Chapter 4 Chapter 3 Biology in Change-1

Rational background When writing a history of scientific thought, it is necessary to divide the science of a certain historical period into several main problems, and then track the evolution or development of each problem by time.This strictly topical approach has its merits, but it isolates each problem from other problems in the science of the time and from the overall cultural and intellectual context of the period.To remedy this serious deficiency, in this chapter I give a brief history of biology as a whole and try to relate it to the intellectual background of the time.Individual issues of biology are given special treatment in later chapters and should be studied against the overview of this chapter.It is also in this chapter to properly relate the relevant issues to functional biology (anatomy, physiology, embryology, behavior), since functional biology is not covered in this book.

Each age has its own "mood," or conceptual framework, which, while not consistent, influences thought and action in some way.The Athenian culture of the fourth and fifth centuries BC, most of the secular ideas of the Middle Ages, and the scientific revolution of the seventeenth century all had very different rational backgrounds.It would be a mistake, however, to think that any epoch has been dominated by a certain mode of thought, an ideology or system of interpretation, and eventually replaced by a new and often quite different conceptual structure.For example, in the 18th century, Linnaeus and his contemporary Buffon were completely different in rational conceptual structure.Two very different research traditions can co-exist, and their respective adherents work at odds with each other.For example, in the second half of the nineteenth century, the positivism of the physicists, based on essentialism, coexisted with the Darwinism of the naturalists, which was based on the idea of ​​populations and posed problems of adaptation that were embedded in the positivists' physics. Home seems meaningless.

3.1 Ancient It is not at all surprising that all primitive men are keen naturalists, since their existence depends on knowledge of nature.They must recognize potential enemies and sources of livelihood, and they are concerned with life and death, disease and fertility, "spirituality" and the distinction between man and other living things.Almost all primitive people in the world believe that everything in nature is "alive", even rocks, mountains, and the sky have gods.Divine power is part of nature, which itself is active and creative.All religions before Judaism were more or less animism, and their attitude towards God was completely different from the monotheism of Judaism.Ancient people's interpretation of the world was a direct result of belief in animism. (Sarton, 1927-1948; Thorndike 1958-1960).

There is reason to believe that there was some development in early science after this primitive state, but apart from some medical legends, we know nothing about biology in other pre-Hellenic cultures due to lack of data.There is also no evidence that anyone in ancient times attempted to explain the facts gathered. The great Greek epics of Homer and Hesiod vividly describe the "polytheism" of early Greece, which is in sharp contrast to the "monotheism" of Judaism, Christianity, and Islam.It appears that this polytheism favored the development of philosophy and early science.For the Greeks there was no single almighty God and no "revealed" Bible that would have allowed them to consider natural causes without blasphemy.Nor did Babylon, Egypt, or Israel have a powerful priestly class that monopolized thinking about the natural and supernatural.So there was nothing in Greece that prevented different thinkers from coming to different conclusions or explanations of these phenomena.

As far as Greek biology is concerned, we can list three main traditions.The first is the natural history tradition, which is based on knowledge of local fauna and flora as far back as prehuman times.Such knowledge is passed from generation to generation by oral language, and it may be well assured that only a very small part of it is provided by Aristotle's Zoology and Theo Phrastus' writings on plants.Knowledge about wild animals is invaluably supplemented in all cultures by the experience of keeping domestic animals.Individual behavior, birth, aging, illness, death and other biological phenomena of livestock and poultry are much easier to observe than wild animals; and because the life phenomena of animals are similar to human beings, this promotes comparative research.This made a positive contribution to the development of later anatomical and medical research.

The second Greek tradition is philosophy.The Greek philosophy of the Ionian philosophers Thales, Anaximander, Anaximenes and their disciples took a completely new view of natural phenomena, linking them to their causes and sources rather than consigning them to the soul , God, and other natural objects.In their quest for a unified concept that can account for many different phenomena, they often propose some ultimate cause or element (from which everything else is produced, such as water, air, land, and other things that cannot be named are called elements. ).These Ionian philosophers apparently drew on the knowledge and achievements of the Babylonians and other Near Eastern civilizations and adopted their interpretations of natural phenomena, especially non-living phenomena.The Ionians on the origin of biology.Their speculations did not have a long-term impact, what is more important is their views on human physiology.The real significance of the Ionian school is that it symbolizes the rise of science, that is to say, they explore the natural causes of natural phenomena.

The center of philosophical thought then moved to the Greek colonies in Sicily and southern Italy in the sixth and fifth centuries BC, where the most famous figures were Pythagoras, Xenophanes, Parmenides, and Empedocles.With his emphasis on numbers and quantities, Pythagoras created a powerful tradition that influenced not only the physical sciences but also biology. Empedocles seems to have been more concerned with biological phenomena than his predecessors, yet his writings have not survived.So far we only know that he proposed four elements: fire, air, water, and land.According to his opinion, the entire material world is composed of these four elements in different combinations, and various forms are formed due to the different combinations.homogeneity and heterogeneity.The belief about the four elements has lasted for more than two thousand years, and the question of homogeneity and heterogeneity was brought up by the zoologist KEvon Baer and the philosopher Spencer in the nineteenth century.

Two notable schools of philosophy arose in the ensuing years: the school of Heraclitus, which emphasized change (“everything in the world is constantly changing”); the school of Democritus (whose I am the founder of atomism), emphasizing the invariance of atoms, and atoms are the smallest unit of all objects.Democritus appears to have written a great deal (although little survived) on biology, and some of Aristotle's ideas are thought to have been borrowed from him.For the first time, Democritus raised the question: due to the structure of the atom, are natural phenomena, especially those in the biological world, purely technical or purely by chance?

