No belief or all belief.
For a psychologist he's hitting the extremes. I'd like to see the entire lecture to see if he's trying to bring his students to a middle ground.
Well yeah he does.
But defining the extremes is the point.
In the context of TBL I contend that there is a strand that positions the Nihilists at one extreme and Walter at another with the Dude in the middle.
Another strand is the "manhood" question. Donny at one end being totally emasculated (shut the fuck up Donnie) and Walter defining a cartoonish machoism. Again with the Dude in the middle. He ties the room together.
So the Dude is all things (and nothing). He is a nihilist (hence the Sartre book we see on his shelf Being and Nothingness) but not totally a nihilist.
He is after all one of the authors of the port Huron Statement. He believes in things and more importantly believes in believing in things. But not so much.
He'll show up but he's fine with just sparking some Thai Stick.
He's equally ambivalent about the topic of manhood. He contends that his manhood is essentially a pair of testicles. Johnson?
Which he is in Jeopardy of losing to the nihilists. The Dude defines the middle path and is beset from both extremes.