What is Life? Some Perspectives
What is Life? Life seems to be one of those things that we all know more or less what it is but seem quite at a loss to define it. A quick look at the definition in the Oxford English Dictionary seems to back up this statement. “Life — The condition or attribute of being alive; animate existence; Opposed to death.” While we recognize that sometimes it is hard to know for sure if something is alive (a coral, a virus, an animal or plant near death), we generally are quite confident in our judgments of the presence of life. One of the reasons for this “feeling for life” is that we ourselves are living beings. We experience ourselves as living unities in relation to an environment. We feel a kinship with other living things and dread the loss of life, which we call death. Because life is the basic fact and condition of our being human, we also use the word in many metaphorical and analogical senses to describe the exuberance that we feel about many things. This exuberance can vary from the mundane, “She was the life of the party,” to our deepest religious experiences, “I am the resurrection and the Life [John 10:24].” But while life seems to evade simple definition, it is clearly something that can be studied through the methodologies of the physical and life sciences, primarily biology and chemistry. This study already has its roots in pre-Christian times (think of Aristotle’s writings on biology) but has seen its greatest flowering in the last one hundred years with developments in physiology, genetics, biochemistry, and molecular biology. Biologists and those in related disciplines are gradually teasing out the mechanisms and processes by which life differs from nonlife. Many in the biological community would argue that the question “what is life?” is simply a biological question for which we either already have or soon will have rather complete answers. What possibly can the philosopher bring to the discussion? To ask this question dredges up a whole raft of questions upon which there is little consensus. It involves the classical philosophical questions of the possibility of human knowing and the nature of human knowledge. More recently, such questions have re¬emerged in the somewhat different context of the philosophy of science. What are the goals of the physical and life sciences? What does science have to tell us? Does science in some sense describe the “real world”? And finally, what is the relationship of philosophy to science? Is philosophy primarily a way to tidy up scientific statements and language, as some of the earlier analytic philosophers would seem to suggest? Or does philosophy provide a sort of “separate window” on the world, which can then be brought into dialogue with the results of the physical and life sciences? In the course of this paper, some of these questions will be dealt with in at least an indirect manner. However, it is not my intention to spell out a full philosophy of science or philosophy of biology. To clarify matters, let me make some comments on my personal philosophical starting point. These points will be made with minimal argumentation. For those interested in the background I would suggest consulting the author who has had the greatest impact on my own thinking, Bernard Lonergan. For my own slant on Lonergan’s thought and especially on how it relates to problems in the contemporary physical and life sciences, you may wish to consult my own papers listed in the footnotes. (1) Both the physical and life sciences and philosophy are, in a generalized sense, empirical. Both science and philosophy begin with experience. Philosophy begins with the experience of the human person in the process of knowing and deciding. Science begins with either the direct or indirect experience of the material things that science studies. (2) This experience of either myself or the things around me is only the first component of human knowledge. Knowledge implies further questions coming out of that experience and the answering of those questions in a reasonable and coherent way. A true increment in knowledge is had only when the adequacy of those answers is confirmed in judgment. Knowledge implies a triple cord — experience, understanding, and judgment. (3) The special role of philosophy, especially in relation to the sciences, is to experience ourselves as knowers, to understand ourselves as knowers, and finally to judge whether our understanding of ourselves as knowers is correct or incorrect. In this sense, philosophy has its own role, one that cannot be simply subsumed under the sciences. It is not because philosophy gives us some “superview,” but because philosophy examines human knowing and, for better or worse, knowing is the only way we know things. (4) So far so good. What we have said seems reasonable and would even have its points of contact with later linguistic philosophy.4 There is, however, a further step, which is clearly more difficult. Does the nature of human knowing tell us anything about the nature of what is known? Kant’s preliminary answer was “yes,” but then he realized that the a priori categories fatally prejudiced the possibility of true knowledge. All we can know with certitude is the phenomenal world; the deeper noumenal world remains, at best, obscure. Lonergan’s answer to the same question is a clear, but limited affirmative. The structure of human knowing reveals something about the structure of the real. This is not the place to unpack this assertion. But let me give an example by which everyday science makes the same kind of assertion; the way we ask questions already tells us something about the way we presume things really are. When I teach elementary quantum mechanics, I tell my students that the time-dependent wave function describing a particle is a function of space and time, in one dimension we write y = y(x, t). Why a function