7.3 Causes of Change
If the mechanism of meaning changes is now clear, just what it is that put the mechanism into motion seems less clear. However, it is reasonable to assume that whenever new meanings are added to old words, or new words are created, it is in response to some need. For example, when aeroplanes without propellers(螺旋桨) became important suddenly in our daily life, jet quickly expanded to embrace(包含)that concept. There are generally two major factors that cause changes in meaning.
1. Extra-linguistic Factors(非语言因素)
As time elapses(推移), changes keep taking place in society and our daily life and new concepts, ideas and new things emerge continuously. Man has come to know about the world around him all the more. All this will certainly be reflected in language. This accounts partly for the semantic change.
1) Historical Reason
The well-known semanticist Ullmann notes, 'language is more conservative than civilization, material as well as moral. Objects, institutions, ideas, scientific concepts change in the course of time; yet in many cases the name is retained and thus helps to ensure a sense of tradition and continuity(延续性). Indeed, it often happens that a word is retained for a name though the meaning has changed because the referent has changed. Take pen for example. Originally, it denoted 'feather', which was used in the West as pen in old times, hence the present meaning. Now, the time when 'feather' served as pen is long gone, and people are using ball-point pens and fountain pens, yet the name is still kept. Car which used to be a 'two-wheel cart drawn by horses and used in war' has taken on the meaning 'automobile' with the development of modern car industry. This change has also occurred to computer, which formerly designated a 'person who computes'. At present, when we talk about computer, people would think of an 'electronic machine' rather than a person.
Increased scientific knowledge and discovery is also an important factor that underlies the change of word meaning. For instance, before Copernicus(哥白尼), the sun was thought to be 'the luminous(会发光的) celestial body(天体) that in the Plolemaic system is one of the seven planets revolving around the earth and this meaning is retained in 'The sun rises and sets'. The Copernician theory tried to change the historical point of view and now everyone knows that the sun is a 'star around which the earth and other planets revolve. . . ' (WTNID). The concept of atom too has changed with the increase of scientific knowledge. The word is derived from the Greek form atomos, which meant 'any of the indivisible particles(微粒)'. Now science has proved that atom is not the smallest and can be divided into even smaller particles, hence the abandonment of the original meaning.
2) Class Reason
Language is just like a mirror, reflecting everything that exists in human society. Naturally, it records the speech and attitude of different social classes. As a result, different social varieties of language have come into being. The so-called 'King' s English' serves as good illustration. The attitudes of classes have also made inroads into lexical meaning, particularly in the case of elevation or degradation. For instance, quite a number of words that denote different sorts of working people or their occupations have deteriorated(降格) and now have taken on a pejorative sense, for in the eyes of the nobility, working people were badly brought up and were 'ignorant and foolish' , and 'rude' and 'coarse'(粗鲁) in behaviour. Churl, hussy, wench, villain as we already know were originally neutral in color but have all been down-graded as ' ill-mannered or bad people'. Democracy, revolution, liberalism, human rights, communism have certainly different meanings in different societies and to different people.
3) Psychological Reason
The associated transfer of meaning and euphemistic use of words, etc. are often due to psychological factors. Take copperhead (铜头蝮蛇) for example. This word designates 'a venomous snake' in North America and was later employed to refer to those: northerners during the American Civil War who were secretly aiding and abetting(教唆,煽动;支持,帮助) the South. It is said that people in the North had a deep hatred and contempt(蔑视) for such people. The editor of one country newspaper was trying to find a suitable word. First, he thought of 'rattlesnake' as it was the most poisonous reptile(爬行动物) but rejected the word because it at least announces its presence by the rattle(响尾蛇) in its tail, unlike those informers(告密者). Consequently, copperhead was chosen and endowed with a new meaning (Bernard and Delbridge 1980:195).
People change word meaning owing to various psychological motives: love, respect, courtesy, suspicion, pessimism, sarcasm(讥讽), irony(讽刺), contempt(鄙视), hatred, etc.. The meanings of slang are in general far from their standard meanings because on the spur of the moment(一时冲动之下) , a word suddenly occurred to the speaker's mind to serve the purpose of expression. For example, in the Second World War, prevalent in the Australian forces were peasant(老粗) for 'soldier of ordinary rank', squeak (帮手)for 'sergeant'(下士), comedian(喜剧演员) for 'commando'(突击队员) (pejorative), stewkeeper(炖汤员) for 'cook'(厨子). In prison, it is particularly common to use old words for new meanings: boob-head (笨蛋)for 'one who returns too often to jail'(屡次入狱的人), sucker, cock sucker for a 'toady'(献媚者), shelf, chocolate, frog, dog for an 'informer', arse(饭桶) for 'despised prisoner'(受鄙视的囚犯), square-head(良民) for an 'honest man' and suchlike.
The fact that such low, humble and despised occupations as janitor(看门人) and garbage collector often take on more appealing names is all due to psychological reasons. Besides, religious influence is another kind of psychological need. As Archbishop Trench once said, angel(信使→天使), martyr(殉教者→烈士) and paradise(伊甸园→天堂) have their meanings elevated because of the influence of Christianity (Robertson and Cassidy, 1957).
2. Linguistic Factors
The change of meaning may be caused by internal factors within the language system. One type of such change occurs when a phrase is shortened to one word which retains the meaning of the whole,e. g. gold is used for 'gold medal', gas for 'coal gas', and bulb for 'light bulb', and private for ' private soldier'. Under such circumstances, whatever is left, whether a noun or an adjective, is all used as a noun assuming the original meaning.
Secondly, the influx of borrowings has caused some words to change in meaning. For instance, deer formerly meant 'animal', and later animal from Latin and beast from French found their way into English. As the three terms were synonymous, animal retained the original meaning, the meaning of deer was narrowed and beast changed in color. In Old English, animals and their meat shared the same name. With the Norman Conquest and borrowing of corresponding French words, the English words were kept only for live animals and the French words for the animals when they have been killed and brought to the table, e. g. pig—pork , sheep-1-mutton , cattle—beef. In addition, the competition of native words eventually yielded the semantic division. For example, bird—fowl, dog—hound, boy—knave, chair—stool were synonyms early in history. Now the former of each pair keeps the original meaning and the latter became specialized.
Finally, the change of meaning is brought about by analogy. Fortuitous formerly denoted ' happening by chance', 'accidental', and later took on the meaning 'fortunate' probably by analogy because the two words look similar in shape. It is the same with fruition , the original meaning being 'a pleasure obtained from using or possessing something' , which had nothing to do with fruit. Its meaning of 'the bearing of fruit' was due to the later association with the word fruit .

