Summer School 2025（Qstr-IIT Summer School、イタリア）参加者の Kallum Robinson さんが、同スクールの講師 3 名（Giulio Tononi さん、領域代表 土谷尚嗣さん、Matteo Grasso さん）と共著で執筆した論文が、プレプリントとして arXiv で公開されました。全文をお読みいただけます。ぜひご一読ください。

本章は、2025 年にイタリアで開催された Qstr-IIT Summer School から直接生まれた成果です。また、Springer Nature より 2027 年刊行予定の書籍「Qualia Structure」に収録される予定です。

Paper Information

Authors: Kallum Robinson, Giulio Tononi, Naotsugu Tsuchiya, and Matteo Grasso

Title: The Rosetta Stone and Levels of Principled Inference to the Experience of Another Mind

Preprint: arXiv:2608.12030 [q-bio.NC]（2026 年 8 月 12 日公開）

Note: To appear in Qualia Structure, Springer Nature（2027年刊行予定）

DOI: https://doi.org/10.48550/arXiv.2608.12030

概要

　構造的アプローチは「他我問題（the problem of Other Minds）」の解決に役立つのでしょうか。本論文では、経験を数理的構造として翻訳する「ロゼッタ・ストーン」の候補として、クオリア構造パラダイム（Qstr）と統合情報理論（IIT）を比較しています。いずれのアプローチも、他者の経験を直接知ることを隔てる「acquaintance gap（直知の隔たり）」を越えることはできません。しかし圏論を用いることで、構造どうしの対応関係（同型から強・弱の随伴、そして推論の限界点まで）が、他者の心について何をどこまで推論してよいかを原理的に制約する枠組みになることを示しています。

Abstract

 The classical problem of Other Minds has dogged philosophers for millennia; asking if we have any way to truly understand the experience of another mind. We know our own intrinsic experience by acquaintance, but can only ever hope to possess an extrinsic description of another’s, with the two separated by an acquaintance gap. Structural approaches aim to characterise experience in terms of a mathematical structure, and promise a ‘Rosetta Stone’; that is, a principled method to translate the contents of experience into a mathematical structure. In this chapter, we examine two such approaches - the Qualia Structure Paradigm (Qstr) and Integrated Information Theory (IIT) - to ask what, if anything, they allow us to infer about another mind should they possess the Rosetta Stone they seek. Qstr proceeds inter-phenomenally; aiming to exhaustively characterise an experience by its relations to all other experiences and providing a necessary condition on the sameness of experience. IIT proceeds intra-phenomenally; conjecturing that a single experience is accounted for by the cause-effect structure unfolded from a substrate in a state, an explanatory identity that is both necessary and sufficient for the sameness of experience. While neither approach can cross the acquaintance gap to another’s mind, they provide a common formal medium through which minds may be compared and in turn reduce the size of this gap. We identify the strength of inference with the levels of structural correspondence in Category Theory. These descend from isomorphism through strong and then weak adjunction, to a principled limit where inference runs out entirely. We conclude that these structural approaches and the existence of their respective Rosetta Stones would not solve the problem of Other Minds, but instead provide a system of principled constraints on what we may infer, which is far more than what has been justifiable before.