of x and t? Maybe another choice of variables would be better? OK, check it out. But why use a functional relationship at all? I would suggest that it is because the things that physics studies are intelligibly related and that mathematical functions are a good way to represent those intelligibilities. (We could conceivably use geometry the way poor Galileo did before the development of algebra. But most would argue that there is an intelligible isomorphism between the geometric and algebraic ways of expressing the relationships.) Some philosophers of science would suggest that this is the reason why a denial of scientific realism is the only course. I would suggest, and I think most scientists would agree, that we are justified in presuming intelligible relationships at least between some variables. In other words, we make presumptions about the nature of reality based on the way we know. Lonergan describes this isomorphism between cognitional structures and the object of our knowing in terms of “heuristic structures.” The nature of human cognition tells us something about the nature of what is known. (5) If knowing is all we have, then we should be very careful to limit Our knowledge to what we can know — nothing more and nothing less. Knowing reality is about experience, understanding, and judgment. Lonergan’s nemesis is that most of us tend to truncate our knowing to the level of experience. Or to put it in other terms, we make the criterion of reality our ability to imagine it or what we might call a “hard sense of reality.” Our knowledge begins with experience, but the real is ultimately verified intelligibility. Enough of this for now, let’s get back to the question of this paper, “What is life? — Current scientific and philosophical perspectives.” 2. LIFE FROM THE POINT OF VIEW OF THE LIFE SCIENCES The life sciences obviously have a great deal to tell us about the particulars of living systems, but what do they have to tell us about the more general question, “what is life?” In general the life sciences have been extremely successful in explaining more complex entities in terms of what are usually referred to as more basic entities. Thus the macroscopic phenomenon of reproductive inheritance is explained in terms of the laws of genetics and basic units referred to as genes, which in turn are explained by the chemistry of DNA and associated molecules, which is explained in terms of the chemistry of large polymers, and so down the line. Erwin Schrodinger in his 1944 classic What Is Life? stated the basic presupposition of many scientists very clearly, How can the events in space and time, which take place within the spatial boundary of a living organism, be accounted for by physics and chemistry? The preliminary answer, which this book will endeavor to expound and establish, can be summarized as follows: The obvious inability of present-day physics and chemistry to account for such events is no reason at all for doubting that they can be accounted for by those sciences. Schrodinger wrote this statement in 1944 before the discovery of the structure of DNA and the many subsequent advances in molecular biology and biochemistry. Sixty years later one would be hard pressed to deny the chemical and physical basis of all living systems. But is biology just chemistry? Is there something about life that goes beyond the chemistry? Most biologists and biochemists would probably argue for some variety of physicalism. Physicalism claims that all living things are physical objects. If you take an organism, no matter how complex, and break it down into its constituents, you will find matter and only matter there. Living things are made of the same basic ingredients as non-living things. The difference is in how those basic ingredients are put together. The physicalist stance is usually contrasted with what is called. vitalism. Definitions of vitalism vary, but in general they argue that living beings require something more than just the right combination of molecules and atoms.? Henri Bergson referred to this something more as the élan vital, a “vital force” responsible for the dynamism seen in evolution.8 We will later comment further on the physicalist-vitalist dichotomy. However, as mentioned above, most biologists would argue for the physicalist account of life. But all would agree that there are problems. One way to approach these problems is to ask a simple question. If biology is really just chemistry and physics, then can all biology be fully explained in chemical or physical terms? This is the so-called problem of epistemological reductionism. Can statements made in the science of biology — physiological explanations, evolutionary theory, ecology, whatever — be fully reduced to statements in chemistry or physics? In some cases it may be true that a biological explanation is fully reducible to a chemical or physical explanation. For example, such and such an illness is always due to a defective gene at such and such a position in the DNA of the human person. However, most situations are not so simple. Take for example the concept of evolutionary fitness.9 The particular biological and chemical trait that makes for fitness in one organism will be very different from that in another organism. And even the same organism, under different environmental pressures, may have a different genetic makeup that we would describe as fit. Clearly there is no one-to-one mapping from biology to chemistry to physics. Examples could be multiplied at will. This situation is logically referred to as supervenience. Supervenience implies a nonsymmetric hierarchy of explanation. Properties at the lower level are presumed to determine the higher-level properties, but not viceversa. Higher-level properties do not determine lower-level properties in a deterministic way. A certain genetic trait, with its corresponding physical trait, determines