The question divided philosophers as soon as it was posed, and chance or necessity has been one of the subjects of debate among philosophers ever since (only a few years ago Monod (1970) used it for a book he wrote title of the book). More than two thousand years later, Darwin pointed out that there are not only two kinds of freedom of choice, chance and necessity, and the two-step process of natural selection avoids the dilemma of Democritus. These early Greek philosophers had long recognized that everyday physiological phenomena such as movement, nutrition, sensation, reproduction, etc. needed to be explained.What surprises the modern student is that the Greek philosophers should have thought that single-minded reflection could account for each of the above phenomena.Admittedly, in the times in which they lived this was probably the only way to go.The situation then slowly changed, especially when experimental science began to be freed from philosophy in the late Middle Ages and Renaissance.

The tradition of providing scientific explanations purely through philosophical thinking has continued for a long time, and it has had an increasingly serious adverse effect on scientific research in the eighteenth and nineteenth centuries, causing Helmholtz to sharply criticize the tyranny of philosophers.These philosophers rejected his experimental findings simply because they did not fit with their deductive reasoning.The same attitude is adopted by essentialist philosophers who reject Darwin's theory.However, the philosophical method of deductive reasoning in ancient Greece is conducive to raising some questions that have never been raised before, and making these questions more accurate and systematic, thus clearing the way for pure scientific research methods, and finally replacing them. Philosophized (philosophical reasoning).

A third ancient tradition, the biomedical tradition of the Hippocratic school, coexisted with the above-mentioned natural history and philosophy traditions.The biomedical tradition has unearthed a vast body of knowledge and theory in anatomy and physiology.This knowledge, in turn, was further developed by Herophilus of Alexandria, Erasistratus, and by Galen and his school, forming the basis for the revival of anatomy and physiology during the Renaissance, especially in the Italian school.The study of human anatomy and physiology was the focus of attention in biology after Aristotle until the 18th century.In science as a whole, however, the development of philosophy is far more important in the whole field of Western thought than the specific discoveries of anatomy and physiology. More than any other, two Greek philosophers, Plato and Aristotle, influenced the subsequent development of science.Plato (c. 427-347 BC) was particularly interested in geometry, which had a huge influence on his thinking. His observation that a triangle is always a triangle no matter how its three corners are composed, discontinuously different from a quadrilateral or other polygons, formed the basis of his essentialist thinking.Essentialism is a philosophy that is very incompatible with biology.It took more than two thousand years for biology to get rid of the shackles of essentialism under the influence of Darwin.Since Plato's thought was rooted in geometry, it is not surprising that he made little use of the naturalist methods of observation.In his book "Timaeus" (Timaeus), he openly declared that real knowledge cannot be obtained through sensory observation, but only the enjoyment of eye sight.He placed particular emphasis on soul and design (creator, demiurge), and thus came into contact through the Neoplatonists with the Christian dogma that dominated Western thought until the seventeenth century.Plato is undoubtedly important in the history of philosophy, but I must say that for biology he was a disaster.His ill-conceived concepts had a detrimental effect on biology for centuries.The rise of modern biological thought is partly the result of the emancipation from Plato's thinking. With Aristotle the situation is very different. Before Darwin no one contributed more to our understanding of the living world than Aristotle (384-322 BC).His knowledge of biology is extensive and his knowledge comes from a wide variety of sources.He worked as a physician's apprentice as a teenager, and later spent three years living on Lesbos Island, spending a lot of time studying marine life.Almost every aspect of the history of biology begins with Aristotle.He was the first person to classify biology and wrote special works for it (such as animal classification, animal reproduction, etc.), he first discovered the heuristic significance of comparative law and is rightfully called comparative law. founder of law.He was also the first person to detail the life histories of many species of animals.He wrote the first book on reproductive biology and life history.He pays particular attention to the phenomenon of biodiversity and the significance of the distinctions between plants and