Chapter 3 Chapter 2 The Status of Biology in Science and Its Conceptual Structure-2

Questions such as why some objects in nature are animate and others are inanimate, and what characteristics biological organisms have, have long been raised by the ancients.From the Epicureans and Aristotle until the early part of this century there have been two opposing interpretations of the phenomenon of life.According to the mechanistic school, organisms are nothing but mechanical devices whose operation can be explained by the laws of mechanics, physics and chemistry.The little mechanists of the seventeenth and eighteenth centuries saw no significant difference between a rock and a living organism.Don't they all have the same properties—gravity, inertia, temperature, etc., and obey the same laws of physics?When Newton proposed the law of gravitation in a purely mathematical way, many of his followers assumed that there was an invisible but strict material gravitation to explain the motion of planets and the gravitation of the earth.Some biologists at that time also blindly invoked an equally material and equally invisible force (vitality) to explain life activities.

But later scholars believe that such a vitality is beyond the laws of chemical physics.They thus followed the tradition that began with Aristotle and other ancient philosophers.This school of vitalism, in contrast to the mechanistic school, holds that some processes in living organisms do not obey the laws of chemistry and physics.Vitalism continued to have representatives well into the 20th century, the last of which was the embryologist Hans Driesch.But by the 1920s and 1930s biologists almost universally rejected vitalism for two main reasons.First, because vitalism relies on an unknown, or even unknowable, motive force, and thus is practically outside the realm of science; According to the author, these phenomena "require" a vitalistic explanation.It is fair to say that for more than fifty years biologists have considered vitalism to be a dead thing.It is strange that some physicists and philosophers still cling to it during this time.

The rejection of vitalism was possible because of the simultaneous rejection of the vulgar notion that animals are nothing but machines.Like Kant in his later years, most biologists recognized that living things and non-living things are different, and that the difference cannot be explained by assuming a certain vitality, but by a radical revision of the mechanistic doctrine.Such a new theory must first admit that none of the functions, processes, and activities of biological organisms is in conflict with or independent of the laws of physics and chemistry.All biologists are thorough "materialists", that is to say they do not recognize supernatural or immaterial forces but only physico-chemical forces.They did not, however, accept the naive mechanistic interpretations of the seventeenth century, nor the idea that animals were "nothing more than machines."Organismic biologists emphasize that organisms have many properties that non-living organisms do not.The explanatory power of the physical sciences is insufficient to explain complex living systems, especially with regard to the interaction between information gained from history and the responses of these genetic programs to the physical world.The phenomena of life have a wider scope than the relatively simple phenomena studied by physics and chemistry.This is why it is absolutely impossible to subsume biology within physics, any more than it is possible to subsume physics within geometry.

There have been repeated attempts to define "life" in the past.Such efforts are utterly ineffective, as it is now clear that no particular substance, object, or force can be equated with life.But the process of life is definable.There is no doubt that living organisms have certain properties that inanimate objects do not possess or behave in different ways.Different scholars emphasize different properties, but I could not find a suitable list of these properties in the literature.The following list of the properties of living organisms which I list is likely to be incomplete and redundant, but, for want of a more complete formulation, it can nevertheless be used to illustrate the differences in classes of properties between living and non-living things.

Complexity itself is not one of the fundamental differences between organic (living) and inorganic (non-living) systems - there are both extremely complex inanimate systems (such as meteorological systems' air masses or galaxies) and a handful of fairly simple organic systems ( such as biopolymers).Systems can vary in complexity, but in general living systems are far more complex than inanimate systems. Simon (1962) defined a complex system as: "The whole is greater than the sum of its parts, not in the final, metaphysically abstract sense but in the important, practical sense. Knowing the properties of the parts and their interactions laws of action, it is by no means trivial to deduce the nature of the whole." I agree with this definition and think that we can still treat some fairly simple systems, such as the solar system, as complex systems (even if we can successfully explain their Complexity).Every level of a biological system has its own complexity, from the nucleus (including its DNA program), to the cell, to any organ system such as the kidney, liver, or brain tissue), to the individual, ecosystem, or society.Biological systems invariably possess sophisticated feedback mechanisms of a precision and complexity not seen in any non-biological system.These feedback mechanisms have the ability to respond to external stimuli, regulate metabolism (energy accumulation and release), and have the ability to control growth and differentiation.

The complexity of biological systems is not chaotic but highly organized.Most structures of an organism are worthless and useless without the cooperation of other parts of the organism: wings, legs, head, kidneys, etc. can only be part of a whole, otherwise they cannot survive.Therefore, all parts are adaptive and capable of procedural purposeful activities.This mutual adaptation of parts is not found in the inanimate world.Aristotle had already perceived the co-adapted function of parts, when he said that "because every device and every body part serves a local purpose, that is to say, a special division of labour, , so that the whole body is destined to attend to all activities" (De Partibus, 1.5 645a 10-15).

Biological organisms are composed of macromolecules with extremely specific properties.For example, nucleic acids in these macromolecular substances can be translated into polypeptides; enzymes are catalysts in metabolic processes; phosphoric acid compounds transmit energy; lipids are components of membranes.Many of these polymers are so specialized and uniquely capable of performing only one specific function (such as rhodopsin in the photoreceptor process) that they occur in the animal and plant kingdoms whenever this specific function is required.These organic macromolecules are in principle no different from other molecules, yet they are much more complex than the small molecular weight molecules that are the normal constituents of substances in the inorganic world.Organic polymers with larger molecular weights generally do not exist in inanimate substances.

The physical world is the world of quantity (Newtonian motion and forces) and mass action.In contrast, the world of life can be regarded as the world of (nature).Individual differences, communication systems, stored information, properties of macromolecules, ecosystem interactions, and many other aspects of biological organisms are properties that predominate.People can convert these properties into quantities, but this will lose the real meaning of biological phenomena, just like describing the paintings of the famous painter Rembrandt with the wavelengths of the main colors reflected on the screen. Same.Similarly, in the history of biology, there have been many brave attempts to convert qualitative biological phenomena into mathematical language, but they all ended in failure because they were divorced from reality.Although Galen, Paracelsus, and van Helmont tried to emphasize the importance of properties in the early days, they also failed due to choosing wrong parameters, but this is the first step in the right direction.Adherents of the quantitative view consider the recognition of (nature) properties to be unscientific, or at best purely descriptive and categorical.Their prejudice just reflects their ignorance of the nature of biological phenomena. (Number) Quantification is important in many fields of biology, but this importance cannot be raised to exclude all aspects related to properties.

