Varys said that he does what he does for the good of the realm. Littlefinger said that the realm is a lie, and there is only the individual. Varys says that without a national identity, the people will be thrown into chaos. He compared it to a pit that swallows us all; oblivion that you cannot escape from.
Littlefinger then says that chaos isn\'t a pit, it\'s a ladder. He contradicts Varys by saying that instead of chaos being something you\'re trapped in, it\'s something you use to get out of a pit. It\'s a way to reach heights that you have not reached before. Littlefinger sets up a dichotomy: While others thrive on order and structure, he thrives on Chaos. Chaos is how Littlefinger advances in society.
Now he goes on to explain how people try to climb the ladder (take advantage of opportunities not otherwise open to them) but lack the political astuteness or cunning to do so safely. They \"fall\", which is to say that they die. Here we see Ros, dead. Another example of this might be when Ned Stark tried to briefly seize power from Joffrey because he was not Robert\'s trueborn son, although his motives were far different and he was essentially forced into it.
Then Littlefinger says that others refuse to climb at all, preferring safety and comfort -- the realm, Gods, or love. He dismisses these notions as illusions, and asserts that the climb is all there is while Sansa watches his ship.
Essentially, Littlefinger is supporting a moral doctrine that says everyone ought to be out for themselves. The only purpose in life is to gain power, and all other things - patriotism, love, religious faith - are lies. Only the accumulation of power is \"real\" to Littlefinger. And that power can be accumulated through chaos, by using upheaval to rearrange things so that you are on top.