محمدمهدی منادی

SUBJECT & OBJECTIVES: Ontological inquiry constitutes one of the central concerns of metaethics. Within this field, theories are commonly divided into two main categories: realist and non-realist. While this primary distinction is well established, the secondary classifications and internal variations within realism have received comparatively little attention. Many of the enduring ambiguities in moral philosophy arise from the lack of a precise differentiation among realist positions. This study aims to address that gap by re-examining the ontological foundations and typological distinctions within moral realism. METHOD & FINDING: Using an analytical–descriptive method, this study differentiates between two distinct forms of moral realism—rationalist realism and sentimentalist realism—and explicates their respective implications. Representative approaches of sentimentalist realism include hedonism, Isaiah Berlin’s notion of negative liberty, Karl Popper’s reduction of suffering, and Benthamite utilitarianism. In contrast, MacIntyre’s virtue ethics, scientism, and perfectionism exemplify rationalist realism. The implications of rationalist realism can be summarized as follows: 1. The possibility of rational justification for moral judgments; 2. The dependence of moral values on ontological realities; 3. The possibility of moral preference in cases of ethical conflict based purely on ontological grounds; 4. The capacity to identify and prioritize the virtuous individual; 5. The derivability of “ought” from “is” on rational premises alone; 6. Monism is grounded in a single rational proposition; 7. Absolutism grounded in an absolute rational principle. CONCLUSION: While sentimentalist realism shares certain structural features with other realist frameworks, it diverges from rationalist realism in several essential respects, particularly regarding the role of sentiment, taste, and individual inclination in grounding moral value. This distinction underscores the need for a more nuanced typology of moral realism within contemporary metaethical discourse.