Explanations 407 



tion? Everybody wants satisfactory answers to the question 

 " Why? " And most attempts to answer a question begin- 

 ning with Why, start with Because, Generally speaking, 

 we have come to think of cause-and-effect relationships 

 in two different ways, what we may call the mechanical 

 and the mental. And there are two corresponding types of 

 explanation. 



The mental type of explanation is illustrated in our 

 interpretation of human conduct in all sorts of everyday 

 situations. We say, for example, I stopped because I heard 

 the whistle; or, The child cried because he hurt his finger. 

 We attempt to answer the question " Why? " by reference 

 to a purpose, or a reason, or a desire. We interpret the actions 

 of buyers and sellers, of lovers and criminals, of candidates 

 and voters, of beggars and princes, by assigning motives, 

 such as we can understand because we experience them 

 ourselves. People act as they do because they have in mind 

 a desired end, and action is explained by a supposed state 

 of mind. 



Whether or not our interpretation of motives is sound 

 or adequate, it is but a short step to transfer it to other liv- 

 ing things. And then we catch ourselves saying. The birds 

 are going south to avoid the cold winter; or, The caterpillar 

 crawls on the under side of the leaf because he is afraid to 

 be seen; or. The root of the plant grows downward through 

 the soil in order to reach the water — or downward through 

 the water in order to reach the soil. In hundreds of situations 

 we can observe in a plant or animal an activity having an 

 obvious relationship to the needs of the organism, or of the 

 species. And at once we " explain " the action by reference 

 to the possible or probable use. 



Most of us go a step farther and transfer this type of 

 interpretation to all kinds of events. We assume useful ends 

 as sufficient to explain everything. It rains because our crops 

 need the water. Night alternates with day because we can 

 sleep better in the dark. The rosebush has thorns because 

 the flowers need protection from rude boys. 



