On Knowing the Difference
It is as though we can know nothing of a thing until we know its name．Can we be said to know what a pigeon is unless we know that it is a pigeon？we may have seen it again and again，and noted it as a bird with a full bosom and swift wings．But if we are not able to name t except vaguely as a "bird"，we seem to be separated from it by a vast distance of ignorance．Learn that it is a pigeon however，and immediately it rushes towards us across the distance，like something seen through a telescope．No doubt to the pigeon fancier（愛好者）this would seem but the most basic knowledge，and he would not think much of our acquaintance with pigeons if we could not tell a carrier from a pouter．That is the charm（魅力）of knowledge-it is merely a door into another sort of ignorance．
   There are always new differences to be discovered，new names to be learned，new individualities to be known，new classifications to be made．No man with a grain of either poetry or the scientific spirit in him has any right to be bored with the world，though he lived for a thousand years．
   There is scarcely a subject that does not contain sufficient differences to keep an explorer happy for a lifetime．It is said that thirteen thousand species of butterflies have already been discovered，and it is suggested that there may be nearly twice as many that have so far escaped the naturalists．Many men give all the pleasant hours of their lives to learning how to know the difference between one kind of moth（哦）and another．One used to see these moth-hunters on windless nights chasing their quarry fantastically with nets in the light of lamps．In chasing moths，they chase knowledge．This，they feel，is life at its most exciting，its most intense．
   The townsman passing a field of sheep finds it difficult to believe that the shepherd can distinguish between one and another of them with as much certainty as if they were his children．And do not most of us think of foreigners as beings who are all turned out as if on a pattern，like sheep？
   Thus our first generalizations spring from ignorance rather than from knowledge．They are true，as long as we know that they are not entirely true．As soon as we begin to accept them as absolute truths，they become lies．I do not wish to deny the importance of generalizations．It is not possible to think or even to act without them．The generalization that is founded on a knowledge of and a delight in the variety of things is the end of all science and poetry．

Title：On Knowing the Difference
Passage outline	Supporting details
The（1） importance/significance importance/significance of a name in knowing a thing	●Not knowing its name，you will feel distantly（2） separated separated from a thing however many times you've seen it． ●A thing will become magically close and（3） clear clear to you the moment you are able to name it． ●The charm of knowledge（4） lies/consists lies/consists in that its boundaries can be always pushed back．
A world full of differences	●As there's always something new remaining to be（5） explored/ discovered explored/ discovered ，one is not supposed to suffer any boredom with the world in his lifetime． ●One subject alone contains so many（6） differences differences that anyone interested may have to devote his（7） life/lifetime life/lifetime to learning them． ●By chasing knowledge，people will experience the greatest（8） excitement excitement and intensity that life can offer．
True but never entirely true generalizations	●The way the townsman look at sheep and we look at foreigners illustrates that our first generalizations are made out of（9） lack lack of knowledge． ●Important as generalizations are in our thinking and acting，they will become lies once we regard them as absolute（10） truth（s） truth（s） ． ●Coming to know the variety of things with delight is the final generalization all science and poetry aim to make．