The larger events in the political life of the world are determined by the interaction of material conditions and human passions. The operation of the passions on the material conditions is modified by intelligence. The passions themselves may be modified by alien intelligence guided by alien passions. So far, such modification has been wholly unscientific, but it may in time become as precise as engineering.
The classification of the passions which is most convenient in political theory is somewhat different from that which would be adopted in psychology.
We may begin with desires for the necessaries of life: food, drink, sex, and (in cold climates) clothing and housing. When these are threatened, there is no limit to the activity and violence that men will display.
Planted upon these primitive desires are a number of secondary desires. Love of property, of
