In Graham Greene's The Quiet American we find the following quote, as said by Fowler about his partner, Pyle:
All the time that his innocence had angered me, some judge within myself had summed up in his favour, had compared his idealism, his half-baked ideas founded on the works of York Harding, with my cynicism. Oh, I was right about the facts, but wasn’t he right too to be young and mistaken, and wasn’t he perhaps a better man for a girl to spend her life with?
In the story, Fowler and Pyle are two soldiers during the Vietnam war whose perspectives are different in almost every aspect. Fowler is an angry, cynic man who does not care much about the politics of war nor the nature of human behavior. He is aloof to anything that could remotely render him "sentimental", and his angst against what is happening is reflected in his carelessness and his treatment of others. On the other hand, Pyle is a seemingly good man who aims to please and genuinely believes in the capability of others to do good.
The excerpt quoted above is a manifestation of Fowler's mentality towards innocence. To him, innocence is a really dangerous thing that occurs either by accident, or by way of feebleness. Fowler is so hardened by his own life that he cannot appreciate the kindness that others show in their way of thinking. However, Fowler's anger is not entirely based on stubbornness. Instead, he thinks that innocent people, or naive people, never see both sides of everything they believe in. He is more concerned about the negatives of the war rather than its possibly positive outcomes. Fowler thinks of the now. It is for this reason that he cannot agree with anyone who is an idealistic dreamer, or who lives off philosophical views of life.