Conceptual guardrails
Points that are easy to get wrong when reviewing outside work on IIT or answering an objection. Each guardrail is stated by Giulio Tononi (2026), followed by where the corpus supports it.
Evidence comes from ourselves. IIT is consciousness-first: it is grounded in our own experience and validated on its substrate in us. Never describe the source of evidence as "systems that can report" or "report". Sources: Tononi & Boly 2025, "Introduction: experience as intrinsic existence" (the empirical validation of IIT is "established in ourselves"; its attribution to others "is necessarily a matter of inference") and "Inferring consciousness beyond adult humans".
Inference, not prediction. IIT's verdict on a system we cannot validate against (a computer, a feedforward equivalent, an organoid) is an inference from a good explanation validated in ourselves. A behaviorally matched system without integrated information is neither a behavioral "prediction" to be tested nor a counterexample. Treating it as either accepts the premise of the unfolding argument. Sources: Tononi & Boly 2025, "Some implications of IIT: meaning, perception, and matching" ("inferences from a good explanation") and "Inferring consciousness beyond adult humans"; the ledger entry on the unfolding argument.
Large Φ in a regular grid is expected, not a reductio. IIT concluded this already in 2.0, and the 2014 reply to Aaronson and the extendedness papers (Haun & Tononi 2019; Grasso et al. 2021, 2026) treat lattice Φ-structures as what accounts for spatial experience. A realistic large complex also needs near-determinism with some indeterminism, the right grain, and the high fan-in/fan-out that physical grids lack. Sources: Balduzzi & Tononi 2008; Tononi 2014, "Why certain grids may be conscious"; Haun & Tononi 2019; Grasso et al. 2021; Grasso et al. 2026; Tononi & Boly 2025, "Grids" and "IIT and the richness of experience" (cooperative but specialized macro units, "a large fan-in/out to promote integration", "a sufficiently regular lattice"); Mayner, Marshall & Tononi 2026, §4 (the tradeoff between determinism and indeterminism); Marshall et al. 2026 (grain).
The human main complex is posterior-central. Say "posterior-central integrated information", not "posterior cortical integration". Source: the term Tononi & Boly 2025 use throughout, e.g. "IIT and the richness of experience" ("a large main complex in the human brain, most likely in posterior-central cortex").
Inactive vs. inactivated. Inactive units in the complex contribute to the Φ-structure; inactivated units do not. Don't conflate them. Sources: the IIT wiki, "Validate empirically in humans" and its footnote 1; Tononi & Boly 2025, "The quality of experience: space is extended" (a largely inactive main complex in a state of causal readiness).
Boundary and grain are outputs of exclusion, never chosen by the investigator before the analysis. Sources: the exclusion postulate; Albantakis et al. 2023, "Exclusion: Determining maximal substrates (complexes)" and "Determining maximal unit grains", Eqs (24)–(26); Marshall et al. 2026, "Intrinsic units".
Hardware, not software. Candidate units are physical; weights and activations are virtual. Changing a network's architecture on fixed hardware does not change intrinsic causal organization, and perturbational measures on model activations do not test IIT. Sources: Tononi & Boly 2025, "Intrinsic meanings vs. extrinsic referents" (an LLM's units, "being simulated on a computer, are virtual"); Findlay et al. 2025, "Cause–effect structures specified by the computer can be dissociated from those of target systems it is simulating". The last clause, about perturbational measures, follows from the units being virtual; no source states it in those words.
Know which φs an outside paper uses. Under the current φs (Mayner, Marshall & Tononi 2026) a purely deterministic system has φs = 0. Many outside results still use 2023 φs. Sources: φs, including "Before 2026"; Mayner, Marshall & Tononi 2026, §2.2–2.3; what is current.
Check before calling something an objection. Much outside criticism restates what IIT already holds; search the corpus and the ledger first.