Not at all: Yoda deals with absolutes too. 'Do, or do not. There is no try.' (Ep V). Yoda ain't no Sith.

Anakin has presented Obi Wan with a logical fallacy, the false dilema. 'Either you're with me, or you're my enemy' (or words to that effect). Obi Wan tries to say that he could be not with him, but not be his enemy by saying 'Only a Sith deals in absolutes'. Obi Wan wasn't really considering what he was saying, although he has been under a lot of pressure lately so I'll forgive him.

The line does suggest a certain hostility to fundamentalsit religion (including the Sith?) in favour of relativism, which is interesting in today's political climate.

I think what Obi Wan should have said is 'Only a Sith deals in absolutes like that'. Clearly he shouldn't be distrustful of all absolutes, as the statement itself is an obsolute!

May the force be with you all

Heinrich