INVENTOR'S JOYS AND SORROWS. 325 



to continue my task, but I have not succeeded there, 

 where everything is pressing forward, in persistently 

 looking backward. For it is habit which puts the 

 strongest snackles on us. I have never been able 

 entirely to put aside the thoughts and plans, which 

 were just then occupying my mind, and this has 

 frequently spoiled my enjoyment of the present, to 

 which I could never wholly devote myself except in 

 passing moments. But on the other hand such a 

 thought-life, partly spent in dreamy speculations, partly 

 in strenuous aspirations, also affords great enjoyment. 

 It sometimes even perhaps brings us the purest and 

 sublimest joys of which man is capable. When a law 

 of nature, hitherto hovering darkly before the mind, 

 all at once clearly emerges from the enveloping mist, 

 when the key to a long vainly sought mechanical 

 combination is found, when the missing link of a chain 

 of thought is happily inserted, this affords the dis- 

 coverer the elevating feeling of an achieved mental 

 victory, which alone richly compensates him for all 

 the pains of the struggle and exalts him for the moment 

 to a higher stage of existence. Certainly the ecstacy 

 does not generally last long. Self-criticism usually soon 

 discovers a dark spot in the discovery, which renders 

 its truth dubious or at least narrowly restricts it. 

 It exposes a fallacy in which one has been entangled 

 or, as is unfortunately almost the rule, it leads to the 

 perception that only an old friend has been met with 

 in a new dress. Only when strict examination has 

 left a sound kernel does the regular hard labour 



cD 



