligence are not morally responsible for their failure because they currently lack the corresponding ability.
On the other hand, this person should be able to point out what follows from the fact that something is a wombat, e.g. that it is an animal, that it has short legs or that it has a slow metabolism.