The performative point of [§2.2.1](<2.2.1 Change Is Actual.md>) applies once more, now at the chapter's close. It does not re-establish the necessity already derived: that work is done. What it confirms is that the derived necessity cannot be coherently denied: to dismiss Nature as a cognitive projection is itself a change of mental state, and to formulate the thought that Nature might not have existed is to instantiate the Conditions whose non-existence is being proposed. Descartes' *cogito* used the act of thinking to prove the existence of a thinking subject. This point is narrower, and it is one application of the performative-catch principle established at [§2.2.1](<2.2.1 Change Is Actual.md>): to think is to change, which instantiates Temporality, Spatiality, and Physicality.

*Cogito ergo muto*: I think, therefore I change.

The strongest single case of the denial form is the conversion event itself. To come to conclude that any X is illusory is to perform a change of mind: a before-state in which the thesis was not held, an after-state in which it is, a bearer who is the same across both, and a synthesis integrating the consideration that produced the change. The conversion event has T, S, Φ, and synthesis baked into its concept, not into its accidental features. The illusionist about time ([§4.2.5](<4.2.5 The Unreality of Time.md>)), about Forms ([§4.2.4](<4.2.4 Platonism.md>)), about imagination's spatial structure ([§4.3.5](<4.3.5 Idealism.md>)), about the persisting self ([§8.5](<8.5 Identity.md>)) cannot have *come to hold* the thesis without performing the very kind of event whose structural conditions the thesis denies. The denial is performatively caught by the conversion to the denial; whether the conversion itself can be redescribed away is the engagement of Chapter 4.[^2-8-2-cogito-ergo-muto-ch4]

[^2-8-2-cogito-ergo-muto-ch4]: The performative-confirmation reading (whether the cogito-style move at the chapter's close adds anything beyond [§2.2.1](<2.2.1 Change Is Actual.md>), and whether thinking-is-changing genuinely instantiates T, S, and Φ) is engaged in Chapter 4. The strongest opponents of the *thinking is changing* premise are eliminativism and illusionism about mental states ([§4.3.2](<4.3.2 Eliminativism and Illusionism.md>)), while idealism accepts the premise but reads the change as wholly mental rather than as structural T∧S∧Φ ([§4.3.5](<4.3.5 Idealism.md>)).


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← [2.8.1 Laws as Constitutive](<2.8.1 Laws as Constitutive.md>) | [2.8.3 Not Physicalism](<2.8.3 Not Physicalism.md>) →
