Warning! Major Spoilers Ahead.
His morals are very black and white and he won’t settle for anything that he thinks is wrong. The bad guys want money from Jeffrey Lebowski and The Dude goes to do the tradeoff but Walter won’t let it happen, he has to give them a ringer, he doesn’t care that this has nothing to do with him; he has to do what is right. He doesn’t want an urn for his friend’s ashes because he plans to scatter them so when the funeral home forces him to buy one he gets very angry and ends up putting his friend in a big coffee can. And then of course when he Donny, and The Dude are getting mugged he refuses to give anything “What’s mine is mine”, and then proceeds to humiliate the muggers by kicking their asses. Sure if he had just let the muggers take their pocket money they would have come out on top because no matter how much money they had it still wouldn’t be enough to make up for the loss of Donny’s life, but for Walter it is more possible for him to flap his arms and fly than it is to give what is rightfully his.
He is also the type of guy that will express his annoyance in detail. When a normal person gets annoyed they might just ask the person annoying them to stop or do something similar. If Walter gets annoyed with you he either snaps at you angrily and tells you to “Shut the fuck up”, he bites off your ear, he smashes your car with a crowbar, and even points a loaded gun to your face if you want to mark your bowling score higher than what he thinks it should be, which ties into his morals again “This isn’t Nam, there are rules”.
While his black and white approach to right or wrong makes him a very strong willed character, he does have an inflated opinion about himself. He thinks he is smarter than he really is and thinks he can get stuff done when he really can’t. He insists that he can perform his deluded plan perfectly and get the money and make everyone happy; he can’t. He also insists that he “…can get you a toe by 3 o’clock with nail polish”, and although we never find out if he actually can, I bet the house that he can’t. The situations surrounding himself and The Dude are way out of their league and The Dude knows it but Walter thinks that he can outsmart everyone and bend good guys and bad guys to his will.
Behavior like his in the film had me convinced for the first two times I watched the film that Walter was a comedic character but upon my third viewing something strange happened to me. I realized that I was totally wrong; he is most definitely a very funny character to watch but he is the most dramatic character of all, he is the most disturbed, and he is certainly the most important character in the film for without him I don’t believe there would be a film, but more on that later.
Take for example films like “Gran Torino” and “Taxi Driver”. Both films have a main character that is a war veteran and shows his scars in their respective movies. Travis Bickle and Walt Kowalski both are funny in a bitter kinda way, they both take the law into their own hands, they have black and white morals, and they won’t stand quiet when there is injustice going on. Why should Walter Sobchak be thought of as any different? He is in a comedy film yes, but as far as his character goes there is not much difference. “Taxi Driver” and “Gran Torino” both deal with war veterans helping children from trouble they have gotten themselves into and I am certain that if Walter was put in that situation he would react the same way.
Earlier I said that without Walter there wouldn’t be a film. This is because all the events that push the plot forward are propelled by him. The Dude wouldn’t have done anything about his rug if Walter hadn’t convinced him to do something. It was Walter’s idea to throw a ringer to the kidnappers, even if the ringer was replacing another ringer. Walter was the one who found the little kid who stole the car, and it was Walter who beat up the nihilists in the parking lot causing Donny to have a heart attack. The Dude has not motivation and couldn’t move the plot of the film by himself; he is a lazy, unemployed stoner, with no drive to do anything except go bowling.
When you see how dramatic Walter really is it almost makes you sad, because you realize that all the funny things he does in the movie are actually stuff that in the real world would be considered psychotic episodes worthy of locking him up in an institution and the saddest part is that people like him could be your next door neighbor or anyone you know that has seen war first hand.