28 FOOT-NOTES TO EVOLUTION. 
Again, the fact of death has been shown by Weis- 
mann to be a simple necessity of the law of natural se- 
lection. Creatures of one cell are in 
a sense biological units; they may be 
killed but they do not die a natural 
death. They are wholly alive or else wholly dead: never 
dying. They multiply by self-division, and this process 
is supposably eternal, for natural death is known only 
among many-celled or colonial organisms. It is a ne- 
cessity arising from complexity of organization. Com- 
plication and specialization of structure as we know it 
in man and the other many-celled creatures is bought 
at the cost of mortality. These cells grouped in tis- 
sues and organs in one part or another must suffer in 
the struggle for existence. Every compound animal is 
in some part dead or dying. The old and mutilated 
organisms cumber the way of the young and fresh ones, 
and by the law of selection it comes about that for these 
to die of old age is useful to the species. Those spe- 
cies in which old age brings decay and in which the in- 
dividuals perish naturally when they cease to be self-de- 
pendent are then preserved in the struggle for existence. 
It is common in these days to speak of altruism as 
a means of doing away with the struggle for existence 
among’ men. But altruism itself is only 
a higher or more advanced result of the 
same struggle. Those who band to- 
gether win, be they wolves or men, and 
natural selection favours those qualities which make for 
mutual advantage. To band together against enemies 
or for protection from the elements is a most effective 
way in which the struggle for existence may be carried 
on. The law of love is not an abrogation of the law of 
struggle. It represents a better way to fight. The con- 
quests of science are simply the first results of co-opera- 
The value of 
death. 
Altruism and 
the struggle 
for existence. 