animals.Although he did not propose a formal classification (method), he classified animals according to certain standards, and his classification of invertebrates was more reasonable than that of Linnaeus two thousand years later.In physiology he mostly adopted the traditional view and was not brilliant.Compared with his predecessors, he is a staunch empiricist.His inferences are always rooted in his past observations.In his article "Animal Reproduction" (De generatione animalium 760b28), he clearly stated that the information (knowledge) obtained from the senses is the first, surpassing the information that rational thinking can provide.In this respect he is quite different from the Aristotelians among the scholastics, who believed that everything can be deduced by reasoning alone. The remarkable feature of Aristotle is to investigate the cause. He was not satisfied with just asking the question of "how", but also asked the question of "why", which was very remarkable at that time.Why do organisms develop from a fertilized egg to a full adult?Why are there so many purpose-directed activities and behaviors in the biological world?He clearly understood that the mere raw material from which a body is composed does not possess the capacity to develop into a complex organism.There must be something extra there, which he calls eidos.Completely different from Plato's definition, Aristotle's eidos is the principle of program purposiveness. In his thinking, the meaning of this word is exactly the same as that expressed by the genetic program of modern biologists.Contrary to Plato, who believed that there is an external force used to explain the order of nature, especially its tendency to complexity and achievement of goals, Aristotle believed that natural objects act according to their own nature, and all Natural phenomena are all processes of action or manifestations of processes.Since any process has a purpose, he considered the study of purpose to be an essential part of the study of nature.For Aristotle, therefore, all structure and biological activity has a biological or, as we now say, an adaptive meaning.One of the main purposes of Aristotle is to explain these meanings.Aristotle's "why" question plays an important role in the history of biology. . "Why?" is the most important question evolutionary biologists ask in their research. There are four assumptions about the origin and nature of the world: (1) a static world of short duration (the world created by Judeo-Christianity); (2) a static world of infinite duration (Aristotle's worldview); (3) A cyclically changing world, with periods of prosperity and decline; (4) a world of gradual evolution (Lamarck, Darwin's point of view).Aristotle ruled out the idea of ​​evolution by insisting that the world was basically perfect. Aristotle's advanced thought has only been fully affirmed in recent decades.There are several reasons for his notoriety over the centuries.One reason was that the Thomists regarded him as their authoritative philosopher, and later when scholasticism fell into disrepute, Aristotle naturally followed suit.Another more important reason is that during the period of the scientific revolution in the sixteenth and seventeenth centuries almost all emphasis was placed on the physical sciences.Since Aristotle developed the famous philosophy of biology and unfortunately believed that the macrocosm and the microcosm can be viewed in the same way, people have applied his biological ideas to physics and cosmology.This had sad consequences, as Bacon, Descartes, and many other scholars repeatedly accused in the sixteenth, seventeenth, and eighteenth centuries.Considering that most of Aristotle's work is so good and creative, it is difficult to understand the various criticisms and ridicules these scholars have directed at him. To the extent that the biological sciences have been liberated from the physical sciences, so has the modern reappraisal of the importance of Aristotle grown.Only when the duality of the biological organism is now fully recognized is the blueprint for growth, development and function realized—the genetic program is equivalent to the formative-principle postulated by Aristotle.Philosophers and physicists have for centuries been deaf to the views of naturalists like Aristotle, who believed that in order to make a frog from an egg, and a chicken from an egg, more than physics was necessary. Laws are something more (Mayr, 1976).This does not require any sprites, all that is required is the acknowledgment that complex biological systems are the product of a genetic program that is more than three billion years old.There is nothing more likely to give rise to useless debate than the absurd claim that the macrocosm obeys the same laws as the microcosm.There is as yet no indication that this insight has reached most philosophers, but it is beginning to be recognized among biologists. Three Greek biological traditions continued to prevail after Aristotle.Natural history, especially the description