Daniel I thought truth meant the correspondance between reality and an idea, backed by facts and excluded the arbitrary, in other words the mind has to be involved.( relationship between existance and conciousness)Which I guess does mean reason as the only claim to knowledge. If arbitrary guesses were alowed as sourses of truth. How could one ever claim certainty? The point is, one couldn't, and therefore certainty as contextual in the objectivist sense would be replaced by a kind of "absolute certainty" which as a concept would be meaningless because man cannot obtain it(which is how it is used today). People would then(rightly) conclude that certainty is imposible for man and this would open the door for people to claim that"absolute certainty" is possible only by some other means(ie) faith. If you want to be a little more generous toward peikoff, what he is trying to do is rescue the term certainty, by making it possible for someone to claim certainty within a context, while at the same time allowing for the fact that man can be in error. This grounds "certainty" in reality and stops people from using it as an anti-concept. This is what I like about objectivism, concepts refer to reality and are useful in reality. The fact that the rejection of the arbitrary is based on lack of evidence(if existed would be in reality) but this rejection IS overtured when evidence (again in reality) is then persented pretty much shows he is not searching for "true belief". Otherwise he wouldn't specifically say that the arbitrary in one context could become possible in a different context provided new evidence is given. If reason is not the only means to knowledge then THAT is what opens the door for "philosophers throughout the ages" to suggest a different "source of Justified True Belief." (I could accuse you of perhaps wanting that, since you did accuse peikoff of the same, but I wont) I've noticed this lately. Scepticism is actually religions biggest friend, because the scepticism is only amed at man's reasoning ability. The more reason is discredited by scepticism, the more religion as an alternative is hailed as a value because it dosen't follow a method that has a possibility for error. Yet people view scepticism as being against religion. So religion uses scepticism to promote its dogmatism by discrediting its enemy(reason).