Scientists must accept facts even when they would like them to be different. They must strive to distinguish between what they see and what they wish to see —— for humanity's capacity for self-deception is vast. People have traditionally tended to adopt general rules， beliefs， creeds， theories， and ideas without thoroughly questioning their validity and to retain them long after they have been shown to be meaningless， false， or at least questionable. The most widespread assumptions are the least questioned. Most often， when an idea is adopted， particular attention is given to cases that seem to support it， while cases that seem to refute it are distorted， belittled， or ignored. We feel deeply that it is a sign of weakness to "change out minds." Competent scientists， however， must be expert at changing their minds. This is because science seeks not to defend our beliefs but to improve them. Better theories are made by those who are not hung up on prevailing ones.
Away from their profession， scientists are inherently no more honest or ethical than other people. But in their profession they work in an arena that puts a high premium on honesty. The cardinal rule in science is that all claims must be testable —— they must be capable， at least in principle， of being proved wrong. For example， if someone claims that a certain procedure has a certain result， it must in principle be possible to perform a procedure that will either confirm or contradict the claim. If confirmed， then the claim is regarded as useful and a stepping-stone to further knowledge. None of us has the time or energy or resources to test every claim， so most of the time we must take somebody's word. However， we must have some criterion for deciding whether one person's word is as good as another's and whether one claim is as good as another. The criterion， again， is that the claim must be testable. To reduce the likelihood of error， scientists accept the word only of those whose ideas， theories， and findings are testable —— if not in practice then at least in principle. Speculations that cannot be tested are regarded as "unscientific." This has the long-run effect of compelling honesty - findings widely publicized among fellow scientists are generally subjected to further testing. Sooner or later， mistake （and lies） are bound to be found out； wishful thinking is bound to be exposed. The honesty so important to the progress of science thus becomes a matter of self-interest to scientists.
NEW WORDS
represent vt. be a sign or symbol of； act for 代表
collective a. of or shared by a group of people 集体的
insight n. the power of using one's mind to see or understand the true nature of a situation 洞察力
wisdom n. intelligence and good judgment 智慧
reoccur vi. occur again
dependability n. reliability， trustworthiness
prediction n. the act of predicting or sth. predicted 预测 headway n. motion forward； progress
answerable n. able to be answered replace vt. take or fill the place of
superstition n. a belief or practice based on ignorance， faith in magic or chance
