DEATH AND RESURRECTION. 55 



of the extremely complicated mode of 

 propagation characteristic of insects, 

 doubts as to generatio spontanea increas- 

 ingly arose. It was, however, at a com- 

 paratively late time, or in the middle 

 of the seventeenth century, that Harvey 

 formulated his famous thesis, ^^omne 

 virum ex oro,''^ or, as it has been later 

 said, "onme vivum ex vivo," which we 

 may translate thus: '^Life implies life; 

 all living beings descend from previous 

 existing parents,''^ or negatively, "A^o liv- 

 ing being is generated from lifeless matter.''^ 

 Thus, for the first time, the idea was 

 pronounced by natural science that life 

 is a specific force; an independent prin- 

 ciple, that has not its roots in the ma- 

 terial world. 



As generatio aequivoca leads to ma- 

 terialism, so Harvey's formula leads to 

 pure idealism. That these consequences 

 should have been seen from the begin- 

 ning, was so much the less to be ex- 

 pected since even today no such dis- 

 covery has been made or could have 

 been made, simply because no atten- 



