520 POPULAR SCIENCE MONTHLY. 



ing the inconsistent and premature metaphysical conceptions which 

 stealthily creep into all branches of knowledge. The natural scientist 

 frequently rails against metaphysics in the very words of metaphysics, 

 without knowing that his entire mental activity is based on metaphys- 

 ical preconditions. Metaphysics is the old man of the sea whom the 

 scientific Sindbad carries on his own shoulders, without, however, feel- 

 ing the load. 



After having studied the limits and validity of human knowledge, 

 the philosopher is ready for the construction of his metaphysical sys- 

 tem. He calls to his aid the history of philosophy, which unrolls before 

 him the thoughts of past ages and bids him profit by their experience. 

 The history of philosophy must not be regarded as ' a disconnected 

 succession of arbitrary individual opinions and clever guesses,' it is 

 not a formless aggregate of errors, not a series of unsuccessful at- 

 tempts to reach truth. It is not a Sisyphean labor, a Penelopean woof. 

 The history of philosophy is a development, an evolution, in which the 

 forms which follow generally show an advance over what precedes. 

 And even if it were a mere catalogue of errors, it would be of service 

 to the metaphysician by pointing out to him the lines of thought that 

 have ended in blind alleys; it would warn him against wasting his 

 energies in fields that have been worked over. The man who knows 

 how a solution can not be effected is on the road to knowledge. 



