TETRAPLASY, THE LAW OF THE FOUR INSEPARABLE FACTORS 



OF EVOLUTION. 



By Henry Fairfield Osborn, LL.D., Sc.D. 



Causation or Causality (Lat. causa, derived perhaps from the root cav- as in caveo, and meaning 

 something taken care of; corresponding to Gr. air la) f a philosophical term for the operation of causes 

 and for the mental conception of cause as operative throughout the universe. The word " cause' 1 

 is correlative to " effect." Thus when one thing B is regarded as taking place in consequence of the 

 action of another thing A, then A is said to be the cause of B f and B the effect of A. . . . The senses 

 can say only that in all observed cases B has followed A, and this does not establish necessary con- 

 nection. . . . J. S. Mill argues that, scientifically, the cause of anything is the total assemblage of 

 the conditions that precede its appearance, and that we have no right to give the name of cause to one 

 of them exclusively of the others. ... (3) Efficient cause {tyxh *#• am^ec*), the alcohol which 

 makes a man drunk, the pistol-bullet which kills. This is the cause as generally understood in modern 

 usage. . . . Vera causa is a term used by Newton in his Principia, where he says, "No more causes 

 of natural tilings are to be admitted than such as are both true and sufficient to explain the phenomena 

 of those things"; verce causae must be such as we have good inductive grounds to believe do exist in 

 nature, and do perform a part in phenomena analogous to those we would render an account of. (11th 

 Edition Encyclopaedia Britannica, pp. 557-558.) 



Cause and effect are not two but one. That they are inseparable is indeed recognized by the 

 relativity of the very terms themselves ... in content they are absolutely identical. It is only in 

 form that they can be distinguished, and then we may speak of the one as determining, and of the 

 other as determined. (Welton, Manual of Logic, vol. II, p. 25.) 





CONTENTS 



Introduction 



Page 

 278 



How the Problem is Approached 278 



Reasons for the Historical Method of Analysis 280 



Special Action of Each of the Factors 284 



1. Environment 284 



2. Ontogeny 285 



3. Heredity, including Variation 291 



4. Selection 294 



Coincident Selection 295 



Interaction of the Four Factors 296 



1. Initiation and Genesis 300 



2. Initiation in Environment 301 



3. Initiation in Ontogeny 302 



4. Initiation and Genesis in Heredity 304 



5. Genesis as observed in Palaeontology 304 



Summary 306 



Appendix by William K. Gregory 307 



Previous Papers by the Author Developing this Subject 307 



277 



