Biological Naturalism and Biological RealismConsequently, information theories of consciousness, such as IIT, easily lead to panpsychism
(because almost anything can “carry” information) or at the very least, to ultra-liberal multi-
ple realizability of consciousness (because almost any causally connected system can realize an
amount of integrated information that is above zero). Panpsychism is the idea that each and every
fundamental physical entity is coupled with some kind of elementary mental properties: every-
thing physical has at least a degree of consciousness. Multiple realizability is the idea that the mind
or consciousness has no physical essence, but can be carried by and realized in radically different
types of physical systems (as long as they realize the appropriate abstract patterns of e.g. compu-
tation or information processing). Thus, computers and robots may have consciousness as long
as their processing units carry the appropriate patterns of information for conscious processing.
Information itself is non-material and abstract, but it is easy to confuse its abstractness
with the concrete physical complexity of the physical vehicles that “carry” this information.
Information is easily masquerading as a higher-level physical property, but ontologically it is no
such thing. Information is a second-order, formal property, not a higher-level concrete physical
property. There is no such higher level of physical organization in the brain, where “informa-
tion” emerges out of non-informational physical phenomena, and where this information then
forms the constitutive basis of yet higher physical levels. Because of its abstractness, information
can exist at (or be carried by) any arbitrary physical level. If consciousness consists of informa-
tion, there is nothing particularly biological about the fundamental nature of consciousness.
Informational theories – like their close relatives, functionalist and computationalist theo-
ries – posit an abstract metaphysical domain as being the fundamental ontological nature of
consciousness. Information, causal roles, computations, algorithms: their essence resides in the
world of abstract forms.
But any theory that identifies consciousness with an abstract metaphysical domain “realized”
by concrete physical entities pays a high price. Second-order properties inherit all their causal
powers from their first-order physical realizers; they have no causal powers of their own. Abstract
entities constituted by second-order properties like “information” or “computation” as such
have no causal powers of their own in the physical world; they have no effects on anything; rather it
is the concrete material, physical entities or processes, “realizing” the abstract patterns, that are
causally efficacious (see e.g. Jaegwon Kim’s well-known arguments on this in Kim 1998).
Thus, informational theories have two unacceptable consequences: First, they typically assign
consciousness to all sorts of extremely simple or otherwise unlikely physical systems (such as
photodiodes, bacteria, iPhones, etc.). The empirical evidence and testability for such claims is
nil, and the intuitive plausibility even less. Secondly, they rob consciousness of any causal powers
in the physical realm. If consciousness consists of information or anything else in the abstract
metaphysical domain, it is doomed to be epiphenomenal.
By contrast, the biological approaches BN and BR assign consciousness to the concrete
metaphysical domain of higher-level physical and biological phenomena. Such phenomena have
a concrete spatiotemporal emergent structure and possess concrete causal powers of their own.
The biological approach rejects panpsychism, but allows multiple realizability within narrow
limits. The brains of different animal species can support consciousness although the lower-level
neurophysiological basis may be slightly different.
7 ConclusionsBN and BR argue that consciousness is a higher-level of physical organization in the physi-
cal world, a concrete emergent biological phenomenon that supervenes on lower-level neural
activities in the brain but cannot be reduced to them. Consciousness forms its own level of