All of the above are particularly important in phenomena representing relationships, which are the dominant phenomena in the biological world.Species, taxonomy, ecosystems, association behavior, control, and almost every other biological process involves relationships with each other.These phenomena can only be expressed qualitatively and not quantitatively in most cases. Phylums composed of identical objects are rarely discussed in biology, and populations of unique individuals are almost always studied.This is true for every level of the hierarchy, from cells to ecosystems.Many biological phenomena, especially population phenomena, are characterized by high variability.The progress of evolution, or the rate of speciation, can vary by three to five orders of magnitude from each other, a degree of variation that is extremely rare among physical phenomena.

Whereas entities in the physical sciences (such as atoms or elementary particles) have fixed properties, entities in biology are characterized by variability.Cells, for example, are constantly changing their properties, and so are individuals.Every individual has to undergo drastic changes from birth to death, that is to say, from the original zygote (fertilized egg), through juvenile, adulthood, aging until death.Except for radioactive decay, the behavior of highly complex systems (such as the Gulf Stream and the climate system), and some obscure analogs in astrophysics, there is no such variation in the non-living world.

All living organisms have a historically developed genetic program encoded in the DNA of the zygote (or RNA in some viruses).No similar program exists in the non-living world (except for artificial computers).The advent of genetic programming endows organisms with a special duality, phenotype and genotype (see Chapter 16).Two aspects of this program must be particularly emphasized: first, it is a product of history, which goes back to the origin of life, and thus draws on the "experience" of all ancestors (Delbrhck, 1949); second, it gives the biological organism the purpose of the program The capacity for sexual processes and activities is completely lacking in the non-living world.The presence or absence of a genetic program provides the basis for an absolute distinction between living organisms and non-living organisms, except in the twilight zone of the origin of life. A feature of the genetic program is that it directs precise replication of itself as well as other living systems such as organelles, cells, and whole organisms.There is nothing like it in the non-living world.Occasional errors may occur in replication (for example, one error in ten thousand or one hundred thousand replications).Once such a mutation occurs, it is fixed in the genetic program as a new characteristic of the organism.Mutation is the main source of all genetic variation. The basics of the genetic program were not fully understood until the structure of DNA was elucidated in molecular biology in the 1950s.Yet the ancients had felt that something must be directing the assembly of raw materials into formed organisms.Delbrück (1971) rightly pointed out that the eidos mentioned by Aristotle (although considered immaterial because they are invisible) are conceptually identical to the ontogenetic program of modern developmental physiologists.Buffon's "moule interieure" is a similar command device.However, it was only after the rise of computer science that such procedural concepts were taken seriously.Of particular importance is that the genetic program itself does not change when instructions are passed out.The whole notion of programming is so novel that many philosophers have rejected it. Now that there is a hereditary program by inheritance, the phylum of living beings is divided chiefly not by similarity but by common ancestry, that is to say by a set of commonalities formed by a common history.Many of the criteria of classification employed by logicians are therefore entirely inapplicable to species or higher taxa, and even more so to ontogenetic cell lineages.In other words, the "class" of biologists is not the same as the "category" of logicians.This must be borne in mind in many definitional debates, especially when discussing the classification of species. Natural selection is the differential reproduction of biological individuals with special differences in adaptation advantages, and there is no similar phenomenon in the process of change in the non-biological world.Considering that natural selection has been so often misunderstood until now, it is worth quoting Sewall Wright's brilliant insight: "Natural selection, in which Darwin's two processes of randomness and selection are constantly interacting, is not a mixture of mere chance and mere determinism. in between. A third, and, as far as its consequences are concerned, qualitatively different from the two". The process of natural selection (at least in sexually reproducing species) in turn is characterized by recombination, forming a new gene pool in each generation, thus providing new, unpredictable sources of selection for