Apparently co-operation and sharing is what causes society to advance!

“Here is the law of progress, which will explain all diversities, all advances, all halts, and retrogressions. Men tend to progress just as they come closer together, and by co-operation with each other increase the mental power that may be devoted to improvement, but just as conflict is provoked, or association develops inequality of condition and power, this tendency to progression is lessened, checked, and finally reversed.

Given the same innate capacity, and it is evident that social development will go on faster or slower, will stop or turn back, according to the resistance it meets. In a general way these obstacles to improvement may, in relation to the society itself, be classed as external and internal— the first operating with greater force in the earlier stages of civilization, the latter becoming more important in the latter stages.”

Henry George, Progress and Poverty(508-509)

Basically society advances most when we cooperate and share wealth, while war and wealth inequality slow, stop, and regress the progress of society.