and classification of plants, reached new heights in the writings of Theophrastus S and Dioscorides, while Pliny (23-79 AD) was interested in zoology and was an encyclopedic compiler.The biomedical tradition reached its peak with Galen (131-200 AD), and his influence continued until the 19th century. In the philosophical world after Aristotle, there was a division between the Epicureans and the Stoics.Epicurus (342-271 B.C.) and his school based on Democritus' view that everything is made of unchanging atoms, which are constantly rotating and colliding with each other at random.Epicurus provided a thoughtful materialist interpretation of the living and non-living world, arguing that everything happens through natural causes.In situ life appears to be the result of the movement of inanimate matter.How life behaves depends on how well-configured atoms fit together, and his explanation is very modern. Lucretius (99-55 BC), one of his followers, was an equally uncompromising atomistic materialist.Both of them opposed Aristotle's teleological thought. Lucretius presents a well-reasoned argument against the concept of design.In addition, he published some arguments, which were mentioned again and again in the eighteenth and nineteenth centuries.Yet he also vigorously defended Aristotle while criticizing certain atomists who believed that the lion and the oak tree could be produced by the accidental interaction of water and fire.In this regard, Galen agreed with him. The Epicurean argument was primarily directed against the Stoics, who espouse pantheism (polytheism) and the belief that the world was designed and created for the benefit of mankind.According to their views, the purpose of philosophy is to know and understand the order of the world, and later natural theology was derived from the Stoic school.The Stoics do not recognize chance as a factor in the world; they believe that everything is purposeful and deterministic.They were strictly anthropocentric, emphasizing the distinction between intelligent humans and instinct-driven animals (Pohlenz, 1948). After Lucretius and Galen and up until the Renaissance, no really meaningful state of affairs occurred in biology. As far as I know, the Arabs have made no important contributions to biology, even two famous Arab scholars who were very interested in biology, Avicenna (980-1037) and Aberrhos (Ibn Rosh, 1120-1198). However, the rediscovery of Aristotle in the Western world through the Arab translation is probably the greatest contribution made by the Arabs to the history of biology, and other contributions are more indirect.The Greeks were great thinkers, but they didn't value experimentation. (Regenbogen, 1931).In contrast, the Arabs were great experimenters, and it can even be said that they laid the foundation for the later experimental science.However, the journey to this final goal is extremely tortuous, and metallurgy is the most important intermediate station. 3.2 The Christian Worldview After Christianity conquered the West, the Greek idea of ​​an eternal, largely static world was replaced by an entirely new one.Christian theology is governed by the concept that God created the world.According to the Bible, the world was newly created and all knowledge about the world is contained in the Bible.This dogma precludes the necessity and possibility of asking "why" questions, or digs out the roots of any evolutionary thinking.The world created by God was, as Leibniz later put it, "the most perfect of all possible worlds."Man's attitude toward nature is governed by the will of God, which is "to be fruitful and multiply, and to fill and subdue the earth; and to have dominion over the fish of the sea, and the birds of the air, and every living thing that moves on the earth." (Genesis 1:28) Nature is subordinate to and serves man; the unique God in Judaism or Christianity is not at all the same thing as reflected in the traditional Buddhist beliefs felt by pantheists.The present respect for the environment is alien and alien to the "monotheistic" religions of the Near East. As far as biology is concerned, Christianity has had nothing more important in its development than a worldview called natural theology.In the writings of early Christian writers, nature is sometimes compared to a book, the natural counterpart of the Christian Bible.The equivalence of these two books suggests that the study of nature should have natural theology as a complement to revealed theology in Scripture. Christian natural theology is not a new concept.The harmony of the world and the complete adaptation in appearance of the world of life amazed many observers of nature long before the rise of Christianity.More than 2,000 years before the Greeks and Hebrews, in the ancient Egyptian empire (Memphis), it was suggested that natural phenomena were designed by supernatural beings.More explicit theological statements can be found in the writings of the Greek historians Herodotus and Xenophon.Plato sees the world as being created by a wise, good, rational