238 FROM A NEW ENGLAND HILLSIDE. 



know. I find &quot; I don t know&quot; the house 

 hold words most familiar in my mouth. 

 &quot; As our little lite is rounded with a sleep,&quot; 

 so our little knowledge is rounded with an 

 illimitable ocean of nescience. Moreover, 

 it is well to remember that much of that 

 which we call knowledge, much of that 

 which is classed as &quot;science&quot; to-day, is 

 here and there founded upon hypotheses, 

 admirable for a working basis, but subject 

 to modification, or rejection, as investiga 

 tion progresses. For many people it is very 

 difficult to remember this, and they are 

 apt to talk and act as if there were con 

 ditions of positiveness about that which 

 is oftentimes merely tentative. So long 

 as a theory will explain all the known 

 facts, it is a good theory ; the moment a 

 discovery is made of something for which 

 it does not account, it falls to pieces like 

 a house of cards. And our knowledge, so 

 far as we have it, is relative : this, that, and 

 the other, stand in a certain proportion and 

 connection with each other ; beyond is the 

 infinite gulf, we are suspended in mid 

 air. For the ancients, the world rested 

 upon the back of an elephant, and the ele 

 phant stood upon a tortoise : the tortoise 

 upon what ? 



