1893.] The Quantity of Human Life. 195 
conscious life varies as the number and rarity of its experi- 
ences. But the number and rarity of its experiences depend 
upon a great variety of circumstances. 
They depend upon the diversity of external conditions. 
They also depend upon the extent and acuteness of surfaces 
of contact, and the rapidity with which those surfaces are 
transported into new environments. Finally they will depend 
upon the stock of vitality of the individual. All these factors 
must be considered in estimating the quantity of the conscious 
life. The diversities of external surroundings are very great. 
Even in primitive communities, and amid the habitual isola- 
tions incident to a nomadic life, the differences in the attitudes 
and groupings of the objects of inanimate nature, and of the 
lower orders of animate nature, are ever stimulating the con- 
scious life to new and intense experiences. Surprises, alarms, 
friendship, apathies, pleasures and pain are ever appealing in 
new and varied relations to the would-be slumbering sensibil- 
ities. But when we pass from the primitive condition of 
solitude to the later condition of society where the wide play 
of forces concerned in human interests is brought to bear in 
a multiplicity of combinations upon the individual life, the 
number of conscious experiences increases with the members 
of the community not in an arithmetical, but in a geometri- 
cal ratio. This holds up toa certain point when the maxi- 
mum of conscious experiences during a given time is reached. 
The limit is a subjective and not an objective one. It is 
determined by the capacity for reception of the individual. 
Amid the intricacies of modern civilized life that limit 1s 
speedily reached. Even the most capacious and versatile 
minds soon weary of the endless solicitations of the senses and 
the trains of ratiocination to which they give rise. The keen 
activity of such minds is rapidly dulled by the continuous 
impact of stimuli, and soon falls back upon the restful reitera- 
tion of former experiences. But even the repose of such 
reminiscences is disturbed by the jars and turmoils of inevita- 
ble environments, and the drowsy sensibilities are spurred on 
to renewed activities day after day so long as life continues. 
Thus it happens that the average life of the social individual 