the fitness of a particular animal. However, the biological trait of fitness can be embodied in innumerable ways in various animals and in various environments.10 Supervenience allows a more nuanced understanding of physicalism and also indicates why the higher-level sciences such as biology or psychology are important, even in an essentially reductionistic account of living things. The well-known theologian Nancey Murphy argues that the concept of supervenience allows for a “non-reductive physicalism.” Her main concern is whether the human mental states can simply be reduced to neurobiology. However, similar arguments would hold for the relationship of biology to chemistry or chemistry to physics.11 As a logical concept that helps clarify explanatory relationships at various levels, it seems uncontroversial. Whether it can bear the weight of allowing a truly “nonreductive” physicalism when considering the relationship between conscious states and the neurological substrate or between living and nonliving things is a more controversial question.12 The question of what is the “something more” that distinguishes life from nonlife (or more importantly for us, the human from other animals) will not go away. The problem with vitalism is that it seems too much like a magic something added to a chemical system to make it come alive. Biologists are slow to accept it, because it seems almost by definition to be outside the gamut of their investigation. A concept that is used with increasing frequency in theoretical biology and in philosophy is that of emergence. It is a slippery concept, but its proponents want to recognize that there are really new things that emerge without denying the physical and chemical basis of living things and of human persons.13 The root of the concept of emergence is the perceived complexity of the universe we inhabit. Complex things exist that are on the one hand based on lower-level things (molecules are made of atoms) but at the same time involve a clearly defined subset of all possible variations at the lower level. This rule of limitation is described by Harold Morowitz as a “pruning rule” or “pruning algorithm.” The most commonly given example of this pruning algorithm is the Pauli principle which allows the emergence of the periodic table and chemistry from a much larger possible range of subatomic entities.14 It is suggested that the emergence of life must involve similar pruning algorithms. What constrains the chemistry in a living cell such that only a certain subset of possible chemical behaviors are present in living systems?15 On a physicalist understanding, emergence would seem to simply point to the appearance of new entities through a rearrangement of the component parts. These new entities are explained by concepts that supervene on lower levels of explanation. Molecules are a certain. arrangement of atoms that allow a new class of entities to be studied. This new emergent science (chemistry) has many explanatory concepts that do not simply correspond one-on-one with the concepts of atomic physics. Chemical concepts such as valence, reactivity, and isomerism supervene on the lower-level atomic and physical concepts. However, on this understanding of emergence, ontological priority is still given to the smallest element. Many, though not all, would presume that the lower levels completely determine the higher-level emergent properties. There are problems with this simple physicalist understanding of emergence. One problem is “Where to put the pruning algorithm?” To what level should we assign the capacities that allow integration at a higher level — to the lower level or the higher level? For example, the Pauli principle is often cited as the principle that allows the emergence of the periodic table, which is basic to chemistry and ultimately biology. Does the need to deal with higher-level entities lead to an “enlargement of the lower-level science?”16 Is the Pauli principle, which allows the formation of atoms, a basic property of subatomic matter or an emergent property of chemical systems? The position argued in this paper is that (a) there are truly emergent properties that can only be understood at the higher level of integration and (b) to learn at what level a certain scientific principle is active is primarily a question for science to determine. There are also emergent phenomena that seem difficult to understand in the pure physicalist framework — life on the level of organism and cognition and consciousness on the level of the human person. Terrence Deacon, a physical anthropologist now at Berkeley, is concerned with the development of the human mind.17 He argues for three categories of emergence.18 The first level involves the emergence of higher-order collective properties, which can be explained in terms of the component parts. Using statistical thermodynamics, the properties of liquid water can be explained in terms of the collective properties of the water molecules. Second-order emergence adds in a feedback mechanism that will amplify certain properties and diminish others. Oscillating chemical reactions and developments studied in chaos theory would come under this rubric. First-order emergence is essentially independent of time. In second-order emergence, the emergent properties are a function of time and in more complex (chaotic) systems, the longer the period of time, the less the possibility of predicting future states of the system. The third category of emergence adds development and/or evolution to the second category. Information at one level of development is “remembered” and acted upon in such a way that it may either be amplified or lost, with the resulting divergence of new types of entities. Evolution is the primary example of third-order emergence. Because of the global nature of the evolutionary process, except in very controlled experiments, it