For centuries, philosophers have attempted to discover universal truths about the mind by looking inward. Descartes found certainty in the cogito. Kant derived the necessary conditions for all possible experience. Husserl described what he took to be the essential structures of consciousness.

They were all working with the same evidence: a sample of one.

In this groundbreaking work, Boris Kriger proves mathematically what Michel de Montaigne intuited four centuries ago: no amount of introspection can tell us which features of our minds are universal and which are merely our own. The Reflexive Inference Law, formalized here for the first time, shows that subjectivity is not a bias to be overcome but a structural necessity of any finite observer reasoning about its own kind.

This is not a counsel of despair. It is a call for transformation. The emergence of artificial intelligence provides, for the first time in history, access to minds radically different from our own. Philosophy of mind can finally become what it always aspired to be: a genuinely comparative discipline capable of distinguishing the universal from the parochial, the necessary from the contingent.

Drawing on information theory, complexity science, and the essayistic tradition of Montaigne, Kriger offers both a diagnosis of why pure philosophy of mind has reached an impasse and a path forward. The armchair was always limited. Now we can say exactly how, and what comes next.

A rigorous, personal, and ultimately hopeful meditation on the limits and possibilities of self-knowledge.