266 EVOLUTION AND PSYCHOLOGY 



emerge above the tide and are impelled by only 

 atmospheric pressure have httle control over. 

 And once more, just as psychiatry is now chang- 

 ing its emphasis from a predominantly somatic 

 and neurological basis, which has been so fruitful 

 under the old slogan of Virchow, " Ubi est mor- 

 bus," to a more psychic, pathological viewpoint, 

 so perhaps even the doctrine of heredity is com- 

 ing our way by changing the terms applied to its 

 elements from the mystic, pathological ids and 

 determinations of Weismann to Semon's no less 

 mystic but psychological postulates of mnemes 

 and engrams. Here, too, we are hardly ready to 

 meet the new demands or utilize the new princi- 

 ples, because our department is still, despite its 

 great, recent progress, only half scientific and is 

 not unlike Milton's new-born tawny lion pawing 

 to get away from the metaphysical and theolog- 

 ical soil from which it sprang. We have too 

 long yielded to the seductions of the heterai of 

 the ancient, speculative problems that have ob- 

 sessed us and not yet definitely broken with those 

 in our midst who still urge that psychology 

 should be developed in the closest rapport with, 

 if not under the influence of, a speculative phi- 

 losophy. 



Finally, as Darwin freed biology from the in- 

 veterate dominance of the ideas of fixed and 

 divinely created species, conceptions directly in- 

 herited from Plato's ideas and Aristotle's cate- 

 gories, so everything in the present psychological 



