The downfall of civilized states tends to come not from the direct assaults of foes, but from internal decay combined with the consequences of exhaustion in war.

A modern state is such a complex and interdependent fabric that it offers a target highly sensitive to a sudden and overwhelming blow from the air.

A complacent satisfaction with present knowledge is the chief bar to the pursuit of knowledge.

I used to think that the causes of war were predominantly economic. I came to think that they were more psychological. I am now coming to think that they are decisively "personal," arising from the defects and ambitions of those who have the power to influence the currents of nations.

In reality, it si more fruitful to wound than to kill. While the dead man lies still, counting only one man less, the wounded man is a progressive drain upon his side.

For the spread and endurance of an idea the originator is dependent on the self-development of the receivers and transmitters.

The search for the truth for truth's sake is the mark of the historian.