By the end of the modern period, a particular world view had become firmly entrenched in the public understanding. Unlike most philosophical positions, which are sharply distinguished from scientific theories, this world view was widely seen as a direct implication of science, and even as the sine qua non for all scientific activity. For shorthand, let's call this view “materialism.”

Materialism consisted of five central theses:

1. Matter is the fundamental constituent of the natural world.

2. Forces act on matter.

3. The fundamental material particles or “atoms” – together with the fundamental physical forces, whatever they turn out to be – determine the motion of all objects in nature. Thus materialism entails determinism.

4. All more complex objects that we encounter in the natural world are aggregates of these fundamental particles, and their motions and behaviors can ultimately be understood in terms of the fundamental physical forces acting on them. Nothing exists that is not the product of these same particles and forces. In particular, there are no uniquely biological forces (vitalism or “entelechies”), no conscious forces (dualism), and no divine forces (what came to be known as supernaturalism). Thus materialism implied the exclusion of dualism, downward causation (Bøgh Andersen et al., 2000), and divine activity.

5. Materialism is an ontological position, as it specifies what kinds of things do and do not exist. But it can also become a thesis concerning what may and may not count as a scientific explanation. When combined with a commitment to scientific reduction, for example, it entails that all scientific explanations should ultimately be reducible to the explanations of fundamental physics. Any other science, say biology or psychology, is incomplete until we uncover the laws that link its phenomena with physics. In its reductionist form – which historically has been its most typical form – materialism thus excludes interpretations of science that allow for “top-down” causation, also known as “strong emergence.” Materialists may be divided on whether, and if so how soon, these reductions will actually be accomplished. Still, it is an entailment of materialism in most of its modern forms that an omniscient knower would be able to reduce all higher-order phenomena to the locations and momentums of fundamental particles.

Ever since the elucidation of the molecular basis of living systems, we have known that all elementary processes of life are governed by information. Thus, information turns out to be a key concept in understanding living matter (Küppers, 1990). More than that: the flow of information at all levels of the living system reveals the properties of communication. This means that the information stored in the genome of the organism is expressed in innumerable feedback loops – a process through which the genetic information is continually re-evaluated by permanent interactions with the physical environment to which it is exposed. In this way, the living organism is built up, step by step, into a hierarchically organized network of unmatched complexity.

The fact that all phenomena of life are based upon information and communication is indeed the principal characteristic of living matter. Without the perpetual exchange of information at all levels of organization, no functional order in the living organism could be sustained. The processes of life would implode into a jumble of chaos if they were not perpetually stabilized by information and communication. In this chapter, I should like to consider some of the consequences that follow from this for our philosophical understanding of reality.

Scientists who speculate on philosophical questions usually agree that classical materialism – the view that reality consists of nothing but small massy particles bumping into one another in an absolute and unique space–time – is intellectually dead. Accounts of the universe now regularly involve notions such as that of manifold space–times, quantum realities that exist at a more ultimate level than, and are very different from, massy particles in one specific space, and informational codes that contain instructions for building complex integrated structures displaying new sorts of emergent property.

What this suggests is that the nature of the reality investigated by physics and biology is much more complex and mysterious than some Newtonian materialists thought (though of course Newton himself was as far from being a materialist as one can get). In particular, the role of information in any account of our universe has come to take on a new importance.

A host of surveys indicate that what Christians, and indeed other religious believers, today affirm as ‘real’ fails to generate any conviction among many of those who seek spiritual insight and who continue regretfully as wistful agnostics in relation to the formulations of traditional religions – notably Christianity in Europe, and in intellectual circles in the USA. Many factors contribute to this state of affairs, but one of these, I would suggest, is that the traditional language in which much Christian theology, certainly in its Western form, has been and is cast is so saturated with terms that have a supernatural reference and colour that a culture accustomed to think in naturalistic terms, conditioned by the power and prestige of the natural sciences, finds it increasingly difficult to attribute any plausibility to it. Be that as it may, there is clearly a pressing need to describe the realities that Christian belief wishes to articulate in terms that can make sense to that culture without reducing its content to insignificance.

Correspondingly, there is also a perennial pressure, even among those not given to any form of traditional religiosity, to integrate the understandings of the natural world afforded by the sciences with very real, ‘spiritual’ experiences, which include interactions with other people and awareness of the transcendent.

Copenhagen is the perfect setting for our discussion of matter and information. We have been charged ‘to explore the current concept of matter from scientific, philosophical, and theological perspectives’. The essential foundation for this work is the output of the intense intellectual struggles that took place here in Copenhagen during the twenties, principally between Niels Bohr, Werner Heisenberg, and Wolfgang Pauli. Those struggles replaced the then-prevailing Newtonian idea of matter as ‘solid, massy, hard, impenetrable, moveable particles’ with a new concept that allowed, and in fact demanded, entry into the laws governing the motion of matter of the consequences of decisions made by human subjects. This change in the laws swept away the meaningless billiard-ball universe, and replaced it with a universe in which we human beings, by means of our intentional effort, can make a difference in how the ‘matter’ in our bodies behaves.