will be impossible to predict the products of third-category emergence. As is often noted, neo¬Darwinian evolutionary theory is explanatory but in most cases not predictive. This is in contrast to the properties of liquid water, which can, in principle, be determined from a study of the collective properties of H2O molecules. So what is life? As suggested above, this is primarily a scientific question. First of all, essentially all scientists would agree that it is the result of an extremely complex process, what we might call layered third-category emergence. And what are the unique properties of living systems as opposed to other complex systems? This again is a scientific question. Schrodinger in his 1944 lectures stressed the order that is maintained in living organisms despite the randomness of physical processes. He had only vague hints of DNA and RNA and so suggested a-periodic crystal structures as the basis of the stability and evolutionary development of living things. His lectures are an amazing, if still vague, prediction of what molecular biology would bring to light during the second half of the twentieth century and right up until our own time. Beyond the tension between stability and the possibility of evolutionary development, organisms require an energy-processing mechanism. This is usually referred to as metabolism. For essentially all living systems, bacteria to human beings, the key molecule in this complex process is usually identified by a three-letter acronym — ATP (adenosine triphosphate). But just as DNA by itself explains very little but is at the heart of a very complex web of chemical reactions, so ATP is at the heart of the complex chemical processes usually referred to as the “metabolic pathways.”19 Stuart Kaufmann, a • theoretical biologist and complexity theorist, while recognizing the tremendous strides that have been made in biochemistry and molecular biology, argues that a real answer to the question “what is life?” still alludes us. Kaufmann understands living things as “autonomous agents.” “An autonomous agent must be an autocatalytic system able to reproduce and to perform one or more thermodynamic work cycles.”20 The definition essentially retains the two key notions in the above paragraphs, reproduction and metabolism. But to this it adds the concept of “autonomous agent.” There is a certain “selfness” in any living thing. Living things are unities that are somehow separated from their environments and can thus develop in unique ways. Kaufmann then asks if there are laws for the emergence and evolution of biological systems, somehow analogous to the Pauli principle in chemistry. In his most recent book he suggest four candidate laws for the construction of a biosphere.21 We will not review these suggestions here, but only note that they are attempts to understand the constraints (pruning algorithms) that allow the emergence of living things from their chemical precursors. 3. WHAT DOES PHILOSOPHY HAVE TO TELL US? So far much of what we have said seems to be more science than philosophy, even if it is not the detailed science that is moving forward in laboratories all over the world. The title of this paper suggests that we consider philosophical as well as scientific perspectives. I suggested earlier that at least one of the purposes of philosophy was to consider the very process by which we can know anything at all —DNA, ATP, autonomous agents, and so forth. Is any of this stuff really true? How do we know it is? There are many good philosophers who would deny the possibility of really knowing the truth of modern biology. They doubt not only the possibility of knowing whether current theories are true, but even the possibility of there being any kind of process by which incorrect or incomplete understandings can be improved upon. Given this situation, can philosophy give us some clue about what we can know and what we can’t? Many of those with a scientific bent have argued that sense knowledge is the one thing that is common to all of us — if we can all agree on certain sensible phenomena there is some hope of saving objectivity. The problem, of course, is that science, whether physics, chemistry, or molecular biology, is not just about sense knowledge but also about very complex understandings and equally complex ways of verifying these understandings. Here I now return to the five points I made at the beginning of the article, which outlined my personal philosophical starting point. Knowledge is based on the triple cord of experience (both experience of the “outside” world and experience of myself), understanding that experience, and finally judging the adequacy of that understanding. Each level calls forth the next. The process of knowing is all we have, and we affirm it even when denying the possibility of knowledge. For even the most adamant relativist will argue that his particular understanding of the nature of reality is somehow verifiable. Science is an extremely complex web of knowledge where much of what we know is dependent on other areas of science. This weblike nature of scientific knowing imparts a tentativeness to scientific knowing that is not present in commonsense knowing. However, when all is said and done, science does tell us something about the real world. During the last fifty years humankind has gained real knowledge of the mechanism of living things. But what does it mean to say that I know something? Does it mean that we have a picture, something like a photograph? Does it mean that we use some kind of inner model to correlate various sense impressions? Lonergan’s work reveals that when we say we know something about subatomic particles, quarks, strings, atoms, molecules, metabolic pathways, and other objects of scientific knowledge, we are simply answering questions and then doing our best to verify that those answers are correct. In saying this we