16 , WHY WE FORGET. 



than any other, the value and necessity of obser- 

 vation, not only for making us ready and success- 

 ful in action, but for making us ready and profound 

 in thought. It is, therefore, worthy of a little 

 consideration ; and it is the more so that it is not 

 much, if at all, noticed in the common books, 

 which profess to school us in the most useful of 

 all arts the art of making the best use of our 

 faculties. 



Why do we lose the memory of our thoughts in 

 sleep ? The common answer is, " Because we are 

 asleep;" but though in most instances that satis- 

 fies us, it does not satisfy the question. It is an 

 identical proposition, the two parts of which have 

 the same meaning, though the words are dif- 

 ferent ; and such propositions give us no know- 

 ledge, though they deceive us with the appearance 

 of it. If the question were, " How does a man 

 get on his journey by walking?" and the answer 

 were, "Just because he walks, "that would be just as 

 much (that is, as little) to the purpose as the former. 



But when we consider that we lose the memory 

 of our thoughts when we are awake, not only oc- 

 casionally, but (perhaps in all men) more frequently 

 than we retain it ; and that we can pass through 

 the day-dream of reverie into a state of as utter 

 forgetfulness, both of sensation and of thought, 

 while we are to appearance wide awake and walking 

 on our feet, as when we are in the most profound 

 and unbroken sleep ; we cannot believe that sleep 

 is the cause of forgetfulness. Sleep-walking is so 

 very like profound reverie during a day- walk, that 

 one can hardly tell the one from the other. Indeed 

 the reverie may be the more " oblivious" state of the 

 two ; because in it the motions of the limbs are 



