Diagnosing Moral Reasoning Acquisition in Language Models: Pragmatics and Generalization

Guangliang Liu, Zimo Qi, Xitong Zhang, Lei Jiang, Kristen Johnson


Abstract
Ensuring that Large Language Models (LLMs) return just responses which adhere to societal values is crucial for their broader application. Prior research has shown that LLMs often fail to perform satisfactorily on tasks requiring moral cognizance, such as ethics-based judgments. While current approaches have focused on fine-tuning LLMs with curated datasets to improve their capabilities on such tasks, choosing the optimal learning paradigm to enhance the ethical responses of LLMs remains an open research debate. In this work, we aim to address this fundamental question: can current learning paradigms enable LLMs to acquire sufficient moral reasoning capabilities? Drawing from distributional semantics theory and the pragmatic nature of moral discourse, our analysis indicates that performance improvements follow a mechanism similar to that of semantic-level tasks, and therefore remain affected by the pragmatic nature of morals latent in discourse, a phenomenon we name the pragmatic dilemma. We conclude that this pragmatic dilemma imposes significant limitations on the generalization ability of current learning paradigms, making it the primary bottleneck for moral reasoning acquisition in LLMs.
Anthology ID:
2025.findings-emnlp.374
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2025
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
7103–7117
Language:
URL:
https://preview.aclanthology.org/author-page-yu-wang-polytechnic/2025.findings-emnlp.374/
DOI:
10.18653/v1/2025.findings-emnlp.374
Bibkey:
Cite (ACL):
Guangliang Liu, Zimo Qi, Xitong Zhang, Lei Jiang, and Kristen Johnson. 2025. Diagnosing Moral Reasoning Acquisition in Language Models: Pragmatics and Generalization. In Findings of the Association for Computational Linguistics: EMNLP 2025, pages 7103–7117, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
Diagnosing Moral Reasoning Acquisition in Language Models: Pragmatics and Generalization (Liu et al., Findings 2025)
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https://preview.aclanthology.org/author-page-yu-wang-polytechnic/2025.findings-emnlp.374.pdf
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