Final Answer:
The definition of ability, without invoking possible worlds, can be framed as the capacity or potential of an entity (X) to perform a certain action or achieve a specific state (Y). This definition focuses on the inherent capability of an entity, acknowledging that the actualization of the ability may not be realized.
Step-by-step explanation:
In philosophy, discussions about the concept of ability often fall under the purview of action theory. The non-modal definition proposed emphasizes the inherent capacity of an entity to engage in certain actions or possess specific attributes.
This aligns with the idea that ability is tied to potentiality, reflecting the inherent capabilities an entity possesses. Philosophers such as R. Jay Wallace and John Martin Fischer have explored action theory and the concept of abilities within a non-modal framework.
References to delve deeper into this topic include R. Jay Wallace's "Normativity and the Will: Selected Essays on Moral Psychology and Practical Reason" and John Martin Fischer's "Responsibility and Control: A Theory of Moral Responsibility." These works contribute to the understanding of ability and action theory without relying on ontologically extravagant notions such as possible worlds.
The proposed definition aligns with the philosophical discourse on abilities, emphasizing the intrinsic potential of entities to engage in specific actions or states without venturing into the realm of modal metaphysics.