The Things They Carried is so beautifully written. The story On the Rainy River, about a young man struggling with whether to avoid the draft, had this which has stuck with me:

If the stakes ever became high enough - if the evil were ever evil enough, if the good were good enough - I would simply tap a secret reservoir of courage that had been accumulating inside me over the years. Courage, I seemed to think, comes to us in finite quantities, like an inheritance, and by being frugal and stashing it away and letting it earn interest, we steadily increase our moral capital in preparation for that day when the account must be drawn down. It was a comfortable theory. It dispensed with all those bothersome little acts of daily courage; it offered hope to the repetitive coward; it justified the past while amortizing the future.