CHAPTER 2 . HOW CAN WE KNOW 



THE DIFFERENT KINDS OF LIVING THINGS? 



1 How many different kinds of animals are there in the world? 



2 What is meant by saying that the dog is related to the wolf, 



or that the lion is related to the tiger? 



3 In what sense is one species related to a different one? 



4 Can the animals of different species breed together? 



5 How can we tell a weed from a useful plant? 



6 Why do we class some animals higher and others lower? 



7 What do we need to know about a plant or animal before we 



can tell in what class to place it? 



8 What is the easiest way of finding the name of a new or 



strange plant or animal? 



9 Why are Latin names used for plants and animals instead of 



common names? 

 10 Who needs to know all the scientific names? 



The world is so full of a number of things that we should be very much 

 confused if we could not put them — and keep them — in some kind of order. 

 About the first question we ask regarding a new and strange object is "What 

 is that?" As we grow older, we want to know more than the name. For 

 the new and strange thing is in some ways like whole groups or classes of 

 objects we have known before, although it differs from them in some ways 

 too. In time we learn to say, that is a kjnd of deer or sheep, that is a t{ind 

 of daisy: each novelty is one of a class which we already know. 



The grouping or sorting of objects is necessary for making order out of 

 our world. The naming of objects is necessary for keeping order. The better 

 we sort and the clearer we name, th-e better we can manage the great heap 

 which would otherwise be chaos. 



How Is Sorting Started? 



Naming before Sorting We name common things so that we may 

 communicate about them with one another. And naming is probably an 

 important part of thinking about things. At first the child becomes 

 acquainted with separate objects — this plate, mother, that bottle. He usually 

 receives a separate name for each particular person. Later he calls many 

 separate, but similar, objects by the same name: all chairs, all cats, all trees, 

 all persons. 



We use one name for many distinct objects because they appear enough 

 alike to let us take one for another. And for many practical purposes one 



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