274 THE RIDDLE OF THE UNIVERSE. 



" the one great thought that controls all the different 

 aspects of animal evolution is the same that gathered 

 the scattered fragments of space into spheres, and 

 linked them into solar systems. This thought is no 

 other than life itself, and the words and syllables in 

 which it finds utterance are the varied forms of living 

 things." 



Baer, however, did not attain to a deeper knowledge 

 of this great genetic truth and a clearer insight into 

 the real efficient causes of organic evolution, because 

 his attention was exclusively given to one half of 

 evolutionary science, the science of the evolution of 

 the individual, embryology, or, in a wider sense, 

 ontogeny. The other half, the science of the evolution 

 of species, phytogeny, was not yet in existence, 

 although Lamarck had already pointed out the way 

 to it in 1809. When it was established by Darwin 

 in 1859 the aged Baer was no longer in a position to 

 appreciate it ; the fruitless struggle which he led 

 against the theory of selection clearly proved that he 

 understood neither its real meaning nor its philo- 

 sophic importance. Teleological and, subsequently, 

 theological speculations had incapacitated the ageing 

 scientist from appreciating this greatest reform of 

 biology. The teleological observations which he 

 published against it in his Species and Studies in 

 his eighty-fourth year are mere repetitions of errors 

 which the teleology of the dualists has opposed to the 

 mechanical or monistic system for more than 2,000 

 years. The " telic idea " which, according to Baer, 

 controls the entire evolution of the animal from the 

 ovum is only another expression for the eternal 

 " idea " of Plato and the entelecheia of his pupil 

 Aristotle. 