and extraordinary technician.The Persian school of thought that the earth is designed to be an environment suitable for living things was further developed and enriched.Galen also strongly supported the notion that the world was designed by a Creator.But no one was more important in the development of natural theology than Saint Thomas Aquinas.Through the influence of his writings, the theological world view has become the dominant thought in the western thought circle.In his work (Summary of Theology, Summa theologiae) he argued for the existence of God in terms of the order and harmony of the world (which required an intelligent god to direct all natural things to their ends). Despite the preaching of natural theology, the age of scholasticism was still unfavorable to the development of natural science.Scholastics were rationalists (rationalists) who judged truth by logic rather than by observation or experiment (hence their verbosity).Propaganda and the search for truth are the prerogatives of the clergy.In general, both the study of natural objects and empirical methods were discriminated against at the time.The dominant philosophical thought of scholasticism was Thomism, which Aquinas believed came primarily from Aristotle.Oddly enough this philosophy is called realism which is misleading. For a modern biologist, the most distinctive feature of realism is its unconditional support for essentialism.Nominalism is the only other influential school of scholasticism, which emphasizes that only individuals really exist, and individuals are grouped together by names to form categories.Nominalism had no influence on biology in the Middle Ages, and it remains unclear whether or to what extent it contributed to the eventual rise of empiricism and population thinking. The Christian church concept of the absolute authority of the Bible was inexplicably extended to other writings during the Middle Ages, notably those of Aristotle and those of Arabic scholars such as Avicenna.When the question of how many teeth a horse has is debated, the answer is not found in the horse's mouth but in the writings of Aristotle.The introversion of medieval Christianity paid little attention to the natural world.This situation began to change in the twelfth and thirteenth centuries. Hildegard (1098-1179) and Albertus Magnus (1193-1280) have written some works on natural history, but it cannot be compared with Frederick's (1194-1250) famous book De arte venandi. The book was centuries ahead of its time in the study of the morphology and biology of birds. (Stresemann, 1975). Frederick's influence was manifold; he translated parts of Aristotle into Latin and was the guardian of the Faculty of Medicine (founded 1150) in Salerno (Italy), which performed the first human dissections. Starting from Salerno, universities were successively established in some parts of Europe, especially in Italy (Bologna, Padua), France (Paris, Montpellier), and England (Oxford, Cambridge).The backgrounds of these schools vary, and some developed from medical schools, law schools or other schools, such as the Sorbonne (founded around 1200) which later developed into the University of Paris.Many of these universities soon became centers of scholasticism, and there has been debate whether their existence was a curse or a blessing to Western academic thought.They eventually became strongholds of progressive scholars in some fields, such as anatomy.As far as biology as a whole is concerned, universities did not become centers of biological research until the end of the 18th century and the beginning of the 19th century. There was a remarkable resurgence in logic, cosmology, and physics in the late medieval period (Crombie, 1952), whose academic excellence has only been re-evaluated in recent decades.By contrast, biology remains dormant.Only problems related to medicine and human biology were paid attention to, while more in-depth research on life phenomena that were of great fascination for the next few hundred years and modern biology was ignored.It has been suggested that this state of indifference had something to do with the extreme piety and devotion of that period, to which the myth of God's creation could not leave the slightest doubt.Yet this begs the question of why this taboo has not spilled over into physics and cosmology.Is it because the authority of mathematics and its neutrality to theology leads spontaneously to physics and cosmology, while biology lacks such a beginning that can gradually expand its role?Although natural theology finally provided this breakthrough, it did not bear fruit until the seventeenth century.Was it due to the discovery of foreign countries, which, though under the same celestial radiance and subject to the same laws of physics as Europe, had an entirely different fauna and flora?Is it because the study of living phenomena requires asking more profound and subtle questions than the study of free fall?The time lag between the renaissance of mechanical science and the resurgence of biology after the Middle Ages remains unanalyzed and unexplained. 