the next generation. beginning. There has been a long debate among biologists and philosophers about whether there is a difference between the determinism and predictability of physical and biological processes.It is a pity that it has consistently confused epistemological and ontological aspects, thus obscuring the essence of the problem. The word "prediction" is used in physics and biology to mean completely different things.When philosophers of science talk about predictions, they mean logical predictions about whether individual observations agree with a theory or scientific law.For example, Darwin's theory of common ancestry allowed Haeckel to predict that "missing links" between humans and apes would be found in the fossil record.The validity of a doctrine is tested by the predictions it allows.Since physical science is much more a system of doctrine than biology, prediction plays a more important role in physical science than in biology. Prediction in everyday language refers to inferring the future from the present, and it involves the sequence of events, which is "temporal prediction".Absolute temporal predictions are often possible within strictly deterministic physical laws, such as predictions of solar and lunar eclipses.Ad hoc predictions are rarely possible in the biological sciences.The sex of the next child in a family cannot be predicted.No one could have predicted at the beginning of the Cretaceous period that the thriving population of dinosaurs would become completely extinct by the end of this geological era.In general, predictions in biology are more probabilistic than those in the physical sciences. There are two categories of predictions, and this must be kept in mind when discussing causality and its interpretation. G． Bergmann once defined the explanation of causality as "when the present state of a system is known, the future state of the system is permitted to be predicted due to some law of nature." In essence this is repeating the well-known Laplace's boast .This argument has been refuted by Scriven (1959: 477), who argues that (temporary) predictions "are not part of causation, and that "whenever explanations of causality do not predict the state of affairs at issue, they cannot be considered It just doesn't work. " In biology, especially in evolutionary biology, explanations are generally associated with historical narratives.As early as 1909, Baldwin put forward two reasons why biological events are often unpredictable: firstly, due to the high complexity of biological systems, and secondly, unanticipated phenomena often emerge at higher levels of the hierarchy. novelties.I can think of other factors myself.Some of all these factors can be seen as ontological uncertainties, others are epistemological.These factors do not weaken the principle of causation', understood in the 'a posteriori' sense. Here are a few factors that come to mind. The randomness of a state of affairs related to the meaning of a state of affairs.Spontaneous mutations due to DNA replication errors amply account for this cause of uncertainty.As far as this example is concerned, there is no connection between the molecular state of affairs and the underlying meaning.So are such events as crossing over, chromosome segregation, gamete selection, mate selection, survival, etc.The molecular phenomena and mechanical movements associated with these processes are independent of their biological effects. unique.The nature of unique states of affairs or of newly created unique entities cannot be predicted (see above). The degree of randomness interference.Give an example to illustrate the influence or effect of this factor.Suppose a species consists of a million different unique individuals.Every individual has the opportunity to be wiped out by enemies, killed by pathogens, weather disasters, malnutrition, unable to find a mate, and offspring die before they are fertile, etc.These are a few of the countless factors that determine successful reproduction.Which of these factors will come into play depends on highly variable, unique and unpredictable environmental conditions, so we have two highly variable systems (unique individuals and unique environmental conditions) interacting with each other.Chance largely determines how they mesh together. Complexity.There are so many feedback mechanisms, homeostatic mechanisms, and potentially diverse metabolic pathways in each biological organism that it is impossible to fully describe them, and thus predict their operation.Moreover, the analysis of such a complex system would necessarily destroy it, making the task of analysis impossible. New and unforeseen properties emerge at various levels of the hierarchy (discussed in more detail later). The above eight properties, together with another that will be mentioned below in the discussion of reductionism, clearly show that living organisms are quite different from non-living ones.Yet none of these properties contradicts a strictly mechanistic interpretation of the world. Because biological organisms have the above eight characteristics, some people