The theory that being good is a simple property that is irreducible or indefinable interms of anything else.

The theory you are referring to is likely related to ethical philosophy and the debate around moral realism, specifically the “simple property” view of goodness. This concept can be connected to metaethics, which examines the nature of moral judgments and the status of moral values.

1. Moral Realism: This position holds that there are objective moral truths, and when we make moral statements, we are expressing beliefs about these truths. In this context, being "good" may be considered an irreducible property because it exists independently of our perceptions or cultural beliefs.

2. Indefinable Goodness: The assertion that goodness cannot be defined in terms of other properties suggests that it is a fundamental aspect of moral philosophy. Philosophers like G.E. Moore argued against naturalism, stating that one cannot reduce moral properties to natural properties (e.g., pleasure, desire satisfaction). Moore famously introduced the "open-question argument," which asserts that no matter how much you define "good," it remains an open question whether that definition truly captures the essence of goodness.

3. Implications: If goodness is considered an irreducible property, it raises questions about how we understand moral language, ethical theories, and moral obligations. This concept challenges various ethical frameworks that attempt to base morality on empirical or purely rational principles.

In essence, the view that goodness is a simple, indefinable property emphasizes the complexity of moral discourse and the nature of ethical truths, advocating for a more nuanced understanding of moral statements and their implications in practical ethics.