Unit Ten
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　　Do animals think? How could the earth show so many signs of design and purpose and yet be random? Our best scientists are heatedly debating both sides of these and other scientific questions. In the following essay, the author takes a look at science education and argues that as well ass telling students the facts and theories that have already been proved and accepted, science teacher should spend more time introducing their students to the many mysteries that remain unsolved and the arguments taking place between scientists. What better way, he argues, to stimulate their interest in thing scientific?

　　DEBATING THE UNKNOWABLE
　　Lewis Thomas
　　The greatest of all the accomplishment of twentieth-century science has been the discovery of human ignorance. We live, as never before, in puzzlement about nature, the universe, and ourselves most of all. It is a new experience for the species. A century ago, after the turbulence caused by Darwin and Wallace had subsided and the central idea of natural selection had been grasped and accepted, we thought we knew everything essential about evolution. In the eighteenth century there were no huge puzzles; human reason was all you needed in order to figure out the universe. And for most of the earlier centuries, the Church provided both the questions and the answers, neatly packaged. Now, for the first time in human history, we are catching glimpses of our incomprehension. We can still make up stories to explain the world, as we always have, but now the stories have to be confirmed and reconfirmed by experiment. This is the scientific method, and once started on this line we cannot turn back. We are obliged to grow up in skepticism, requiring proofs for every assertion about nature, and there is no way out except to move ahead and plug away, hoping for comprehension in the future but living in a condition of intellectual instability for the long time.
　　It is the admission of ignorance that leads to progress, not so much because the solving of a particular puzzle leads directly to a new piece of understanding but because the puzzle -- if it interests enough scientists -- leads to work. There is a similar phenomenon in entomology know as stigmergy, a term invented by Grasse, which means "to incite to work." When three or four termites are collected together in a chamber they wander about aimlessly, but when more termites are added, they begin to build. It is the presence of other termites, in sufficient numbers at close quarters, that produces the work: they pick up each other's fecal pellets and stack them in neat columns, and when the columns are precisely the right height, the termites reach across and turn the perfect arches that form the foundation of the termitarium. No single termite knows how to do any of this, but as soon as there are enough termites gathered together they become flawless architects, sensing their distances from each other although blind, building an immensely complicated structure with its own air-conditioning and humidity control. They work their lives away in this ecosystem built by themselves. The nearest thing to a termitarium that I can think of in human behavior is the making of language, which we do by keeping at each other all our lives, generation after generation, changing the structure by some sort of instinct.
　　Very little is understood about this kind of collective behavior. It is out of fashion these days to talk of "superorganisms", but there simply aren't enough reductionist details in hand to explain away the phenomenon of termites and other social insects: some very good guesses can be made about their chemical signaling systems, but the plain fact that they exhibit something like a collective intelligence is a mystery, or anyway an unsolved problem, that might contain important implications for social life in general. This mystery is the best introduction I can think of to biological science in college. It should be taught for its strangeness, and for the ambiguity of its meaning. It should be taught to premedical students, who need lessons early n their careers about the uncertainties in science.
　　College students, and for that matter high school students, should be exposed very early, perhaps at the outset, to the big arguments currently going on among scientists. Big arguments stimulate their interest, and with luck engage their absorbed attention. Few things in life are as engrossing as a good fight between highly trained and skilled adversaries. But the young students are told very little about the major disagreements of the day; they may be taught something about the arguments between Darwinians and their opponents a century ago, but they do not realize that similar disputes about other matters, many of them touching profound issues for our understanding of nature, are still going on and, indeed, are an essential feature of the scientific process. There is, I fear, a reluctance on the part of science teachers to talk about such things, based on the belief that before students can appreciate what the arguments are about they must learn and master the "fundamentals". I would be willing to see some experiments along this line, and I have in mind several examples of contemporary doctrinal dispute in which the drift of the argument can be readily perceived without deep or elaborate knowledge of the subject.
　　There is, for one, the problem of animal awareness. One school of ethologists devoted to the study of animal behavior has it that human beings are unique in the possession of consciousness, differing from al other creatures in being able to think things over, capitalize on past experience, and hazard informed guesses at the future. Other, "lower", animals (with possible exceptions made for chimpanzees, whales, and dolphins) cannot do such things with their minds; they live from moment to moment with brains that are programmed to respond, automatically or by conditioning, to contingencies in the environment, Behavioral psychologists believe that this automatic or conditioned response accounts for human mental activity as well, although they dislike that word "mental". On the other side are some ethologists who seems to be more generous-minded, who see no compelling reasons to doubt that animals in general are quite capable of real thinking and do quite a lot of it —— thinking that isn't as dense as human thinking, that is sparser because of the lack of language and the resultant lack of metaphors to help the thought along, but thinking nonetheless.
