Emergence

Emergence is the claim that qualitatively new, even radically novel properties in biological systems and psychological states arise from physical properties governed entirely by the laws of physics. The re-emergence of emergence in the sciences, where whole entities are, or seem to be, more than the sum of all their parts, has been controversial, its assessment ranging from trivial and distracting to radical and revolutionary (Clayton & Davies, 2008). Emergence in the study of consciousness is especially foundational, more as a basic principle undergirding and enhancing various theories than as a specific theory in its own right.

Emergence, according to Paul Davies, means that “at each level of complexity, new and often surprising qualities emerge that cannot, at least in any straightforward manner, be attributed to known properties of the constituents. In some cases, the emergent quality simply makes no sense when applied to the parts. Thus water may be described as wet, but it would be meaningless to ask whether a molecule of H₂O is wet” (Davies, 2008).

Moreover, it could seem astonishing that the properties of two common gases, hydrogen and oxygen, can combine to form a liquid that is wet and a solid that expands when cooled. Yet, physics and physical chemistry can explain all of this in terms of atomic structures and bonding angles.

Emergence and Reductionism

Emergence can be appreciated in contrast with its mortal conceptual rival: reductionism. Reductionism is mainstream science, the bedrock assumption of the scientific method: all, in principle, can be explained by physics, even if all, in practice, cannot be.

Davies defines “ontological reductionism” as the state of affairs where all reality “is, in the final analysis, nothing but the sum of the parts, and that the formulation of concepts, theories, and experimental procedures in terms of higher-level concepts is merely a convenience.” (He distinguishes “methodological reductionism,” where reductionism is a “fruitful methodology,” from “epistemological reductionism,” where all we can know is that reductionism works by explaining one scientific level in terms of lower or more fundamental levels, without making any claim on ultimate reality.) (Davies, 2008).

But “for emergence to be accepted as more than a methodological convenience—that is, for emergence to make a difference in our understanding of how the world works,” Davies argues that “something has to give within existing theory.” Davies himself has been a leader in “a growing band of scientists who are pushing at the straitjacket of orthodox causation to 'make room' for strong emergence (see below), and although physics remains deeply reductionistic, there is a sense that the subject is poised for a dramatic paradigm shift in this regard” (Davies, 2008).

Weak and Strong Emergence

To make sense of emergence, we distinguish between its “weak” and “strong” forms. In its weak form, while it may not be apparent how the properties of one level can be entirely explained by the properties of a lower, more fundamental level, in principle, they can be explained, and ultimately, science will advance to explain them.

In its strong form, properties at one level can never be explained in terms of properties of lower levels, not even in principle, no matter how ultimate the science. As Davies explains, “Strong emergence is a far more contentious position, in which it is asserted that the micro-level principles are quite simply inadequate to account for the system's behaviour as a whole. Strong emergence cannot succeed in systems that are causally closed at the microscopic level, because there is no room for additional principles to operate that are not already implicit in the lower-level rules.”

He posits only three “loopholes”: the universe is an open system, non-deterministic quantum mechanics, and computational imprecision at fundamental levels—all three have obvious problems, which is why they are “considered unorthodox departures from standard physical theory” (Davies, 2008).

David Chalmers says that “a high-level phenomenon is strongly emergent with respect to a low-level domain when the high-level phenomenon arises from the low-level domain, but truths concerning that phenomenon are not deducible even in principle from truths in the low-level domain.”

He distinguishes a high-level phenomenon that is “weakly emergent with respect to a low-level domain when the high-level phenomenon arises from the low-level domain, but truths concerning that phenomenon are unexpected given the principles governing the low-level domain” (Chalmers, 2008).

Consciousness and Strong Emergence

Strong emergence, Chalmers contends, has “radical consequences,” such that “If there are phenomena that are strongly emergent with respect to the domain of physics, then our conception of nature needs to be expanded to accommodate them. That is, if there are phenomena whose existence is not deducible from the facts about the exact distribution of particles and fields throughout space and time (along with other laws of physics), then this suggests that new fundamental laws of nature are needed to explain these phenomena” (Chalmers, 2008).

By contrasting strong and weak emergence, Chalmers sets the stage to enact the grand epic of consciousness. “In a way, the philosophical morals of strong emergence and weak emergence are diametrically opposed. Strong emergence, if it exists, can be used to reject the physicalist picture of the world as fundamentally incomplete. By contrast, weak emergence can be used to support the physicalist picture of the world, by showing how all sorts of phenomena that might seem novel and irreducible at first sight can nevertheless be grounded in underlying simple laws” (Chalmers, 2008).

Chalmers is not shy: “I think there is exactly one clear case of a strongly emergent phenomenon, and that is the phenomenon of consciousness.” He suggests that “the lawful connection between physical processes and consciousness is not itself derivable from the laws of physics but is instead a further basic law or laws of its own. The laws that express the connection between physical processes and consciousness are what we might call fundamental psychophysical laws” (Chalmers, 2008).

The challenge of strong emergence, especially in consciousness, is a deep probe of not only how the mind works but also how the world works. Its influence is felt all along the Landscape of Consciousness.