argue that biological science should be an independent science.This assertion is quite foreign to many physical scientists and philosophers of the physical sciences, who maintain that there is no apparent independence of the biological world and that all doctrines of biology can be reduced or reduced, at least in principle, to The doctrine of physics.They claim that only in this way can the integrity and unity of science be maintained. This argument that reductionism is the only reasonable approach to the relationship between the sciences is also often supported by the claim that if it is not reductionism it must be vitalism.But in fact, it's not.While some anti-reductionists in the past were indeed vitalists, almost all modern anti-reductionists firmly deny vitalism. In fact, the meaning of the word "reduce" is very ambiguous.When reading the writings of reductionists, it is used in at least three different senses (Dobzhansky and Ayala, 1974; Hull, 1973b; Schaffner, 1969; Nagel, 1961). constitutive reductionism Constitutive reductionism holds that the material composition of biological organisms and inorganic substances is exactly the same.In addition, it also believes that there is no contradiction between the state of affairs and processes in the biological world and the physical-chemical phenomena at the atomic and molecular levels.These views are accepted by modern biologists.The difference between inorganic substances and living organisms is not in the constituent substances but in the organizational structure of the living organisms (biological systems).So constitutive reductionism is indisputable.Almost all biologists have adopted these arguments for constitutive reductionism, and have done so for the past two hundred years or so (except vitalists).Acknowledging compositional reductionism and denying other forms of reductionism is not a vitalist, although some philosophers see it otherwise. This reductionism asserts that in order to understand a whole it must be broken down into its constituent parts, and that these parts must be further broken down into their constituent parts, down to the lowest level of the hierarchy.In biological phenomena, this means reducing the research of all phenomena to the molecular level, that is to say, "molecular biology is everything in biology." This kind of explanatory reductionism can really explain the problem sometimes.For example, the function of genes was not clear until Watson and Crick solved the problem of the structure of DNA.Likewise, organ function is generally not fully understood until molecular processes at the cellular level have been elucidated. However, interpretive reductionism also has many strict limitations.One of these is that the processes at the higher levels of the hierarchy tend to be mostly independent of the processes at the lower levels.Lower-level units may be well integrated to function as higher-level units.For example, the function of bone joints can be explained without knowing the chemical composition of cartilage.In addition, in modern surgery, plastic can be used to replace the surface of the bone joint to completely restore the normal function of the bone joint.Breaking down a functional system into its component parts may be beneficial in many cases to explain the problem, while in many other cases it may be disadvantageous or at least inappropriate.The facile use of explanatory reductionism has often done more harm than good in the history of biology.For example, the early cell theory interpreted biological organisms as "aggregates of cells." Early population genetics regarded genotypes (genotypes) as independent gene aggregates with constant-fitness values. Extreme decomposition (analytical) reductionism fails because it ignores the interactions between the constituent parts of a complex system.An isolated constituent, which almost without exception has properties different from those of the constituent as part of the whole, when separated no longer exhibits the interaction between the constituents. Rene Dubos (1965: 337) speaks well of why the atomized approach is utterly unsuitable for complex systems: "In the most common and perhaps most important phenomena of life, the constituent parts are so interdependent that once If they are separated from the functional whole, they will lose their own characteristics and meanings, and in fact deny their own existence. In order to study the problems of complex organizational systems, it is necessary to study the problems of the coordination and integration of multiple interrelated systems. " The most important conclusion from a critical examination of interpretive reductionism is that lower levels of a hierarchy or system can provide only limited data or information about properties or processes at higher levels.Just like the physicist P. W． Anderson (1972: 393-396) once said: "The more elementary particle physicists tell us about fundamental laws, the less they seem relevant to other practical problems in science, let alone to Social problems.” In addition, it is even more wrong to use the word “reduction” as a