are broaching a topic, which sets Lonergan’s thought apart from our normal intuitive feelings about knowing. Because all of our knowing begins from experience, we tend to make experience —a sense of hardness or imaginability — the criterion of reality. But what scientific practice reveals is that the criterion of reality is verified intelligibility, nothing more and nothing less. Now what does this have to do with biology? If the imaginability of certain objects of knowledge is the criterion of their reality, then the smallest pieces will have ontological priority. A next step is often to presume that these smallest components (quarks, strings, or whatever) completely determine the reality of larger things. We are left with a strong mechanistic determinism.23 Ontological priority is given to the smallest chunks of matter, which determine the nature of all complex systems. This kind of thinking is behind the “physical monism” that is presumed by most to be implied by contemporary physics, chemistry and biology. But what is the alternative? Who could deny that physics is the basis of chemistry and that chemistry is the basis of biology and that biology is the basis of human psychology? Are we to return to vitalism, the idea that “something new” is added for life to emerge from nonlife or for the human person to emerge from the biological matrix? To answer this question we must ask about the nature of the tiered levels of reality that are the objects of our science. As argued above, all knowing, at least in the universe in which we live, involves a triple cord: experience, understanding, and judgment. We experience data, whether its size, shape, weight, color, and so forth. From this experience we seek to gain understanding. We may seek to understand the way things operate, either in an explanatory mode (things in relation to each other), or in a descriptive mode (things in relation to us). In the explanatory mode, we are ultimately seeking to understand the basic laws of physics, chemistry, biology and so on. We also attempt to understand things — unity, identity, wholes such as atoms, molecules, living organisms, or human persons, which we experience and ultimately understand in their oneness. Finally, we may attempt to understand the complex arrangements of things in both space and time — what Lonergan refers to as “schemes of recurrence.” Such schemes of recurrence would include everything from our solar system, to social and economic systems, to the complex artifacts of human ingenuity. However, not all understandings are correct, Whether of scientific laws, our understanding of the nature of the things that make up our universe, or complex schemes of recurrence. Ultimately our knowing requires verification in judgment. To describe the properties of things and events, Lonergan uses the technical term “conjugates.” “Experiential conjugates are correlatives whose meaning is expressed, at least in the last analysis, by appealing to the content of some human experience.”24 Colors and tastes, as well as the categories of descriptive science, such as anatomy or geology, are examples of descriptive conjugates. “Pure (or explanatory) conjugates, on the other hand, are correlatives defined implicitly by empirically established correlations, functions, laws, theories, systems.”25 Explanatory conjugates, since they involve things in relation to each other, are implicitly defined by the equations and explanatory networks of the sciences. Lonergan defines the notion of a thing “as an intelligible, concrete unity differentiated by experiential and explanatory conjugates.”26 Things exist on various levels and are the unities, which are explained —subatomic particles, atoms, molecules, cellular organisms, sensitive organisms, human persons that can transcend themselves in knowing and loving. Science knows each level through the descriptive and explanatory conjugates correlative to the thing under study. The criterion of reality of both conjugates and things is simply their verified intelligibility. Each level of reality has its own set of explanatory conjugates, which are the particular subject of the science of that level — physics, chemistry, biology, sensitive psychology, and so forth. No set of conjugates or any level of things is more real than any other. The real is verified intelligibility at whatever level one is operating. Having said that each level is equally real is not to deny the clearly verified conclusion of levels of reality. At each level the random conjugates of the lower level are unified in a higher integration. Chemistry systematizes what would be merely coincidental events on the atomic level allowing the emergence of an autonomous science of chemistry. Biology is an autonomous science integrating what would be merely coincidental events on the level of chemistry. The integration of coincidental manifolds at a new level does not take away the autonomy of the lower levels. The reality of the biological organism includes the conjugates of chemistry and physics. Because of this, the most exciting areas of science will be the cross disciplinary areas — molecular biology, chemical physics, and so forth. Here science attempts to understand how those lower-level conjugates are systematized at the new level. As noted above, a thing for Lonergan is an “intelligible, concrete unity differentiated by experiential and explanatory conjugates.”27 Experiential conjugates refer to the properties of the thing in relation to the knower, while explanatory conjugates refer to properties implicitly defined by scientific laws and correlations, which consider things in relation to things. Lonergan then makes use of the traditional categories of potency, form and act. In keeping with Lonergan’s starting point of cognitional analysis, these three are related to each other, as are experience, understanding, and judgment. Thus central