December 2, 1921] 



SCIENCE 



551 



Disease is any departure from normal living. . . . 

 The entire iody, organism or creature and the entire 

 race or stock to which it belongs may become ab- 

 normal through subjection to an abnormal or per- 

 turbed mode of life. Such body, creature, race or 

 stock is therefore in a state of disease. 



The question, Wliat is normal living? is 

 answered through a study of the earliest 

 marine faunas. 



Normal living, in the broad sense in which we 

 desire to be understood, means full activity of an 

 unimpaired physiology inclusive of the function of 

 locomotion or mobility. . . . Independent living, 

 freedom of locomotion and range expose the indi- 

 vidual to ever new dangers. These the individual 

 must quickly overcome or outwit; otherwise suc- 

 cumb. The choice is quick, imperious and final. . . . 

 Normal living is, in terms of biology, correct living, 

 that is to say, righteous living, and in so far as 

 dependence invades the mode of life whether in 

 organ or individual, such living is unrighteous, dis- 

 ordered and diseased; in better phrase, biologically, 

 is without hope, for such perturbation or disease is 

 beyond voluntary or casual rectification. 



Out of right or normal independent living 



have come all the great triumphs of life ; the races 

 of life which, by keeping individual and racial inde- 

 pendence, have persistently climbed upward. . . . 

 The giants of the redwood forests are the hoary and 

 venerable obelisks of power shackled beyond re- 

 demption; the gardens of flowers are blossoms of a 

 hope never to be attained. 



In all of the evolution of endlessly variant 

 life, there has been, however, " a strong 

 minimum, a redeeming minority, of compe- 

 tent upward evolution." It is a certainty 

 that the minorities of geologic life have saved 

 the day for us. 



Wise students of nature, in reflecting on this 

 thought, have broken out into exclamations of 

 wonder and amazement at the slender thread of 

 chance by which we who call ourselves men have 

 come to this estate, in a world where for millions 

 of years the temptation to the easier way and the 

 obstacles to independent living were constantly 

 against us. 



It would be trite to say that a perfectly adjusted 

 life is an unprogressive one. The adjusted life 

 makes for conservatism and reduces the chances of 

 variation to its lowest terms. . . . Speaking for the 



moment in higher terms for the individual the 

 adjusted life is likely to carry with it the highest 

 content of happiness. To progress in organic de- 

 velopment it is the undeniable foe, but to the con- 

 servatism of intellectual and spiritual ideals the 

 undoubted friend. 



Clarke finds that 90 per cent, of Cambrian 

 organisms led a life of independence. In 

 subsequent time, dependent life becomes ever 

 greater in individuals and races. Interde- 

 pendent individual life as expressed in mutual 

 and commensal adaptations is sparingly pres- 

 ent in the Ordovician but " not until life had 

 got in full swing did these organic combina- 

 tions come into existence, even in their sim- 

 plest commensal expressions." Out of the 

 innocent combination of symbiosis arises para- 

 sitism, " an adaptation in which one organism 

 has become helplessly dependent on another 

 for its existence." 



If dependence has affected and sealed the fate of 

 one great division of the Kingdom of Life, so that 

 it is and must remain subsidiary to the larger pur- 

 poses of nature, dependence also has entered upon, 

 invaded and degenerated a very large part, indeed, 

 probably the major part of the other, the animal 

 world. . . . Dependent races of animals have sought 

 or accepted dependence as an easier mode of liv- 

 ing, either waiting upon the unconscious forces of 

 Nature, waves and winds, or on the normal activi- 

 ties of other animals. Such dependence has entered 

 in some degree upon all primitive stocks of animal 

 life and from such racial dependence there has been 

 no escape. The lines in the animal world along 

 which links in the chain of advancement have con- 

 tinued unbroken, are but few; the rest have run out 

 into ouls-de-sac where all hope is abandoned. 



Eescue of dependents is therefore not a part of 

 the. scheme of Nature, except through the exercise 

 of intelligence. In Nature's plan of evolution de- 

 pendents of all sorts are negligible and abandoned 

 to hopelessness, save as gradually developing 

 psychic factors intervene. 



These conclusions are so well established that 

 we may rightly look to them for light upon the 

 interpretation of certain tendencies to rest and 

 unrest, conservatism and impulsive change, in 

 human society, and while it may not seem very 

 appropriate to speculate on the further bearing of 

 this theme, it must be said iu looking back over 

 the field of organic history, that the value of the 

 product must be in terms of the worth of the type 