method of analysis. Analytical research on complex biological systems can also be done in many other ways.For example, animal genetics initially used horses, cows, dogs, and other large mammals as experimental materials.Later geneticists turned to birds and various rodents.In order to obtain animals with more generations in a year or a simpler genetic system, the yellow fruit fly or other fruit flies were used instead of rodents in many genetic laboratories after 1910.This was followed by Neurospora or other fungi (yeasts) in the 1930s.Finally, in molecular genetics bacteria (such as E. coli) and various viruses are used.In addition to the short generation time (more generations within a certain period of time), the selection of genetic experiment materials also strives to discover the simplest possible genetic system, in order to deduce more complex systems from it.Generally speaking, this wish has been realized, but it was finally found that the genetic systems of prokaryotes (bacteria) and viruses are not completely comparable to those of eukaryotes. The genetic material of eukaryotes is organized into complex chromosomes, while the former two no.Simplification must therefore be done with great care.There is often a danger that moving it to a system, simple as it is, becomes so different that it can no longer be compared. This reductionist claim that theories and laws developed in one scientific field (usually more complex fields or at higher levels of the hierarchy) can be regarded as special cases of theories and laws developed in another scientific field or instance.If this claim prevails, then, in the strange language of some philosophers of science, one branch of science is "reduced" to another.To take a special example, biology is reduced to physics when the terms of biology are defined in terms of physics, and the laws of biology are deduced from the laws of physics. Such doctrinal reductionism has been tried repeatedly in the physical sciences, but according to Popper (1974), the attempt has never been fully successful.I have never found biological theory reduced to physico-chemical theory.After the discovery of the structures of DNA and RNA, and certain enzymes, the claim that genetics has been reduced to chemistry is untenable.In the traditional theory of genetics, there are indeed many unclear black boxes whose chemical nature has been gradually clarified, but this has not affected the nature of the theory of genetics at all.That is to say, it is indeed gratifying to make up for the shortcomings of traditional genetic theory through chemical analysis, but it cannot be said that genetics has been reduced to chemistry at all.Some basic concepts of genetics, such as gene, genotype (genetic type), mutation, diploidy, heterozygosity, segregation, recombination, etc., are not chemical concepts at all, and cannot be found in chemistry textbooks at all. Doctrinal reductionism is wrong because it confuses process and concept. Beckner (1974) once pointed out that although some biological processes such as meiosis, gastrulation, and predation are also chemical and physical processes, they are biological concepts after all and must not be reduced to physical-chemical concepts. Furthermore, any adapted structure is the result of selection, again a concept that cannot be expressed in strict physico-chemical terms. Doctrinal reductionism is also wrong because it fails to take into account that the same state of affairs has completely different meanings in different conceptual structures.For example, the phenomenon of courtship can be described completely according to the language and conceptual structure of physical science (such as action, energy conversion, metabolic process, etc.), and can also be expressed by the conceptual structure of ethology or reproductive biology.The same is true of the many states of affairs, properties, relations, processes, etc., that pertain to living organisms.Such organic phenomena as species, competition, territory, migration, hibernation, etc. are at best incompletely described in terms of physical concepts, not to mention that they are often irrelevant to biology. The above discussion of reductionism can be summarized as follows: the analysis of any system is an important research method, but the attempt to "reduce" purely biological phenomena or concepts to the laws of physical science can promote understanding. Developed but also extremely rare.Reductionism is at best an empty and meaningless point of view, not to mention it is often very misunderstood.The emergence phenomenon discussed below can fully illustrate this problem. systems are almost always characterized by the fact that the properties of the whole (total) cannot (theoretically) be deduced from the parts that make up the whole, even if the properties of each part or its partially incomplete combinations have been fully studied .The emergence of new features in a whole is called emergence. 'Emergence is often used to explain complex phenomena such as life, will, and consciousness.In fact, emergence can also be applied to inorganic systems.As early as 1868 T. H．