form refers to the intelligible unity of a given thing, while conjugate form refers to the intelligibility of its properties (that is, conjugates). Central and conjugate acts refer to the in-principle verifiable existence of the thing itself (central act) or of the properties of the thing (conjugate act). With these definitions we are now ready to define “emergence.” Lonergan defines emergence as the process by which “otherwise coincidental manifolds of lower conjugate acts invite the higher integration effected by higher conjugate forms.”28 For example, on the level of subatomic physics there exist things such as protons, electrons, and neutrons. Lower conjugate acts here refer to the existing properties of these things on this level. These conjugate acts are intelligible, and this intelligibility is in accord with what Lonergan describes as both classical and statistical laws of physics. However, there exists a basic randomness, which on one level a physicist might describe as a collection of random particles or events, and what Lonergan describes as a “coincidental manifold.” However, given the right set of initial circumstances, in other words, the right probabilities, from this random situation (what Lonergan calls “coincidental manifolds of lower conjugate acts”), there may emerge a higher integration with its own conjugate forms. What is the nature of these emergent entities? Here Lon.ergan distinguishes between two levels — schemes of recurrence and new things. As noted above, schemes of recurrence refer to intelligible systems that circle in on themselves. If A occurs then B occurs, if B occurs then C occurs, and so to the point that A recurs and the circle begins again29. Lonergan likes to use the example of the planetary system. Somehow in the development of our corner of the Milky Way, there emerged a group of planets that orbit around our sun. The recurring pattern of the orbits leads to the emergence of a degree of stability in what otherwise would be random movement. Examples of schemes of recurrence are essentially infinite — from the subatomic through the artifacts of human industry to human society and economics. In the emergence of schemes of recurrence, new conjugate forms will arise. We can describe the mechanics of the solar system, the nature of phase changes in chemistry, the symbiotic relationship of plant species, or the nature of business cycles in economics. Yet, as can be seen from the examples given, schemes of recurrence are ontologically reductive. Given the right circumstances, the classical and statistical laws governing the elements of the scheme will allow us to predict the nature of the scheme of recurrence. But besides the emergence of new schemes of recurrence, there is also the fact of the emergence of truly new things — things now used in Lonergan’s technical sense. As noted above, Lonergan defines the notion of a thing “as an intelligible, concrete unity differentiated by experiential and explanatory conjugates.”3° In what many consider one of Lonergan’s more puzzling chapters, he argues that there are no things within things. This seems to be at odds with atomic and molecular theory of matter, which is now part and parcel of contemporary science. To understand we must return to our understanding of the real as verified intelligibility. An animal is a concrete unit whose basic conjugates are the subject of zoology. The lower-level conjugates of atomic physics (atomic mass and number, electronic structure) are integrated at the new level of chemistry. And the conjugates of chemistry (valence, reactivity, and so forth) are integrated at the level of the biological. Thus an animal, say a rabbit, is a unity in which each of the various levels of matter are integrated to form a unity-identity-whole. On the level of bodies, of course the rabbit has various organs — heart, liver, brain, and so forth — but these are all integrated in one living unity, the rabbit. Terms like respiration and metabolism refer to this the unity-identity-whole that is the particular rabbit. Above I noted that when talking of schemes of recurrence, or more simply when talking of simple aggregates, the new properties (conjugates) that emerge are in principle reducible to the lower-level properties. I can explain the movement of the planetary system solely in terms of the laws of physics. However, when we speak of the emergence of new “things” —atoms, molecules, bacteria, animals, persons — “the higher integration effected by higher conjugate forms” is indicative of a new central form, a new center of intelligibility. 4. WHAT IS LIFE? So what is life? From the point of view of science, we argued that life must involve metabolic processes for the utilization of energy and some form of hereditary reproduction. The organism must also be set apart from the rest of the world, a certain “selfness” for which Stuart Kaufmann coined the term “autonomous agents.” This is not meant to be an exhaustive definition. Other characteristics could be added, for example, a system far from equilibrium, which obtains its sustenance from the environment, or we could add laws similar to those suggested by Kaufmann and alluded to earlier. From the point of view of philosophy, life is a higher integration of chemical conjugates with the corresponding emergence of a new central form and a new unity — the living organism. As a higher integration of chemical conjugates, the laws of chemistry remain in tact. To understand the organism, one has to know chemistry, and for that matter atomic physics and subatomic physics and on down the line. But at the same time the organism is a unity-identity-whole (“unity-idenity-whole” is a technical term in Lonergan, perhaps use hypens.), unifying the chemistry under higher level biological conjugates such as metabolism and reproduction. The nature of these conjugates is a matter for the sciences to