A paper by Kallum Robinson, a participant in the 2025 Qstr-IIT Summer School in Italy, co-authored with three of the school's lecturers (Giulio Tononi, our representative Naotsugu Tsuchiya, and Matteo Grasso), has been released as a preprint on arXiv. The full text is available. We invite you to read it!

This chapter is a direct output of the Qstr-IIT Summer School held in Italy in 2025. It will also form part of the book Qualia Structure, scheduled for publication by Springer Nature in 2027.

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] (released on 12 August 2026)

Note: To appear in Qualia Structure, Springer Nature (scheduled for publication in 2027)

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

Summary

 Can structural approaches help with the problem of Other Minds? This chapter compares the Qualia Structure Paradigm (Qstr) and Integrated Information Theory (IIT) as candidate “Rosetta Stones” for translating the contents of experience into mathematical structure. Neither approach can cross the acquaintance gap that separates our own experience from another’s. By identifying the strength of inference with the levels of structural correspondence in Category Theory — descending from isomorphism through strong and then weak adjunction, to the point where inference runs out — the authors show how such correspondences can place principled constraints on what we may infer about other minds.

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.