3.3 Renaissance A new interest in natural history and anatomy arose during the Renaissance.Both are part of medicine in a sense, and most of the enthusiastic researchers are professors of medicine or practicing doctors. The study of medicinal plants was widespread throughout the second half of the Middle Ages, as reflected in the number of herbal books, especially after the resurgence of the writings of Theophrastus and Dioscorides.But it was mainly the flora of Brunfels, Bock, Fuehs that foreshadowed the "back to nature" movement in plant studies.The effect of travel is ultimately also felt for its liberating effect.This began with the Crusades, followed by the expeditions of Venetian merchants (such as Marco Polo to China) and the voyages of Portuguese sailors, and finally reflected in the discovery of the New World by Columbus (1492).One of the defining achievements of these travels was the sudden discovery of the vast diversity of flora and fauna that spans the globe.This achievement led to the publication of several encyclopedic works such as Wotton, Gesner, Aldrovondi's Natural History, Belon's Ornithology, Rondelet's Marine Biology, and others. Anatomy was taught in medieval medical schools (especially in Italy and France) in a special book-like fashion; the professor of medicine recited Galen, and the assistants ("surgeons") dissected the corresponding parts of the cadaver.This teaching method is terrible, the professor's lectures and arguments are simply repeating or explaining Galen, and it is considered that this is much more important than the actual dissection.It was Andreas Vesalius (1514-1564) who completely changed this approach.He himself took an active part in dissection and invented new dissection tools, and finally published the wonderfully illustrated Anatomy of the Human Body (De Humani Cornoris Fabrica. 1543).In this book he corrected many of Galen's mistakes, but he himself made very limited new discoveries and still retained the Aristotle format in physiological explanations.Nonetheless, Visanius ushered in a new era in anatomy, shifting from relying on traditional textbooks to relying on personal observation.His successors, including Fallopio, Fab-ricius ab Aquadepente, Eustacchi, Cesalpino, and Severino, not only made important discoveries in human anatomy, but some of them also made important contributions to comparative anatomy and embryology.What is particularly important about this development is that it provided the conditions for the rise of physiology. Applied science, that is, engineering, paved the way for a whole new way of looking at things during the Renaissance.The mechanization of worldview reached its first peak in the thought of Galileo (1564-1642) and his pupils.In their view, nature (the world) is a moving material system governed by laws.Movement is the gist and core of all things, and all things must have their mechanical (sexual) reasons.Galileo's emphasis on and emphasis on quantification (quantification) is reflected in his motto: "Measure everything that can be measured, and make what cannot be measured measurable."This led to the development and application of instruments to determine quantities; to the calculation of normal conditions to establish general laws; and to the determination that in scientific research one should rely on observation and experiment—rather than on authoritative phrases.This meant specifically denying certain aspects of Aristotelianism which had become so authoritative through the influence of the Thomists. The blame for Aristotle comes not only from physicists but also from philosophers.Francis Bacon was particularly active against Aristotelianism and was the founder of induction, although his own biology was entirely deductive.Bacon's great achievement lies in his endless challenge to authority, and his emphasis on the incompleteness of people's knowledge, which is the opposite of the completeness of people's knowledge in the Middle Ages. As far as biology is concerned, the most positive contribution of the scientific revolution has been a new attitude to research.This attitude completely negates scholasticism, which seeks truth only by logic.More emphasis on experimentation and observation, that is, more emphasis on gathering facts.This is conducive to the use of natural laws to explain natural phenomena, and discovering natural laws (laws) is the task of scientists. The mechanistic view made few specific contributions to biology, including Harvey's determination of blood volume (an important link in his demonstration of the circulation of the blood) and the work of some anatomists, notably Giovanni Alfonso Borelli (1608-1679) on Action research.Movements of limbs, joints and muscles are best suited for mechanical (sexual) analysis. The publication (1687) of Newton's Principia (Mathematical) greatly strengthened the mechanistic view of physiology ("Principles" mechanically explain the entire non-biological