He Jinli has mentioned that the properties of water - "watery" - cannot be deduced from what we know about the properties of hydrogen and oxygen. Lloyd Morgan (1894) emphasized the importance of emergence.He believes that there is no doubt that "at different levels of organizational structure, the compositional configuration of matter shows new and unexpected phenomena, including the most striking adaptation mechanism." Emergence is very common, Popper (1974:: 281 ) once said: "We live in a universe of emergent novelties." Emergence is a descriptive concept that seems incompatible with analysis (decomposition), especially in more complex systems .Simply saying (and it has been done in the past) that emergence is caused by complexity is certainly not an exact explanation.Perhaps the two most notable features of wholes are (1) that they can in turn act as higher-level components of a system; and (2) that they can affect the properties of lower-level components.The latter phenomenon is sometimes called "downward causation" (CamPbell, 1974: 182).Emergentism is a thorough materialist philosophy. Whoever denies it will inevitably adopt a panpsychism (Pan-psychism) or animistism (hylozoism) view of material theory. There are two false claims against emergence that must be refuted.The first is that emergentists are vitalists.This view was indeed appropriate for some emergentists of the nineteenth and early twentieth centuries, but it is inappropriate for modern emergentists, who accept constitutive reductionism without reservation and are therefore not vitalists.The second claim is that some emergentists propose that the organism can only be studied as a whole, and any further decomposition (analysis) is not feasible.Perhaps some holists have said this, but this view is the opposite of ninety-nine percent of emergentists.All emergentists agree that explanatory reductionism is imperfect because higher levels of complexity in the hierarchy reveal new, ex ante unpredictable features.Because each level has properties that lower levels do not have, the study of complex systems must be done at each level. Some scholars have recently discarded the word "emergence" because of its more or less metaphysical overtones.Simpson (1964b) considers it a "structural" method, Lorenz (1973) attributes it to flickering, not stable.However, many scholars currently use the term "emergence", which, like "choice", has been "purified" in the process of removing vitalistic and teleological connotations, so I see no reason why it should not be used. Complex systems often have a hierarchical structure (Simon, 1962). Entities at a certain level are combined to form new entities at a higher level. For example, cells form tissues, tissues form organs, and organs form systems.There are also hierarchical structures in the non-biological world, such as elementary particles, atoms, molecules, crystals, etc. However, the hierarchical structure is only of special significance in living systems. Pattee (1973) argued that all problems in biology, especially those related to emergence (see below), are ultimately problems of hierarchical structure. Although hierarchies are of general interest, the types and properties of each are not well understood.There are clearly two types of hierarchical structures in biology.One type is constitutive hierarchies, such as various polymers, organelles, cells, tissues, organs, etc.In such a hierarchy lower-level components, such as tissues, are combined into new units (organs) that have a single function and emergent properties.The formation of constitutive hierarchical structures is one of the most important characteristics of biological organisms.At each level there are its own problems, puzzles to be solved, and various theories.Each of these levels constitutes a separate discipline of biology: Molecule - Molecular Biology, Cell - Cytology, Tissue - Histology, etc., up to Biogeography and Ecology.Identifying these hierarchies has traditionally been a way of dividing biology into disciplines.Scholars devote themselves to different levels of research according to their interests.It is natural that molecular biologists are not at all interested in the research topics of functional morphologists or zoogeographers, and vice versa.Questions and discoveries at other levels are usually irrelevant to a scholar engaged in a particular level of research.To fully understand the phenomenon of life, it is necessary to study all levels. However, as pointed out above, the research findings at the lower levels generally do not help to solve the problems raised by the higher levels.A famous Nobel Prize-winning biochemist once said: "There is only one biology, and that is molecular biology." This can only show his ignorance of biology. Since so many components are involved in the proper functioning of biological systems, it is a strategic choice for a research scientist to choose which level of research will make the greatest contribution to the understanding of living systems under current conditions. question of interest.This also includes discarding some of the unopened black boxes. Another completely different hierarchical structure can tentatively be named agglomerative hierarchical structure (aggtegstioll "lhiCfstChy). The most well-known example is the hierarchical structure of Linnaeus taxonomic categories. From species to genus, family, to phylum and kingdom. This完全是为了方便所作的安排。