The role of mind in nature

Unfortunately, most of the prevailing descriptions of quantum theory tend to emphasize puzzles and paradoxes in a way that makes philosophers, theologians, and even non-physicist scientists leery of actually using in any deep way the profound changes in our understanding of human beings in nature wrought by the quantum revolution. Yet, properly presented, quantum mechanics is thoroughly in line with our deep human intuitions. It is the 300 years of indoctrination with basically false ideas about how nature works that now makes puzzling a process that is completely in line with normal human intuition. I therefore begin with a non-paradox-laden description of the quantum universe and the place of our minds within it.

The matter concept has had an extraordinarily complex history, dating back to the earliest days of the sort of reflective thought that came to be called ‘philosophy’. History here, as elsewhere, offers a valuable means of understanding the present, so it is with history that I will be concerned – history necessarily compressed into simplified outline.

This story, like that of Caesar's Gaul, falls readily into three parts. First is the gradual emergence in early Greek thought of a factor indispensable to the discussion of the changing world and the progressive elaboration of that factor (or, more exactly, cluster of factors) as philosophic reflection deepened and divided. Second is the radical shift that occurred in the seventeenth century as the concept of matter took on new meanings, gave its name to the emerging philosophy of materialism and yielded place to a derivative concept, mass, in the fast-developing new science of mechanics. Third is the further transformation of the concept in the twentieth century in the light of the dramatic changes brought about by the three radically new theories in physics: relativity, quantum mechanics, and expanding-universe cosmology, with which that century will always be associated. Matter began to be dematerialized, as it were, as matter and energy were brought into some sort of equivalence, and the imagination-friendly particles of the earlier mechanics yielded way to the ghostly realities of quantum theory that are neither here nor there.

The term “information” has become nearly omnipresent in modern biology (and medicine). One would probably not exaggerate if the famous saying of evolutionary biologist Theodosius Dobhzhansky, that “nothing in biology makes sense except in the light of evolution” should nowadays be reframed as “nothing in biology makes sense except in the light of information.” But are those two concepts, evolution and information, somehow internally related? And if so, how?

Information in evolution

In textbooks, newspapers, and even scientific papers, the meanings of the terms “evolution” and “information” are generally supposed to be well known, and they are rarely explained. And yet, there is no general consensus in science, or even in biology, about what they really mean. For instance, the preferred exemplar (in the Kuhnian sense) of evolution by natural selection is that of industrial melanism. In woodlands, where industrial pollution has killed the lichens and exposed the dark brown tree trunks, dark forms of the peppered moth – melanics – are supposedly better camouflaged against predation from birds than are the light gray forms that predominated before the Industrial Revolution. The observation by 1950 that darker forms had largely displaced lighter forms was thus taken as evidence for natural selection in action. This exemplar does indeed illustrate the effect of natural selection, but whether it shows evolution depends on your idea of evolution. Thus, if by the term “evolution” is meant something like “the origin of species,” then it is remarkable that no speciation has actually taken place here, and it is not obvious that any speciation would indeed occur in a case like this. So, populations do indeed change as a result of natural selection, but is this mechanism also behind speciation and evolution at large? The majority of biologists certainly feel assured that macroevolution – that is, evolution above the level of species – is in fact the tardy result of an infinitely ongoing microevolution (adaptation in populations), but there remains serious disagreement on this (Depew and Weber, 1995; Gould, 2002).

“I refute it thus!” Samuel Johnson famously dismissed Bishop George Berkeley's argument for the unreality of matter by kicking a large stone (Boswell, 1823). In the light of modern physics, however, Johnson's simple reasoning evaporates. Apparently solid matter is revealed, on closer inspection, to be almost all empty space, and the particles of which matter is composed are themselves ghostly patterns of quantum energy, mere excitations of invisible quantum fields, or possibly vibrating loops of string living in a ten-dimensional space–time (Greene, 1999). The history of physics is one of successive abstractions from daily experience and common sense, into a counterintuitive realm of mathematical forms and relationships, with a link to the stark sense data of human observation that is long and often tortuous. Yet at the end of the day, science is empirical, and our finest theories must be grounded, somehow, “in reality.” But where is reality? Is it in acts of observation of the world made by human and possibly non-human observers? In records stored in computer or laboratory notebooks? In some objective world “out there”? Or in a more abstract location?

The ground of reality

When a physicist performs an experiment, he or she interrogates nature and receives a response that, ultimately, is in the form of discrete bits of information (think of “yes” or “no” binary answers to specific questions), the discreteness implied by the underlying quantum nature of the universe (Zeilinger, 2004). Does reality then lie in the string of bits that come back from the set of all observations and experiments – a dry sequence of ones and zeros? Do these observations merely transfer really-existing bits of information from an external world reality to the minds of observers, or are the bits of information created by the very act of observation/experiment? And – the question to which this entire discussion is directed – are bits of “classical” information the only sort of information that count in the reality game, or does an altogether different form of information underpin reality? In short, where is the ontological ground on which our impression of a really-existing universe rests?