world on a mathematical basis).At that time, it was most fashionable to explain everything according to the force and motion of physics. Although it was not appropriate to explain biological phenomena in this way, it was still explained in this way.For example, the phenomenon of warm blood in mammals and birds is explained by the friction of blood in blood vessels and has been circulating for about 150 years.Although a few simple experiments or observations of the circulation of the blood in amphibians and fish the size of a mouse or a bird would disprove this notion.Such flippant interpretations of physics were a serious obstacle to biological research in the seventeenth and eighteenth centuries (and even into the nineteenth). Radl (1913: viii) pointed out long ago that the victory of the physical sciences during the scientific revolution was in many ways a blow to biology and had a damaging effect on some unique biological ways of thinking (until the nineteenth, These ways of thinking were re-adopted in the twentieth century), such as procedural purposiveness (reduced to the search for ultimate causes), systems thinking, the study of properties, emergent properties, and historical development, etc.All of these are not opposed, ridiculed or discriminated against.Biological scientists respond to such attacks by physical scientists in two ways, one is to describe biological processes in the language of physicists ("motion and force"), and the other is to use vitalism as a safe haven to explain natural forces. .Both approaches are futile.Only recently have biologists been intellectually powerful enough to develop an explanatory model that takes into account the uniqueness of the living world and is consistent with the laws of chemistry and physics. (see Chapter 1). Probably no one has done more to spread the mechanistic worldview than the philosopher Rene Descartes (1596–1650).和柏拉图相似，他的思想受数学影响很深，他最出色的贡献可能是发明了解析几何。他对亚里斯多德的宇宙学的非难既合理而又具有建设性，虽然他的主张最后也没有取得胜利。他将有机体简化还原为一类自动机的意见触怒了哪怕对生物体略有了解的每一位生物学家，因而遇到了激烈的反对。这对立的意见也通常是以同样荒唐的活力论表现出来。法国这个国家既有像从笛卡尔到La Mettrie、Holbach这样一些极端的机械论者。同时又可能是活力论最活跃的中心，这也许并不是偶然的巧合。 笛卡尔声称有机体仅仅是自动机，人类和有机体的区别是人有灵魂；他还认为一切科学都必须以数学为基础；以及他的其它一些武断的说法，虽然后来证明是错误的，却给生物学套上了枷锁，一直到19世纪末期。笛卡尔思想中最薄弱的一环涉及到起源。他认为有机体是由微粒偶然地碰在一起而形成的。这最终意味着应当用盲目的偶然事件的结果来解释自然。这种论点显然是和博物学者所论证的、自然的秩序性以及一切生物的非凡适应性相抵触。 关于笛卡尔最令人惊讶的是，尽管他本人否认，他的多数理论结构却是托马斯主义的。他的思想方法可以用他对自己的存在所作的论断充分说明：“我的结论是，我是一个物体，其全部精华在于思想，它的存在既不取决于它在空间的位置，也不依赖任何物质的东西。因此自我，或宁可说灵魂，借助于它我才是我，是和躯体完全不同的，是确实比躯体更容易了解，而且即使躯体不复存在，它也不会不再是它。”（《方法论》，Discourse onMethod，P．4）。他的多数关于生理学的结论不是通过实验或观察而是按演绎法推论而得。和在他以前的柏拉图相仿，笛卡尔是由于他的方法失效才论证了生物学问题不能通过数学推理解决。笛卡尔对随后生物学发展的影响，特别是在法国的影响，还有许多问题需要进一步研究。这包括笛卡尔主义在多大程度上影响了法国在以后的几百年中对进化思想（例如对拉马克）的漠视和冷遇。从现在看来，特别突出的是为什么笛卡尔及其某些追随者（如布丰）竟然如此幼稚对最简单的纯物理学解释也欣然接受，并作出结论：“一种单独的力（即地心引力）是一切非生物现象的原因，这种力和效结合就产生了有生命的分子，有机体的效能就由这些分子决定”（《哲学文集》Oeuvr，phil,：41）。 也许生物学必须通过这样一个阶段，在这个阶段中笛卡尔的有害无益的物理主义盛行无阻。亚里斯多德的完全正确的论证（生物不能仅仅只按无机物来理解）不幸被经院哲学庸俗化了，它用基督教教条的灵魂取代了亚里斯多德的本意。亚里斯多德——盖伦的生理学如按基督教的灵魂来解释确实在科学上是不能接受的。在这种情况下笛卡尔有两种选择。他或者转回到亚里斯多德的“形式”并重新给它下定义，就像现代生物学家在其遗传程序中那样做的一样，他或者可以完全扔掉基督教的灵魂（就动物而言），并且不用任何东西代替它，这样有机体就只剩下无机物，和其它无机物一样。笛卡尔选择了后者，这种选择显然是任何生物学家都无法接受的，因为他知道生物并不仅仅只是无机物。笛卡尔并不是一个生物学家，因而也并不作如此想。只是当他仔细考虑到人时，笛卡尔才认识到他的论点行不通。然后他就采取了在躯体与灵魂之间的二元论，从此以后这种二元论（笛长儿早就知道）就一直折磨着我们。 机械论世界观的统治并不是绝对的。伽利略学派和笛卡尔学派的极端主张几乎立即就激起了许多相抗衡的运动或动向，其中有两种在生物学史上最为重要：一种是性质——化学传统的兴起，另一种是多样性的研究。这两种运动都部分地植根于科学革命。 生理学在16世纪有一种新动向，即注意性质与化学组成而不是运动和力。这种观点在原则上决不是反物理主义的，因为它运用来解释生命过程的概念、定律、机制原先就是在解释非生物界过程中发展起来的。这一运动或动向的代表人物有Paracelsus（1493－1541）及其门徒，炼金术士以及通常称为医疗化学家的学派。虽然这种新动向在一开始希望就是不大的，而且还有不少错误，但是从长远看它对生物性过程的解释远比严格机械论具有更持久的影响。Paracelsus既是一个天才，又是一位庸医，他相信巫术和起自然力；他否认希腊传统的四种元素的重要性而代之以具体的化学药品，特别是硫、汞及盐类。他将生命过程看作是化学过程的新概念开拓了一个全新的传统，并经由JH．vanHelmont（1577一1644）在生理学历史土开创了一个新阶段。在van Helmont的着作中我们看到的是迷信、活力论以及非常出色的观察混在一起的一种奇怪混合物。他新创了“气体”（gas）这个词并对二氧化碳进行了卓越的研究。他确认了胃的酸性和小肠的碱性从而开拓了营养生物学的新研究领放。他将生理学化学化的这种努力通过他的追随者（如Stahl）延续了下来。 3．4多样性的发现 对一切现象作出机械论解释的目的之一是为了进一步推进科学的统一。物理科学家的抱负或野心是将宇宙间的现象简化还原成最小数量的定律。由于发现了动物和植物的几乎毫无限制的多样性以后，在研究生物有机体方面孕育着一种几乎正好相反的趋势或倾向。草药医生和百科全书编辑人复活了Theophrastus和亚里斯多德的传统，发现并忠实地描述了各种各样的生物。越来越多地博物学家投身干自然界多样性研究并发现世界万物远比想像的要丰富得多。上帝的荣耀可由她所创造的万物来研究，从最低等的一直到犀牛和大象。 科学革命也不谋而合地为多样性研究创造了条件。各种新仪器的开发制造就是机械化思想的产物之一，其中对生物学家最重要的是显微镜。它为生物学家开辟了一个新天地。尽管最早的显微镜只能放大十倍，但这就已经足够显示出完全未曾料想到的活的微观世界的存在，特别是肉眼看不见的水生生物。 列文虎克（Anton van Leeuwenhoek，1632－1723）和马尔丕基（MarcelloMalpishi，1628－1694）是早期使用显微镜的两位着名人物。他们描述了动植物组织（组织学的开端），并发现了淡水浮游生物，血细胞甚至精子。早期使用显微镜的人的研究特点是单纯地为了发现，发现是一种享受，一种欢乐。他们没有目的地去观察任何可以放大的物体并就观察所见加以描述。在他们的着作中很少能找到生物学学说。顺便说一句，三百年以后，最初使用电子显微镜时也是这样。 也就在这个时期发现昆虫是科学研究的很好题材。雷迪（Francesco Redi）于1668年证明昆虫并不是自然发生的产物而是由受精后的雌虫排出的卵发育而成。JanSwammerdam（1637－1680）就蜜蜂和其它昆虫作了极其出色的解剖研究。十七，十八世纪对昆虫研究作出重要贡献的博物学家还有Pierre Lyonn－et，Ferchault de Reaumur，de Serres，Leonhard Frisch，Roesel von Rosenhof。他们之中有不少人完全是由于描述所发现的新事物的欣喜心情而从事昆虫研究，哪怕是毛虫有4041条肌肉（Lyonnet，1762。参阅第四章）这样的研究。 由于航海家和探险家从世界各地带回了外国的各种各样新奇的动植物，这样就进一步促进了研究生物多样性的热情。柯克船长在一次航行中邀请了博物学家福斯特父子参加。小福斯特影响了亨伯特（Alexander von Humboldt），后者又鼓舞了年轻的达尔文。 在海外旅行和探险的时代发生了对外国各种动植物如疯似颠的着迷情景并促使建立了丰富的收藏，如林奈在荷兰，班克斯在伦敦，布丰在巴黎。 收藏品的指数式增长引出了当时最紧迫的问题：分类。由切查皮诺（Cesalpino），悌宇列弗（Tournefort），以及瑞（John Ray，关于他的研究工作将在第四章介绍）开始，到林奈（1707—1778）时达到了分类学时代的顶峰。