He has devoted his life to utalitarian thinking. Something many logical thinkers do whether done subconciously or not. That is what has allowed him to make the hard decissions, and addopt the cold attitude, you losers seem to find badass. He is an example of some one who has lost hope. I believe this shows that it is possible he did not truly believe in the Will of Fire, his brother, and this world (world of pain). I also think, he helped lead to the downfall of this brother, considering Madara knew how to get out of the Edo Tensei (information which could only have been acquired from the creator).