explore. Philosophy will not provide a short cut. And where does this put us on the physicalism-vitalism continuum discussed earlier? I would suggest that neither alternative will do. Physicalism, at least in most of its forms, is dependent on what Lonergan calls the myth of “knowing as looking.” For something to be real, beyond the somewhat spartan categories of verified intelligibility, the physicalist adds the criterion that the real must be analogous to the objects of sensation. In this scenario ontological priority is given to the smallest particles — little solid chunks — and the hierarchy of complexity that the sciences reveal is simply due to increasingly complex combinations of the fundamental building blocks. My contention is that at each new level there emerge truly new unities that integrate the lower-level conjugates. Vitalism is mistaken in that it more or less presumes the physicalist interpretation — the real is ultimately comprised of little chunks of matter — and then finds itself at a loss on how to explain living things. So at the last minute an unimaginable “vital force” is added. The suggestion here is that at each level there emerge new unities that integrate the lower level conjugates. The new central form is not an extra something added to a set of lower-level building blocks but rather the central reality of the integrated unit.31 There exist on these various levels different categories of things and these categories imply both experiential and explanatory conjugates at the level at which they are understood. Thus there are the relatively autonomous sciences of subatomic physics, atomic physics, chemistry, biology, and sensitive psychology. At any level, including the macroscopic level of sciences such as physiology and anatomy, the criterion of the real is not ultimately the ability to experience the organism as a unity but to gain verified understanding of the organism as a unity. Having said the above, I should add that there is a sense in which physical monism is correct. Abstaining for the moment on the subject of the human mind and human intentionality, the various levels of things are all material. Their materiality consists not in their ability to be felt or imagined — what does it mean to “feel” a quark or a string? — but in their being individuated objects in space and time.32 The nature of space and time are primarily physical questions currently understood in terms of the theories of special and general relativity. The emergence of a new thing requires a subtle interplay of classical and statistical laws. The term Lonergan uses for this engine of emergence is “emergent probability.” Given the right set of conditions, there will emerge new schemes of recurrence and new things. The only way to understand the details of the process of emergence is to do the interdisciplinary science — in the case of living things, molecular biology is the key to understanding the emergence of life in terms of the chemical conjugates. A question that is often asked is whether scientists will be able to create life forms in the laboratory. My own belief is that sooner or later, scientists will be able to tweak probabilities so that a living thing will emerge from the chemical matrix. This has already been accomplished twice with viruses.33 Scientists still argue whether viruses can be described as living things. They do not seem to fit the definition quoted earlier from Kaufmann above. But they are very close to being living things, and while the simplest bacteria are far more complex, all indications are that sooner or later living things will be “created” in the laboratory from organic starting materials. 5. RELIGION, SCIENCE, AND PHILOSOPHY This paper was originally presented at the conference “Cosmology —Religion and Science in Dialogue.” What does all this have to do with the religion and science dialogue? First, it must be stated that the really key question for the religion-science dialogue is the nature of the human person. All religious traditions are concerned with the human person and his or her relationship with ultimate reality. Believers in the monotheistic traditions share the belief that the human person is created in the image of God. Christians believe that the person Jesus is God incarnate — God among us. In one sense what has been presented here is preparatory for the larger question of the nature of the human person and what is referred to in many religious traditions as the human soul. But to say that this work is preparatory is not to say that it is not important. The human person is also an emergent reality. Just as there is an autonomous science of biology, there also exist autonomous sciences of the human person. But also just as a complete understanding of life must include an understanding of the lower-level conjugates of chemistry and physics, so a complete understanding of the human person requires an understanding of the lower-level biological, chemical, and physical conjugates.34 Thus the answer to the question “what is life?” provides the framework for what Christians would call theological questions. Human persons are part and parcel of the material world. They are emergent entities of this world and not just some sort of spiritual beings acting out their lives on a material stage. Christians believe that God entered this material world in the person of Jesus. As emergent unities — and not just a clever combination of the basic constituents — human persons stand apart and transcend other organisms. As individuals who are capable of knowledge and love, we, are truly “autonomous agents.” Our dignity is to know and love and to be known and be loved as the emergent unities that we are. Frank Budenholzer, SVD First presented at the International Conference on Cosmology: Religion and Science in Dialogue, Fu Jen Catholic University, Hsinchuang, Taiwan, November 26-28, 2004