林奈的重要性在其一生中都被抬高到超过从亚里斯多德以来的所有博物学家。然而一百年以后他却被贬低为“返祖” 到经院哲学时期的腐儒。我们现在将他看作是他的那个时代的产物，在某些方面很突出，在另一些方面则又很轻率无知。作为一个当地的博物学家，他和在他以前的瑞一样，观察到物种之间非常明确的不连续性并设想到从一个种转化成另一个种是不可能的。最低限度在他的早期着作中，他坚持种的恒定性和种的划界，这就为以后进化学说的发展创造了条件。只是近年来人们才又记起了林奈在植物地理学和生态学方面作出的贡献。遗憾的是林奈的许多追随者缺乏他那样的才智，在描述新种时就认为是最大的满足。 那个时期的博物学家并不是全都醉心于种的描述。例如克尔路德（Kolreuter，1733－1806）虽然起初是由于对物种本质的传统兴趣脱颖而出，却在遗传学，受精作用以及花的生物学上都作出了开拓性的贡献。这些研究经由C·K·Sprengel（1750－1816）通过植物受精作用的大量实验而得到延伸。这两位科学家的工作虽然在他们生前基本被忽视，却是后来达尔文对植物的受精作用（及生殖力）实验研究的一部分基础。 博物学中和林奈传统十分不同的另一传统是由布丰创始的，他的《自然历史》 （1749ff）实际上是当时每个受过教育的欧洲人都读过的。这本书侧重动物及其生活史，对博物学研究产生了重大冲击，然而这一冲击在现代行为学和生态学之前并没有结出丰硕的果实。博物学研究在18世纪和19世纪早期几乎完全是由业余爱好者，特别是教区牧师（如Zorn，White，C·L·Brehm等）进行。布丰作为一个杰出的普及宣传者，他的最大影响可能是通过他那鼓动性的、往往是大胆的新奇思想来实现的。他对当时的思想起到了极大的解放作用，诸如宇宙学，胚胎发育、物种，自然系统以及地球起源等等广泛领域都是如此。他并没有能够提出进化学说，但无疑为拉马克准备好了舞台（参阅第七章）。我完全同意Nordenskiold对布丰的评价（1928：229）：“在纯粹的理论领域中，他是18世纪最杰出的生物学家，他具有最雄厚的思想财富，对随后的年代真正有益而且会对将来产生影响。” 多样性当然是完全不符合牛顿模式物理定律的一种现象。然而由于定律是制造定律的创造者存在的证据，所以发现规定多样性的定律就成为对多样性的研究者的挑战，从Kielmayer到五元论者再到阿伽西。为了发现这样的定律所作的努力大都违背了研究者的心愿，却为进化提供了大量证据。 实际上林奈建立了系统学这门科学而布丰则使博物学的研究成为每个人的消遣。由于Haller使生理学达到了新的高度，胚胎学也由于Bonnet及Wolff达到新的水平。因此，在17世纪被物理科学掩盖而大大失色的生物学在18世纪中叶就开始显露出自己的本来面目。 18世纪生物学的主要兴趣很明显是生物有机体的描述、比较和分类。解剖学从一开始主要是生物学研究的一种方法，这时也日益重视比较解剖研究，并发展成为研究多样性的一种方法。比较法作为科学上的两种主要方法之一（另一种是实验法）在18世纪的后半期才真正开始发挥效能。的确，比较研究自从16世纪已有Belon，Fabrizto，Severino等人进行过，但作为一种系统的研究方法则只是从Camper，Hunter，Pallas，Daubenton，特别是Vicq－dAzyr才开始。这样建立起来的新传统在居维叶的工作中达到第一次高潮，他在一系列的方法学研究中，特别着重在无脊椎动物方面，论证了在动物的主要门类之间不存在任何过渡动物，从而根本否定了“自然界阶梯”的存在。1859年以后比较解剖研究为达尔文的共同祖先学说提供了一些最有说服力的有利证据。 现代的人很难理解为什么科学和基督教从文艺复兴直到18世纪能够和谐共存。这原因是科学和神学在那个时候已综合成自然神学（物理神学），成为了当时的科学。自然神学家为了神学而研究创世主的创造。自然（界）对他来说正好是上帝存在的最有说服力的证据，否则怎样能解释世界万物的和谐与有目的性？这就证明研究自然是正当合理的，而这种研究，特别在17世纪，是不够自觉的。自然神学的幽灵一直支配着莱布尼茨、林奈、Herder这些学者和英国的科学，直到19世纪中叶。科学史家对自然神学概念全面统治一切科学思想与活动的情况早就了解，并有很多颇有见地的论述。 机械论世界观使研究自然的博物学家感到左右为难。如果他追随物理科学家的主张，他就必须承认世界是一次造成的，而且就在同时建立起自然规律（“第二位原因”），这样就在随后的阶段中上帝就不需要作更多的干预。“自然哲学家”的任务是研究神的规律所由以表现的近期原因。这种解释非常适合物理世界的现象，但和生物界现象则完全矛盾。在生物界中个体的活动和相互作用是如此的多种多样，不可能想像能够用有限数量的基本定律加以解释。生物界的每一事态是如此的不可预测，如此特殊和如此独特以致观察这些事态的博物学家发现必须求助于造物主上帝，并在每一种生物的每一个个体的每一生命活动的细节上求助于上帝的思想和行动。然而看来这同样也是不可想像的。 因为，这正如一位评论家所说的，一个监工只监督他管理的工人，并不干每个工人干的活。这样一来两种选择看来都行不通，博物学家便陷于左右为难的困境。此后两百年中人们一直试图努力摆脱这种困境，但在神造论（特创论）教条的框架桎梏下无法摆脱。 因此，这两个学派就继续存在了下来：物理科学家从上帝看出了上帝在创造天地万物时就制定了管理这个世界一切过程的规律；对比之下博物学家在研究生物世界时则认为，就生物界的多样性和适应性来说，伽利略和牛顿的基本定律毫无意义。更正确地说，他们从上帝看不出丝毫的多样性或适应性。瑞（Ray）写的《上帝创造万物与上帝的智慧》 （The Wisdom of God Ma－nifested in the works of the Creation，1691）一书不仅是对“设计论”的强有力批判，而且是一本很好的博物学，甚至可以说是最早的一本生态学。博物学家-神学家的着作所依据的绝妙观察使这些着作得以广泛流行并促进了博物学研究的发展。由于设计论是在一个静止的“被创造”的世界中对适应现象的唯一可能解释，因而自然神学的出现便是必然的。在博物学的这个早期阶段任何新的发现都对自然神学有利。想象上的热带居民的牧歌式生活特别被看作是上帝的天佑设计的证据。 纤毛虫和植物形动物的发现；似乎证实了一直到人类的伟大链索。然而自然神学的胜利时辰是短暂的。它在布丰的许多文章中都遭到含蓄的质疑，而在休谟的《对话录》 （Dialogues，1779）以及康德的《判断力批判》（Critique of Judgment，1790）中则受到公开的批评。 进化生物学的发展大大得益于自然神学。考虑到1859年以前进化思想丝毫不受重视，这看来是十分矛盾的说法却是真实的，虽然是在间接意义上。自然神学所提出的问题涉及到造物主的智慧以及他使各种生物彼此适应和使之与环境适应的高明技巧。这就导致了Reimarus及Kirby对动物本能的基础研究，并导致了C·K·Sprengel发现花对昆虫传粉的适应现象以及相应的传粉昆虫的适应。从瑞，Durham到Paly，到BridgewaterTreatises的作者以及其它许多同时代人，所有的自然神学家都对我们现在称之为适应的现象进行了阐述。当在解释中将“造物主之手”用“自然选择”代替时，就可以把关于生物有机体的绝大多数自然神学文献几乎只字不易地转变成进化生物学文献。没有人能够怀疑自然神学为进化生物学奠定了雄厚而又坚实的基础，随后一直到达尔文的时代才重新又像自然神学那样积极地对适应现象进行了研究。 自然神学代表了一种过份乐观的世界观。但在18世纪的后半期有不少事件破坏了这种无根据的乐观情绪。例如里斯本地震，法国大革命的恐怖以及对生存竞争激烈程度的认识。自然神学对西方世界思想的羁绊于18世纪末之前在法国和德国始告结束。奇怪的是，19世纪前半期它在英国又焕发青春。Paley的《自然神学》（1803）和BridgewaterTreatises（1832～1840）又重新强调提出对设计论的争论。当时英国主要的古生物学家和生物学家都是自然神学论者，包括查尔斯·莱伊尔（Charles Lyell）以及达尔文的其它朋友。这个事实说明了的大部分理性结构（参阅第九章）。 除博物学而外，从文艺复兴到19世纪生物有机体的研究大多掌握在医学界人士手中。 纵使着名的植物学家也是按医生培养的（Ray除外）。他们主要关心的当然是健康人或病人的躯体功能运行情况，其次是发生（generation）问题，即新有机体的起源。18世纪初生理学面临的任务是在更加极端的机械论和与之对立的彻底活力论之间求得妥协。 是Albrecht von Haller（1707～1777）为生理学指出了新方向。他转回到哈维和活体解剖学者的经验主义传统并试图通过许多动物试验来确定各种器官的功能。虽然他没有找到（指导生理活动的）“灵魂”的证据，但他的试验使他认识到活体的结构具有某些性质（如应激性）是无生物所缺少的。 即使有了Haller的不偏不倚结论，直到20世纪的头25年形势还是左右摇摆不定。活力论和机械论彼此继续斗争不已。例如活力论得到下列支持：（法国）蒙玻利埃学派（Bordeu，Barthez），德国的自然哲学派，Bichat，Claude Bernard，Driesch；而不妥协的机械论则得到下列人土的顶礼膜拜：Ludwig，duBoiS－Reymond，Julius Sachs，Jacques Loeb。可以这样说，这种争论一直没有完全停止过，直到认识到发育（development）的一切表现和生命都是由遗传程序所控为制止。 十七、十八世纪的另一个着名争议涉及到发育。要回答的问题是，一个“无定形” 的娃卵怎样发育成成娃？一个鱼卵怎样发育成鱼？先成论的扞卫者认为在卵中有某种预先形成的东西使青蛙的卵转变成青蛙，使鳟鱼的卵变化成鲜鱼。遗憾的是先成论学派的极端代表人物认为有一微型成体（雏形体）以某种形式被包罗在卵（或精子）中。这一假定的荒谬性是很容易证明的。他们的对手则持有渐成论（后生说）观点，即完全无定形的卵逐渐分化成为成体的器官。这一派也没有较大的说服力，因为他们不能说明发育过程的物种特异性便只得求助于活力。他们是活力论的领袖人物。在生物学史中情况往往就是这样：对立的两种学说中最后没有一种占压倒优势而是两者折衷地融合在一起。 渐成论者在谈到卵起初是未分化的，是正确的，先成论者在谈到发育是由某种先成的东西（现在认为是遗传程序）控制时也是正确的。参与这场论战的除Haller外，还应当提到Bonnet，Spallanzani，以及C·F·Wolff（Roe，1981）。 3．5启蒙运动与生物学 正像“启蒙运动”（Enlightenment）这个词所表示的那样，18世纪，自布丰、伏尔泰、卢梭到狄德罗、Condillac、Helve－tius及Condorcet，是一个理性解放的时代。 这个时代的主要信仰形式是自然神论。虽然开明的自然论神者承认上帝存在，但是他们却无从证明上帝是为了人类的利益而创造了世界。自然神论的上帝是至高无上的智慧，世界及其普遍秩序的创造者；通用并且不变的规律的传播者。自然神论的上帝和人大不相同，也不关心人。从自然神论经由不可知论再到彻底的无神论并不非常费力，很多思想家就是这样走过来的。 启蒙运动的时代是这样的一个时代，以往的信条，不论是神学信条、哲学信条，还是科学的信条都要接受无情的批判。然而法国政府（“国王”）对哲学家的迫害却告诫人们，哲学家们的很多学说不仅被认为是哲学学说，而且也是政治学说。 例如Condorcet的平等主义就是对阶级特权（封建主义）的反叛，丝毫没有涉及生物学方面。他只承认有三种不平等，即财富的，社会地位的，和教育的不平等，而没有顾及到天赋的差别。他认为只要财富、地位和教育三者都平等了就达到了完全平等。像自然选择或甚至进化的概念对于提倡这种毫不妥协的平均主义的人来说是毫无意义的。 应当注意的是，启蒙运动并不是一种纯粹同质的运动。不同的哲学家有多少，不同的观点也就有多少。