What does this theme mean:
"Blind Pursuit of an Ideal is Destructive"

Interesting that the quote is not found on the net.

I'd think that terrorists are perfect examples of blind pursuit of an ideal being destructive.

This theme relates to Gatsby creating himself in the pursuit of Daisy. His whole existence is to win Daisy; a symbol of this is his looking longingly at the green light across the water. The water itself is a symbol of the distance between Gatsby and Daisy that can never be overcome. When Daisy rejects Gatsby at the end he remains true to his dream, waiting outside until she goes to bed after killing Myrtle, and then the fact that he dies because he has taken the blame for the accident that Daisy caused. It is also interesting that during the novel, when Gatsby and Daisy get together Gatsby is overcome by darkness, the lights at his mansion go out and he stops having parties. The destructive nature stuff relates to the fact that Gatsby’s whole life ends up being so senseless, he created himself and his wealth for Daisy and then is completely rejected and destroyed because of it. You could also talk about the fact that no one seemed to care enough when he died to come to his funeral. Hope this helps (it may be a little incoherent!)

Another interpretation of that theme would be that the end justifies the means. Who cares what you did to get what you want just as long as you get what you want.

I disagree, in this novel no one gets what they want, so the end didn't justify the means. I think in fact the opposite was shown, the theme of the novel shows that it isn't worth it as you may end up dead in a swimming pool dying for the woman you love who doesn't even come to your funeral.