Which of Alexander the Great's generals would always disagree with him?

Question

I have seem to have forgotton the name of the general that would always disagree with Alexander's battle plans. His disagreements allowed Alexander to see what the enemy would do in the situation therefore allowing him to create a counter attack. He was one of his favorite generals because his other generals would always agree with his battle tactics. This general was briefly mention in an episode of "Military Showcase" on the Military Channel. This episode went over a battle between Alexander the Great and Persia.(If anyone reading this has Tivo it would be especialliy helpfull if you answered this).

Answer 1

That would be Parmenio.

http://en.wikipedia.org/wiki/Parmenio

Enjoy the reading.

Answer 2

There was no one single general who served that function, Alexander did not surround himself with yes men, he deemed sycophants worthless. When he planned a battle he expected every one of his Generals to speak his mind, if the man's opinions and insights weren't worth hearing, he wouldn't have been there.