在这样的等级结构中，较低层次的单位——例如属下的种，或科下的属——并没有经由任何相互作用组合成突现的新的较高层次作为一个整体。它只是由分类学家将分类群按高低等级排列而成。这种说法的正确性并不会由于（自然的）较高分类群中的所有成员都是一个共同祖先的后代这一事实而削弱。将分类范畴校等级排定的这种等级结构基本上只是一种分类手段或策略。 除此而外，我不知道是否还有其它种类的等级结构。 从亚里斯多德开始，许多远见卓识的生物学家对完全按还原论观点看待生物学问题一直不满意。其中大多数生物学家只是强调整体，也就是系统的集成（整合）。另一些学者则求助于形而上学的力量来规避科学解释。直到20世纪“活力论”一直受宠。当Smats（1926）提倡采用“整体论”这个术语来表示整体大于部分之和时，这个术语本来是很合式的，然而却不幸地从一开始就被他赋予了活力论观点。“机体论”这个术语似乎是由Ritter（1919）首先创用，现在已广泛流行（Beckner，1974：163）。Bertalanffy（1952）曾列举了三十多位赞同整体论一机体论观点的著名学者来说明这种情况。这个名单并不完整，其中甚至还不包括Lloyd Morgan，Jan Smuts，JSHaldane。由Francois Jacob（1970）提出的“集成体”（“整合体”，integron）概念虽然引起了很多争论，然而却是对机体论思想的支持。 和多少具有“活力论”观点的早期“整体论”不同，近代的“整体论”是彻底唯物主义的。它强调较高等级层次的单位大于其部分之和，因此将整体分解为它的组成部分总会遗留下未分解的残存物，换句话说，那就是说解释性还原论不能说明问题。更重要的是“整体论”还强调了每个层次的问题和学说的独立自主性，最终就必然是生物学作为一个整体的独立自主性。科学的哲学再也不能忽视生物学的机体论概念，而仍将之看作是活力论因而属于形而上学。科学的哲学若仍然囿于在非生物世界所观察到的事物就是十分可悲的。 许多科学家集中精力于孤立事物和孤立过程的研究，好像它们是存在于真空之中。“整体论”的最重要方面可能是它着重于关系（relationships）。我总感到自己对关系没有予以足够的重视。这就是为什么我把物种概念称为关系（性）概念，为什么我研究遗传革命（1954）和遗传型的内聚性（1975）——这两者所研究的都是关系（性）现象。我对豆袋遗传学的非难（1959d）也是基于同一原因。 其它的人也有同样感受。画家Georses Braque（1882- 1963）曾声称：“我不相信细节，我只相信它们的关系。”当然，爱因斯坦的全部“相对论”就是奠基于对关系的考虑之上。当讨论在不同的遗传环境中，基因的选择值（selective value）也随之变化时，我曾开玩笑地将这一概念称之为基因相对论。 在将生物学和物理科学加以比较时，我一直把生物学当作是一门同质的科学（homogenous science）来看待。这种看法是不对的。实际上生物学按几种重要方式被分成几类和异质化了。几千年来生物学现象一直被分为两类：医学（生理学）和博物学。这实际上是一种颇有远见的划分，远比随后为方便起见分作动物学、植物学、真菌学、细胞学、遗传学等等更有见识。因为生物学可分为研究近期原因（Proximate causes），即生理科学（广义的）的主题；和研究终极（进化）原因，即博物学的内容（Mars1961）。 什么是近期和终极原因？这最好是用具体例子来说明。为什么北美温带的某种鸣禽在八月二十五日的夜间开始南飞？这一现象的近期原因是这种鸣禽属于对光周期敏感的候鸟，它之所以在特定的时间起飞则是由于白昼的长短已降低到某一阈值，它在生理上已作好迁移的准备；并且由于气候条件（风，温度，气压）有利于当夜南飞。然而栖息在同一林带，昼长同样缩短，气候条件相同地区的枭（猫头鹰）及鳾（五十雀）却并不南迁；实际上这两种鸟由于缺乏迁徒的冲动或愿望成年地留在那个地区。那末，很明显候鸟与留鸟之间的差异必然有另外完全不同的原因。这就是经历了亿万年进化过程的自然选择所获得的遗传型。这遗传型决定了哪些种群或种是候鸟，哪些不是候鸟。某些捕食昆虫的鸣禽经过自然选择成为候鸟，否则在冬天就会饿死。其它种类的鸟由于在整个冬天都能找到食物，经过自然选择避免了危险的迁徙，对这些鸟类本身来说，迁徙也是不必要的。 举另外一个例子，性二形性（sexual dimorphism）的近期原因可能是激素的或某些遗传性生长因素的作用，而其终极原因则可能是性选择或食物生境差别利用的选择优势（selective advantage）。总之，任何生物学现象都目源于这两类不同的原因。 近期-终极这术语的起源还不很清楚。斯宾塞和GeorgeRomanes曾经很含糊地用过它们，然而首先明确地区别近期与终极原因涵义的则显然是John Baker。终极原因是说明某一特定遗传程序进化（选择）的原因，而近期原因则负责（姑且这样说）对应于当时环境刺激的贮存遗传信息的发放。“因此在繁殖季节（一定月份中）幼小动物的食物（昆虫）丰富程度就是终极原因，而白昼的长短则是其近期原因”（Baker，1938：162）。 涉及两种原因的两类生物学是完全独立的。近期原因和有机体及其组成部分的功能和发育有关，包括从功能形态学到生物化学。进化的，历史的或终极原因则企图说明为什么某一生物有机体是现在这种样子。和无机物对比，有机体因为具有遗传程序所以有两种不同的原因。近期原因和某一生物个体遗传程序的解码有关，进化（终极）原因和遗传程序经历时间发生变化以及这些变化的缘由有关。 功能生物学家非常注意结构元件的运行和相互作用，从分子到器官一直到整个个体。他一再重复的问题是“怎样”（“如何”？How）？它是怎样运转的？是怎样发挥作用的？研究骨关节的功能解剖学家和研究遗传信息传递中DNA分子功能的分子生物学家都同样运用这种方法。功能生物学家力求将他所研究的特定组成部分孤立起来，在研究中他通常是研究一个单独的个体、单个器官、单个细胞、或细胞中的单个部分。他试图消除和控制一切变数，在恒定或变化条件下重复试验直到他认为己弄清了所研究的组成元件的功能为止。功能生物学家的主要技术方法就是实验，和物理学家、化学家的步骤基本相同。将所研究的现象从有机体的复杂体系中分离出来确实能达到纯粹物理或纯粹化学实验的目标。虽然这种方法有一定的局限性，但必须同意功能生物学家的这样一种看法，即这种简化处理是达到他们的特殊目标所绝对必需的。生物化学和生物物理研究的引人注目的成果充分论证了这种直接的、虽则明显简单化的处理的合理性（Mayr．1961）。对干自哈维到伯尔纳以至到分子生物学的功能生物学的成就与方法学方面也是无可争议的。 每种有机体，无论是一个个体还是一个物种都是悠久历史的产物，这历史可以回溯到3of乙年前。正像德尔布吕克（1949）所说的那样：“当一位成熟的物理学家初次和生物学问题打交道时，他会对生物学中没有任何“绝对现象”的情况而伤透脑筋，迷惑不解。生物学中每件事物都由时间和空间制约着。他所研究的动物、植物或微生物仅仅不过是形式变化了的进化链条中的一个环节，它们之中的任何一个从来也没有永恒的合理性。” 除非衬托着这种历史背景来研究，否则对有机体的任何结构或功能都将无法充分认识。探索有机体的现存性状，特别是适应的原因是进化生物学家的主要任务。进化生物学家对千姿百态的多样性以及达到这种多样性的途径印象极深。他研究是什么力量使得动物和植物发生变化（其中有一部分由古生物学记载了下来）。他还研究导致奥妙无穷的适应的各个步骤，而这正是生物界各个方面的特征。 进化生物学中几乎所有的现象和过程都是通过基于比较方法的推论来解释。而这些又只有经由非常详尽仔细的描述性研究才有可能成功。对于进化生物学方法论的如此重要的组成部分描述性研究往往被忽视。达尔文、魏斯曼、壬席、辛普森、Jordan、Whitman等人的概念性突破如果没有描述性研究作坚实基础并在此基础上建立他们的概念结构，这种突破是完全不可能的。博物学在其早期必然是纯粹描述性的，早期的解剖学也如此。十八世纪和十九世纪早期系统学家对自然界多样性进行分类的努力就已经超越了单纯的描述。1859年达尔文的出版以后进化生物学独立成为合法的生物学分支就再也没有疑问了。 功能生物学常被看作是定量科学；与此对照，进化生物学在很多情况下可以合理地称之为定性的学科。“定性”这个词是在科学革命时代的反亚里斯多德时期中作为贬义词使用的。尽管经过莱布尼茨以及其它许多具有远见的学者的努力，这贬义仍然一直延续到达尔文学说革命时期。在达尔文学说革命的冲击下社会的知识文化气氛发生了转变，从而促进了进化生物学的发展。 这一革命并不是立刻就取得了胜利。很多物理学家和功能生物学家一直不理解进化生物学的特殊性质和意义。Driesch在他三十年代写的自传中曾经不无自得地提到生物学教授的职位“目前只颁发给实验学者。系统学的问题已经完全退居幕后。”他根本忽视了进化生物学的存在。这种态度在当时的实验生物学家中相当普遍。 海克尔可能是第一位生物学家站出来坚决反对一切科学都必须像物理科学那样以数学为基础的观念。他坚决认为进化生物学是一门历史性科学。他曾说过，胚胎学，古生物学以及种系发生史等就更不待言的是历史性科学，我们现在也许可以用“由历史形成的遗传程序所控制以及遗传程序在时间上的历史变化”这样的词句来代替“历史性的”。遗憾的是，这种观点并没有被更多的人接受。Baldwin在1909年曾指出由于接受了达尔文主义的观点，生物学家的思想发生了多么大的变化。最后他写道。“物理科学和力学定律对科学和哲学思想的统治在二十世纪开始的今天已经宣告结束。”他的这种乐观主义并没有实现，因为现在仍然有许多哲学家在著书立说时就好像达尔文从来就不存在，进化生物学并不是科学似的。 科学的哲学在其发展初期深深植根于物理学、特别是力学的基础之上。在这些学科中任何过程和事件都可看作是特定定律的结果，预测和原因是对称的。与此对映，与历史有关的科学现象就和这种概念不符。物理学家Hermann Bondi（1977：6）曾正确指出：“关于太阳系起源、地球上生命起源以及宇宙起源的各种学说就具有特别的性质（与物理学的传统学说相比较而言），这种特别的性质在于试图阐述的是在某种意义上独特的事件。”独特性的确是进化历史中任何事件的突出特征。 因此，有一些科学哲学家主张在进化生物学中不是由学说来提供说明而是由“历史性叙述”作出解释。 T． A． Goudge（1961：65-79）曾经讲过：“当讨论到生命历史中特别重要的独一无二的事件时，进化论就需要叙述性解释…。叙述性解释的构成并不涉及任何定律。…每当进化过程中的某一事件需要作叙述性解释时，这一事件就不是某一类（群）中的一个例子，而是独一无二的，它只发生一次，并不（按同一方式）重复出现。…。历史性解释是进化论的基本部分。” Morton White（1963）进一步发展了这一思想。主题这个概念在历史性叙述的逻辑结构上至为重要。任何种系、动物区系（在动物地理学中），或任何较高分类单位从历史性叙述学说的观点看来都是主题，而且在时间上有连续性。历史性叙述在宇宙起源学、地质学、古生物学以及生物地理学中都具有重要作用。 历史性叙述之所以具有解释意义是因为在历史顺序中较早的事态往往是其后事态的原因。例如恐龙在白垩纪末期灭绝就空出了大量的生态位（小生境），这样就为哺乳动物在古新世和始新世的惊人辐射创造了条件。因此，历史性叙述的目的之一就是为后续事态寻找原因。 