A guy named Robert Campbell has critiqued Peikoff's views on the 'arbitrary'. http://hubcap.clemson.edu/~campber/peikovianarbitrary.pdf I suppose this technically isn't Oism, because he introduced us to this after Rand's death, though that didn't stop him from putting it in OPAR. Hm... I think Campbell's case makes sense. Whadda y'all think?