60 Recent Literature. [ZOE 
during the past two centuries, although the mean level may have 
risen. He seems to look upon human progress as advancing along 
one direct line, and from this point of view it might indeed seem 
that the high-water mark had not advanced. There is, however, 
another aspect of the subject. It is customary to represent the 
progress of life by the analogy of a tree; why not, then, look upon 
human progress as taking place in the same manner? According 
to this view the civilizations of Egypt, of India and of Greece repre- 
sent the terminal buds of their respective shoots. Modern civiliza- 
' tion started afresh from the trunk of the tree, and may indeed not 
yet have grown much above the tips of the old growth of Egypt or 
Greece; yet there can be no doubt that the new growth is a larger 
limb and has infinitely greater prospects of future progress. 
Mr. Wallace then proceeds to consider the factors which have 
been operative in the past and those which may be expected to ex- 
ert an influence on the future advance or deterioration of mankind. 
He shows how the warfare of tribe with tribe has destroyed the 
weaker, while the greater vital energy of higher races frequently 
causes the extinction of the lower. Still more powerful than this 
warfare of one tribe with another is the survival of the fittest among 
the individuals of a single tribe. ‘‘On the whole,”’ says the writer, 
‘‘we cannot doubt that the prudent, the sober, the healthy and the 
virtuous live longer lives than the reckless, the drunkards, the un- 
healthy and the vicious; and also that the former, on the average, 
leave more descendants than the latter.”’ He asserts that this pro- 
cess ot elimination will raise the mean level, but very properly adds 
that “it can have little or no tendency to develop higher types in 
each successive age; and this agrees with the undoubted fact that 
the great men who appeared at the dawn of history and at the cul- 
minating epochs of the various ancient civilizations were not, on the 
whole, inferior to those of our own age.’’ (p. 149.) This is, how- 
ever, a very remarkable passage for Mr. Wallace to pen, for he has 
here virtually given up his customary Neo-Darwinian stand. If the 
process of natural selection or elimination cannot develop higher 
types of man by the selection and accumulation of already existing 
variations, how indeed can natural selection produce higher types of 
animals, as Mr. Wallace claims, by the selection of fortuitous varia- 
tions? But he forsakes this position in another place. How, in- 
deed, can the passage just quoted be made to harmonize with the 