按本质论逻辑训练出的哲学家似乎很难理解独特性和事态的历史顺序的特殊性质。他们否定历史性叙述的重要性的企图或接定律将之公式化的企图都是无法令人信服的。 进化生物学最鲜明的一个方面是它所提出的问题。近期原因的生物学所提出的是“什么”和“怎样”的问题，而进化生物学提出的是“为什么”的问题，为什么有些有机体彼此非常相似而另一些却又完全不同？为什么大多数有机体具有两性？为什么动物和植物多种多样？为什么有些地区的动物区系有很多种而其它的则很少？ 如果某一有机体具有某些特征，这些特征必然是由其祖先传下来的，或者是由于选择优势而获得的。“为什么”（ Why）的问题如果指的意思是“为何”（what for）则在非生物界就毫无意义。人们可以问“为什么太阳很热？”这只是指“太阳的热是怎样来的（how come？）？”与此相反，在生物界中，“为何”的问题就具有很大的启发性。“为什么血管中有瓣膜”这个问题促使哈维发现了血液循环。茹（Roux，1883）提出了“为何在有丝分裂时细胞核要经历重新组织的复杂过程而不迳直一分为二？“这个问题使得他对细胞分裂首先作出了正确解释。他充分认识“关于生物学过程的意义可以按两种方式提出问题。头一种方式涉及到这过程在什么生物结构中发生以及这过程的生物学功能。另一方式是询问这一过程的开端和进程的原因。”因此进化生物学家在试图分析进化的原因时必须随时提出为什么的问题。 一切生物学过程既有近期原因又有终极原因。生物学历史中的很多混淆不清的情况就是由于生物学家们或者只注意近期原因，要不就只问终极原因的结果。例如关于“两性异形的原因是什么”这个问题。 T． H．摩根（1932）就嘲笑过进化论者对这一问题的种种推测虽他认为答案非常简单：当个体发生时雄性和雌性组织受到不同激素的影响。他根本没有考虑到雄性和雌性的激素系统为什么不同这个进化问题。他对两性异形在求偶以及其它行为学和生态学上的涵义一概不予理会。 另外再举一个例子：受精作用的意义是什么？”有些功能生物学家在考虑这个问题时认为未受精卵是静止的，精子一旦进入卵后发育即行开始（由卵裂显示）。因此某些功能生物学家主张受精作用的意义在于引发发育。进化生物学家则指出，在单性生殖的物种中并不需要受精作用引发发育，因而他们的结论是，受精作用的真正意义在干实现父本和母本基因的重组，这样的重组产生了自然选择所需要的遗传变异性（Weismann，1886）。 从上述的例子可以明显地看出，生物学问题只有在其近期原因和终极原因都得到阐明后才能完满解决。此外，进化原因的研究和通常物理-化学性近期原因的研究同样都是生物学的一部分。研究遗传程序的起源及其随进化历史而变化的生物学与研究遗传程序转译（解码）的生物学（即对近期原因的研究）都是同等重要的。Julius von Sachs，Jacques Loeb以及其它一些机械论者认为生物学是完全研究近期原因的观点明显是错误的。 现在已经很清楚，生物学需要有一种新的哲学。它应当包括并且综合功能生物学的控制论——功能一组织结构的观点，以及进化生物学的种群-历史程序-独特性-适应的概念。虽然这种新哲学的基本轮廓是清晰的，但在目前它还只是有待完成的宣言似的东西，并非成熟的概念体系。它在批判逻辑实证论、本质论、物理主义和还原论上是毫不含糊的，然而在其主题方面却又犹豫趑趄不前。近年来就此写过文章的一些学者如壬席，辛普森，Mainx，与Ayala－Dobzhansky合作的学者，以及生物学哲学家（如Beckner，Campzell，Hull，Munson等）则不仅仅在着重点上，而且在某些基本原则上（例如对突现论的态度）彼此的看法都很不一致。但是这种情况现在已有了令人鼓舞的进展。很多对此有远见的学者已放弃了过去的极端观点；他们之中没有人接受各种不同形式的活力论，也没有人支持解释性还原论。随着生物学的新哲学的边界已明确地标出，在不久的将来取得真正的综合是完全有希望的。 科学哲学家当涉及生物学问题时常把很大一部分精力放在悟性（理智）、意识和生命这样一些问题上。我认为他们是在自找不必要的麻烦。就意识而论，它是无法下定义的。根据某些评议标准，甚至低等无脊椎动物也有意识，而且就连原生动物在其回避反应中可能也有。至于是否要沿下去追索到原核生物（如磁细菌）这就完全是个人的兴趣了。总而言之，意识这个概念甚至近似的也无法下定义，因而详细研究它是不可能的。 就“生命”和“理智”这两个词而论，它们只不过是活动的具体化，并不是实体的独立存在。“理智”指的并不是物而是思维活动；由于思维活动普遍地出现在动物界（这要看怎样给思维下定义），因而可以说有机体只要有思维活动（过程）就有理智。同样，“生命”只是生存（生活）过程的具体化。生存的评议标准可以提出来，也可以被采纳，然而在活的有机体中并没有作为独立的“生命”这样一类的东西存在。将“生命”类似于灵魂那样而赋予单独存在的确是太危险（Blandino，1969）。避免使用那些将过程具体化的名词大大有利于对生物学所独具的现象进行分析。 生物学独自的哲学的逐步形成，是一个漫长痛苦的过程。早期的尝试是注定要失败的，因为当时对生物学的事实了解很少，而且不确切或错误的概念很流行。这可以用康德的生物学哲学作为例子来说明。康德并不了解生物学的题材必须首先由生物学家本人（通过科学！）整理清楚。例如按因果关系解释林奈的等级结构就是系统学家的任务（这任务由达尔文通过他的共同祖先学说完成的），阐明适应的起源而又不求助于超自然力量是进化论者的任务（已由达尔文同华莱士按自然选择学说解决）。一旦有了这些解释，哲学家才有可能开展工作。他们确实这样做了，然而遗憾的是（就全体来说）是和达尔文作斗争并支持生物学上有错误的学说。这种情况一直持续到现在，也就是说现在还有像Marjorie Grene，Hans Jonas等人的著作。 我认为应当公正地说，像壬席， Waddinston，辛普森，Bertalanffy，Medawar，Ayala，迈尔，Ghiselin等这些生物学家对生物学哲学所作的贡献远远超过老一代的哲学家，包括Cassirer， Popper，Russell，Bloch，Bunge，Hempel1，Nagel。只有最年轻一代的哲学家（Beckner，Hull，Munson，Wimsatt，Beatty，Brandon）最终才得以摆脱已废弃的生物学学说的羁衅，如“活力论”，“定向进化论”，“骤变进化”，“二元论”或“实证还原论”学说。“人们只需要读到在其它方面是如此卓越的一位哲学家E．Cassirer对康德《判断力批判》一文的论述就会认识传统的哲学家要了解生物学问题是多么困难。为了解脱他们，应当说生物学家也负有责任，因为他们对生物学的一些概念性问题没有作明确的分析。他们只见树木不见森林。 作为生物学哲学的基础应当包含哪些原则或概念？这很不容易详尽说出，但是根据前面的讨论很明显地可以指出： （1）为了充分了解生物有机体不能单靠物理学和化学的学说； （2）必须充分考虑有机体的历史性本质，特别是它们具有从历史上获得的遗传程序； （3）在大多数等级（结构）层次（从细胞开始）的个体都是独特的并形成种群，个体的变异是其主要特征； （4）有两类生物学，功能生物学提出近期原因的问题，进化生物学提出终极原因的问题； （5）生物学的历史由概念（的建立）来支配，并且为概念的完善化、修正和偶尔的废弃所左右； （6）生物有机体的构型复杂性（ patterned complexity）被等级结构组成，等级结构较高层次具有突现特征； （7）观察和比较是生物学的研究方法，和实验（方法）具有同等的科学性和启发性； （8）坚持生物学的独立性并不意味着支持活力论、定向遗传论或其它与化学或物理学定律相矛盾的学说。 生物学的哲学必须包括一切主要的生物学特有的概念，不仅是分子生物学，生理学和发育（发生）学的概念，还包括进化生物学的概念（如自然选择、总适合度、适应、发育、世系），系统学概念（如种，阶元，分类），行为生物学及生态学概念（如竞争，资源利用，生态系统）。 在这里我甚至还可以加上几条“戒律”（donts）。例如，生物学哲学不要在还原论上浪费精力。它也不应当采用现成的物理学哲学作为自己的出发点（看到这方面的一些有名著作很少涉及科学研究的具体实践，特别是生物学的研究实践，未免令人泄气）。考虑到定律在大多数生物学学说中不起什么作用，因此生物学哲学不应当把注意力专注在定律上。换句话说，我们所需要的是一种不受约束的生物学哲学，它和活力论以及其它非科学思想观念，物理主义的还原论（它不能正确对待生物学现象和系统）都不沾边。 C． P． Snow在他的一篇有名文章中谈到，在科学和人文学之间存在着无法渔通的隔阂。关于他提到的物理学家和人文学者之间的信息沟（communication gap）的确存在，但是在物理学家和博物学家之间也同样存在着这样的鸿沟。不仅如此，甚至在功能生物学与进化生物学的代表人物之间也严重地缺乏信息交流。此外，功能生物学和物理科学相仿，也很重视定律、预测、定量和计量以及生物性过程的功能方面。而在进化生物学中则特别重视性质、历史性、信息、选择值等问题，这些问题也和行为科学及社会科学有关，但与物理学关系甚少。因此有人将进化生物学看作是物理科学与社会科学及人文学之间的桥梁也并不是毫无道理。 Carr（1961：62）将历史和科学加以比较后认为历史与一切科学在五个方面不同：（1）历史专门研究独特的事态，科学则研究一般的事态I（2）历史从不教训人;（3）历史不能预测；（4）历史必然是主观的;（5）历史（和科学不同）包括宗教与道德问题。这些区别只适用于物理科学。以上（1），（3），（4），（5）项对进化生物学也大体适用，而且Carr也承认在这些之中（例如第二项）也不全然适用于历史。换句话说，科学与非科学之间的明显断裂并不存在。 科学对人及其思想的影响一直有争议。哥白尼，达尔文，弗洛伊德深刻地改变了人们的思想是勿容置疑的。过去几百年中物理科学主要是通过技术发挥影响。Kuhn（1971）认为一位科学家要真正地对人们的思想发生影响，他必须首先被一般人（门外汉）了解。不管某些数学物理学家（包括爱因斯坦和玻尔）多么有名气，“就我所知，他们之中没有一个人对科学领域之外的思想发展有过什么影响，充其量也不过是微不足道的间接影响。”Kuhn的看法是否正确且当别论，然而可以肯定某些科学家对理解力强的门外汉的思想影响要比对其它人更多。这很可能取决干科学家的研究主题是否和一般人所直接关心的问题以及关心的程度有关。因此生物学、心理学、人类学以及有关的学科很自然地比物理科学对人们思想的影响要大得多。 在科学兴起之前是由哲学家负责（姑且如此说）促进认识世界的任务。自从19世纪以后，哲学日益退缩到研究逻辑学和科学的方法论上，放弃了原先它所一直专心致志的形而上学、本体论、认识论的广大阵地。不幸的是，这片阵地实际上大部分变成了无人地带，因为当时大多数科学家为探索自己的专门研究而感到心满意足，根本不去考虑他们自己的研究结果会怎样影响到人们的基本要求和一般认识论的问题。另一方面，哲学家又感到科学发展如此迅速，如果不是不可能也是难于跟上，从而转向研究琐碎或玄妙的问题。科学家和哲学家联合作战双方受益的极好机会并没有被抓住而轻易地放过了。 人们有时常说科学和宗教的说教大不相同，科学是非人格化的，超然的，不受感情支配的，从而是完全客观的。这对物理科学的大多数解释来说可能是十分正确的，然而对生物科学的多数解释就并不全然正确。生物学家的发现和学说往往和我们社会的传统价值观念相冲突。例如，达尔文的老师塞吉威克（Sedgwick）就曾强烈反对过自然选择学说，因为它暗示了神所设计的论据将被否定并对世界作出唯物主义的解释。也就是说，据他看来，上帝将从对世界的秩序和适应的解释中被搬掉。生物学学说确实常常是充满价值观念的。这可以拿达尔文的共同祖先学说作为例子来说明，这个学说将人从在宇宙中占有独一无二的地位上拉了下来。最近关于“智商”（IQ）是否由遗传决定并且在多大程度上由遗传决定的争论（特别是和种族问题联系起来）以及关于社会生物学的争论都是恰当的例子。在所有这些情况中冲突都发生在某些科学发现或对这些发现的解释和某些传统的价值体系之间。不论科学研究是多么客观，它的发现所导致的结论往往是充满价值观念的。 文学评论早就觉察到某些科半家的著作对小说