THE THEORY OF DESCENT. 75 



twofold or dualistic, often the teleological or vital, because 

 it traces the organic natural phenomena to final causes, 

 acting and tuorJcing for a definite purpose (causse finales). 

 It is this deep and intrinsic connection of the difierent 

 theories of creation with the most important questions of 

 philosophy that incites us to their closer examination. 



The fundamental idea, which must necessarily lie at the 

 bottom of all natural theories of development, is that of a 

 gradual development of all (even the most perfect) or- 

 ganisms out of a single, or out of a very few, quite simple, 

 and quite imperfect original beings, which came into exist- 

 ence, not by supernatural creation, but by spontaneous 

 generation, or archigony, out of inorganic matter. In 

 reality, there are two distinct conceptions united in this 

 fundamental idea, but which have, nevertheless, a deep in- 

 trinsic connection — namely, first, the idea of spontaneous 

 generation (or archigony) of the original primary beings ; 

 and secondly, the idea of the progressive development of 

 the various species of organisms from those most simple 

 primary beings. These two important mechanical concep- 

 tions are the inseparable fundamental ideas of every theory 

 of development, if scientifically carried out. As it maintains 

 the derivation of the different species of animals and plants 

 from the simplest, common primary species, we may term 

 it also the Doctrine of Filiation, or Theory of Descent; as 

 there is also a change of species connected with it, it may 

 also be termed the Transmutation Theory. 



While the supernatural histories of creation must have 

 originated thousands of years ago, in that very remote 

 primitive age when man, first developing out of the monkey- 

 state, began for the first time to think more closely about 



