thesis

the principle of organisational invariance, stating that (247)
consciousness arises in virtue of the functional organisation of the brain. On this view, the
chemical and indeed the quantum substrate of the brain is irrelevant to the production of con-
sciousness. What counts is the brain’s abstract causal organisation, an organisation that might
be realised in many different physical substrates.
Functional organisation is best understood as the abstract pattern of causal interaction between
various parts of a system, and perhaps between these parts and external inputs and outputs.
Chalmers calls himself a ‘nonreductive functionalist’, believing that “conscious experi-
ence is determined by functional organisation, but it need not be reducible to functional or-
ganisation” (275).
The Resultant Theory
As a result of the five principles outlined above, Chalmers has little room for manoeuvre
when it comes to developing his theory. His demand for naturalism means that there must
be psychophysical laws connecting physical brain events to experienced phenomenology.
The principle of structural coherence means that these laws must match cognition closely to
experience. The principle of organisational invariance entails that they can only depend on
the functional form of the material subserving this cognition. His advocation of physical
causal closure means that causation runs in only one direction – consciousness has no ex-
planatory role to play in the material world. Finally, the demand for simple, elegant laws
means that he must locate some fundamental building block on which his theory may be
built.
An obvious candidate for this primary element is information. Chalmers explains the no-
tion of an information space at some length (277–280) – the core idea is that “information is a
difference that makes a difference” (281) and that “information is as information does” (282).
The skeleton theory he arrives at is as follows (286):
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