266 BIOLOGICAL LECTURES. 



nothing can shake. The movement of the stream of phenomena 

 takes a subordinate position in consciousness, and the mental 

 activities attach themselves by preference to stable, island-like 

 forms and principles. 



Thinkers from the earliest times to the present day seem .to 

 be referable to one or the other of these two classes. The dif- 

 ferentiation begins in early Greek philosophy with men like 

 Heraclitus and Parmenides. To Heraclitus the world was an 

 unceasing flux — Travra pec, ovSev fievet, all things are Jiowing, 

 ?io thing is standing still. All things are forever becoming, noth- 

 ing ever is. Parmenides, who fixed the trend of the Eleatic 

 school, belonged to the other class. He is the philosopher of 

 rest. The chaotic, multiform world of Heraclitus, forever in 

 motion, becomes for him merely a world of nonexistent appear- 

 ances, a shifting phantasmagoria, and only being is — the abso- 

 lute — the one, forever at rest. 



The contrast in these two views reappears between Aristotle 

 and Plato. This difference is seen in the all-pervading move- 

 ment as conceived by Aristotle in his Physics, in contrast 

 with the " ideas " of Plato. Movement to Aristotle is " some- 

 thing very analogous to our modern biological conception of 

 transformation in development, for he analyzes ' movement ' 

 as every change, as every realization of what is possible." ^ 

 Plato, on the other hand, under the influence of Parmenides 

 and the philosophy of rest, emphasizes the forms and qualities 

 that keep recurring to our minds in time and space, generaliz- 

 ing them into his " ideas " and endowing them with all the 

 attributes of reality.^ He would say, e.g., of a living animal as 

 it stands before us : " This animal as we see it does not exist in 

 reality, but is only an apparition, a continual becoming, a rela- 

 tive existence, which can as well be called nonexistent as 

 existent. The idea alone actually exists which is represented 

 in this animal, or the animal itself {avro to Oripiov). This idea 

 is independent of everything ; it exists by itself ; it has not 

 become; it does not decay, but exists always in the same 



1 Osborn, H. F. From the Greeks to Darwin. New York, Macmillan & Co., 

 1894. p. 50. 



2 See Pater, Walter. Plato and Platonism, Chaps. I, II. 