　　The point about this argument is not that one side or the other is in possession of a more powerful array of convincing facts; quite the opposite. There are not enough facts to sustain a genuine debate of any length; the question of animal awareness is an unsettled one.
　　Another debatable question arises when one contemplates the whole biosphere, the conjoined life of the earth. How could it have turned out to possess such stability and coherence, resembling as it does a sort of enormous developing embryo, with nothing but chance events to determine its emergence? Lovelock and Margulis, facing this problem, have proposed the Gaia Hypothesis, which is, in brief, that the earth is itself a form of life, "a complex entity involving the Earth's biosphere, atmosphere, oceans and soil; the totality constituting a feedback or cybernetic system which seeks an optimal physical and chemical environment for life on this planet." Lovelock postulates, in addition, that "the physical and chemical condition of the surface of the Earth, of the atmosphere, and of the oceans has been an is actively made fit and comfortable by the presence of life itself."
　　This notion is beginning to stir up a few signs of storm, and if it catches on, as I think it will, we will soon find the biological community split into fuming factions, one side saying that the evolved biosphere displays evidences of design and purpose, the other decrying such heresy. I believe that students should learn as much as they can about the argument.

　　One more current battle involving the unknown is between sociobiologists and antisociobiologists, and it is a marvel for students to behold. To observe, in open-mouthed astonishment, one group of highly intelligent, beautifully trained, knowledgeable, and imaginative scientists maintaining that all behavior, animal and human, is governed exclusively by genes, and another group of equally talented scientists asserting that all behaviors is set and determined by the environment or by culture, is an educational experience that no college student should be allowed to miss. The essential lesson to be learned has nothing to do with the relative validity of the facts underlying the argument. It is the argument itself that is the education: we do not yet know enough to settle such questions.

New Words生词：

debate
vt. argue about (sth.) with sb., discuss
n. a discussion about a subject on which people have different views
unknowable
a. beyond comprehension, esp. beyond human comprehension
puzzlement
n. bewilderment, perplexity
turbulence
n. agitation; great disturbance 骚动，纷乱
turbulent a.
subside
vi. sink to a lower or more normal level; become less
package
vt. wrap or seal in a container, wrappings, etc. to attract purchasers
glimpse
n. a quick view or look
incomprehension
n. lack of comprehension; inability to understand
reconfirm
vt. confirm anew
skepticism
n. a doubting state or habit of mind; doubt
assertion
n. a positive statement; firm declaration
assert
vt. state positively; declare firmly
instability
n. lack of firmness; being unstable
admission
n. (an) act of accepting the truth (of sth.)
entomology
n. the branch of zoology that deals with insects 昆虫学
incite
vt. cause or encourage sb. to a strong feeling or action; provoke
termite
n. an insect that looks somewhat like white ants and eats the wood of buildings and furniture 白蚁
fecal
a. having to do with feces (waste matter discharged from the intestines)粪便的，排泄物的
column
n. a long, thin, upright structure; pillar; post
arch
n. a curved structure capable of bearing the weight of the material above it 拱
termitarium
n. nest of termites
flawless
a. without a flaw; perfect
flaw
n. a fault or weakness that makes sth. imperfect 瑕疵
air-conditioning
n. the system that uses machines to control the temperature of the air in a room or building
humidity
n. moisture, esp. of the air 湿气；湿度
ecosystem
n. an ecological system which relates all the plants, animals and people in an area to their surroundings, considered as a whole 生态系（统）
fashion
n. the popular way of dressing or behaving at a certain time
superorganism
n. a group of organisms (as of social insects) that function as a social unit
reductionist
a. having to do with a procedure or theory that reduces complex data or phenomena to simple terms
reduction n.
