When Obi-Wan says "Only a Sith deals in absolutes." is that an absolute in itself?

Or is there some way to Justify him saying that. I am being told by someone that he is contradicting himself but I mean don't you have to acknowledge parts of the dark side? Also, I think it's safe to say Obi-Wan didn't mean this about EVERYTHING just in the case of "you're either with us or against us" that sort of absolute. so because I am sure that's what he meant would that disqualify that statement as being an absolute on the terms of what he actually meant it by?