204 evolution: the ages and tomorrow 



present level of civilization is problematic. There are many- 

 pessimists, including Ortega y Gasset, who see in this situa- 

 tion the greatest dangers for the future of our civilization. 

 Science, Ortega points out, succeeded in establishing itself 

 completely only in modern times and only in Europe and 

 America. Seers, priests, and warriors we have had with us 

 always, but the experimental scientist is a product only 

 of our age. To have experimental scientists calls for a rather 

 unique and exceptional combination of circumstances, not 

 the least of which are the highest levels of intelligence and 

 freedom from want and the pressures of demagogues and 

 dogma. 



Here again is an obstacle in the path of evolutionary 

 progress. Science in increasing degree and quality is abso- 

 lutely necessary to ultimate understanding. The way up- 

 ward does not lead through theology, nor even through 

 philosophy, for the philosopher must depend on science for 

 the basic tightness of his insight. There is no revelation, nor 

 does the brain secrete thought as philosophers once beheved. 



The differences in the innate capacity to learn, which 

 have so great a bearing on our future, are hereditary. A large 

 genetic component, a pattern of genes which is inherited 

 from both parents, controls the complex organ and neuro- 

 logical structure that establishes the potential for intelligence 

 in the individual. Whether that potential is fully realized or 

 not, particularly if it is of a high level, depends on environ- 

 mental factors such as accidents to the body structure, dis- 

 ease, malnutrition, lack of education, unfavorable eco- 

 nomic and social surroundings, and so forth. Environment 

 can veto but not determine intelligence. Low-level intellect 

 cannot be made up for by high-level environment. High- 

 level intellect can, on the other hand, be prevented by an 

 adverse environment from reaching the potential set by the 

 genes. 



Einstein needed the optimum in family surroundings, 

 educational opportunities, and cultural friendships, which it 



