55 LAMARCK, AIS LIFE AND WORK 
““ However, were it not for the picture that so 
many celebrated men have drawn of the weakness 
and lack of human reason; were it not that, inde- 
pendently of all the freaks into which the passions 
of man almost constantly allure him, the zgnorance 
which makes him the opinionated slave of custom 
and the continual dupe of those who wish to deceive 
him; were it not that his reason has led him into 
the most revolting errors, since we actually see him 
so debase himself as to worship animals, even the 
meanest, of addressing to them his prayers, and of 
imploring their aid; were it not, I say, for these 
considerations, should we feel authorized to raise 
any doubts as to the excellence of this special light 
which is the attribute of man? 
‘* An observation which has for a long time struck 
me is that, having remarked that the habitual use 
and exercise of an organ proportionally develops 
its size and functions, as the lack of employment 
weakens in the same proportion its power, and even 
more or less completely atrophies it, I am apprised 
that of all the organs of man’s body which is the 
most strongly submitted to this influence, that is to 
say, in which the effects of exercise and of habitual 
use are the most considerable, is it not the organ of 
thought—in a word, is it not the brain of man? 
‘“Compare the extraordinary difference existing 
in the degree of intelligence of a man who rarely ex- 
ercises his powers of thought, who has always been 
accustomed to see but a small number of things, 
only those related to his ordinary wants and to his 
limited desires; who at no time thinks about these 
same objects, because he is obliged to occupy him- 
self incessantly with providing for these same wants; 
finally, who has few ideas, because his attention, 
continually fixed on the same things, makes him 
notice nothing, that he makes no comparisons, that 
he is in the very heart of nature without knowing it, 
