Postulates versus Facts 309 



would roll off the surface. Yet Lamarck attempted seri- 

 ously to avoid unwarranted assumptions and mystic factors. 

 Lamarck was apparently unaware that his fourth law was 

 the crucial one in his whole theory, taking the statement to 

 represent a fact. The discussions in his own lifetime had 

 to do chiefly with two other points — first the general 

 theory that evolution did actually take place, and second, 

 the process by which the individual acquires fitness during 

 his lifetime. As a result, the '* inheritance of acquired char- 

 acters " remained without systematic criticism for nearly 

 two generations. Darwin accepted it without hesitation; 

 Samuel Butler knew it was so. Richard Semon noted the 

 close parallelism between a modification in response to the 

 environment and memory. The organism is impressed by 

 everything that happens to it, and by every response that it 

 makes to outer stimuli. It does actually become stronger 

 and more skillful, tougher or swifter, as a result of its ex- 

 perience. In other words, it learns as a child learns. More 

 exercise, more experience, means more memories or deepened 

 impressions, or better and more reliable habits. From this 

 it is but a short step to recognize in the inborn responses) 

 and ability to adjust — inherited habits. 



Lamarck, as we have seen, distinguished between the 

 adjustments of plants and lower animals, which he con- 

 sidered, so to say, imposed reactions, and the adjustments 

 of higher forms, which he considered manifestations of in- 

 telligence. The former clasps of responses could not be 

 inherited, or at least might not. The latter, however, 

 through effective, purposive effort brought about appro- 

 priate changes in bodily structures and functions. The in- 

 stinctive (that is, unlearned) behavior of subsequent gen- 

 erations are equally effective or purposeful, but do not 

 involve anew the conscious or intelligent striving. Hence, 

 instinct is to be considered as inherited experience — in 

 Lamarck's phrase, the result of lapsed intelligence. With 

 the exercise of instinct, the mechanism improves and each 

 succeeding generation transmits the quality in increasing 