insect
n. a small animal with six les, a body divided into three main parts, and often wings 昆虫
exhibit
vt. show demonstrate
mystery
n. sth. that is not known or understood
unsolved
a. not solved or explained
introduction
n. a written or spoken explanation at the beginning of a book or speech
ambiguity
n. the possibility of two or more meanings; vagueness 模棱两可；意义不明确
ambiguous
a. having more than one possible meaning, permitting more than one possible interpretation or explanation
premedical
a. preparing for the study of medicine
outset
n. the beginning
engross
vt. take up all of; absorb
engrossing
a. (not of a person) very interesting
adversary
n. a person or group to whom one is opposed; opponent or enemy
adverse
a. hostile; unfavorable
Darwinian
a. of Charles Darwin or his theory of evolution
dispute
n. a quarrel, disagreement
feature
n. an important part or quality
reluctance
n. unwillingness
reluctant a.
doctrinal
a. of or having to do with doctrine
doctrine
n. a principle or set of principles (esp. of a religious or political kind) that is taught 主义；教条，学说
readily
ad. without difficulty, easily; without delay, quickly
perceive
vt. become aware of by seeing, hearing, tasting, smelling or touching; get an understanding of
awareness
n. the quality or state of being aware
ethologist
n. a person who studies ethology (the individual and comparative study of animal behavior, including that of man) （个体）生态学家；行为学家
consciousness
n. the condition being aware and able to understand what is happening; awareness
creature
n. a living person or animal
capitalize
vi. (on) profit by; use to one's own advantage included
hazard
vt. venture; risk
exception
n. the fact of being left out; (a cause of) not being included
chimpanzee
n. a small African ape with dark hair黑猩猩
whale
n. a large sea animal that resembles fish but breathes air 鲸
dolphin
n. a sea animal that has a snout like a beak 海豚
contingency
n. a chance happening; uncertain event
automatic
a. done or produced by the body without thought or control
automatically ad.
dislike
vt. consider unpleasant; not like
generous
a. willing to give or share; unselfish 慷慨的
generous-minded a.
sparse
a. thin; thinly scattered
resultant
a. happening as an effect; resulting
metaphor
n. a figure of speech in which two things are compared without using "like" or "as"
nonetheless
ad. in spite of that; nevertheless
sustain
vt. maintain or keep (sth.) going; confirm
genuine
a. real or true; not false
unsettled
a. not yet settled
debatable
a. lending itself to formal debate; having strong points on both sides
biosphere
n. the part of the world in which life can exist 生命层；生物圈
conjoin
vt. cause to join together or unite
coherence
n. natural or reasonable connection; consistency 连贯；一致性
coherent a.
resemble
vt. be like or similar to
embryo
n. the young of any creature in its first state before birth, or before coming out of an egg 胚胎
emergence
n. the act or fact or emerging
entity
n. sth. That has a real and separate existence; being; existence 实体；存在
totality
n. the state of being whole; completeness
feedback
n. a process in which the factors that produce a result are themselves modified, corrected, strengthened, etc. by that result 反馈
cybernetic
a. of, relating to, or involving cybernetics （控制论）
optimal
a. most favorable; best
optimum
n., a.
postulate
vt. assume without proof as a basis of reasoning; take for granted
notion
n. an idea, belief or opinion in one's mind; concept
fume
vi. give off vapor, gas or smoke; show anger or irritation
faction
n. a group or party within a large group 派别
evolve
v. develop gradually by a long continuous process 演化
decry
vt. express strong disapproval; cry out against
heresy
n. a belief different from the accepted belief of a church, school, profession or other group 异教；异端
sociobiologist
n. one who studies the biological basis for animal and human social behavior
antisociobiologist n.
behold
vt. have in sight; see
astonishment
n. great surprise; amazement
astonish vt.
imaginative
a. having or showing a strong imagination
govern
vt. direct or manage; rule; control
Phrases & Expressions
move ahead
go forward
plug away
work persistently
at close quarters
very near or near together
out of fashion
not popular or approved of
explain away
give a satisfactory reason for; remove objection to by means of a convincing argument
at the outset
at the beginning
on the part of
of or by (sb.)
have it (that)
maintain, assert (that)
think over
think carefully about; consider; study
capitalize on
profit by; make full use of (sth.)
in possession of
having; owing
stir up
excite; stimulate; provoke
catch on
become popular or fashionable
Proper Names
Lewis Thomas
刘易斯.托马斯
Darwin
达尔文
Walace
华莱士
Grasse
格拉斯
Lovelock
洛夫洛克
Margulis
马古利斯
Gaia
盖亚