While dooku did seem evil and suduced by the dark side he also was fighting to overthro the republic he said because the senate was corrupt by the master of the sith. isnt that kinda a good thing?
Well, considering that the master of the sith controlling the senate was also his master, I think it should be fairly obvious that it was all just a part of Palpatines plans. He wasn't rebelling against the senate due to corruption, he was acting like he was in order to draw out other systems, making the republic weak allowing Palpatine to get control easier.
Dooku lost his faith in the Jedi Order. I don't know if he thought they were Evil, like Anakin came to believe, but he certainly thought they were Wrong. Dooku joined the Sith because he felt jaded by the Jedi and because Dark Side can seem rather glamorous and seductive, but never because of an outright desire to be eeeevil. However, like many Sith Lords, Dooku's thirst for power (and fear of losing that power) became too great for his own good.
Dooku is not evil. Sidious' power lies in the mind not the body. He led Dooku to believe in how corrupt the Republic was (which was true) but led him to the Dark Side to make him think he could clean it up.
I agree with The_Negotiator...I believe that Dooku did not join the dark side to become EEEEEVIL per se. He joined the dark side in order to gain POWER. Palpatine promised him an easy victory, and so he took it. Dooku was blinded by power. That was his weakness... To summarize it, Dooku was not evil (er, before he allied with Sidious). What he did, before he took orders from Sidious, he did, to overthrow the republic he believed was CORRUPT. He was a Separatist --- not a villain. More of an anti-hero really. But the more he fell to the dark side, the more he was corrupted by the darkness of the Sith.
Dooku was not evil... He was a Jedi Master who brought peace and prosperity to the Republic. Though when he became Darth Tyranus, the Sith Lord was evil. So yes I agree with the sentiment that he started out with good intentions but the influence of the dark side and his embraceing of the Sith corrupted him. Count Dooku is awesome... just because he is old doesen't mean he is a dcrepid old crazy with old man smell. Hell if you had old man smell wouldn't you turn to the dark side ? j/k Count Dooku ( Darth Tyranus as I like to call him ) is one of my fav villians... The Sith rock !
But the quest for power. The willingness to take any path to get there. the fact that he wanted to take the easy path, which is not the way of the Jedi, show how Dooku became evil. In dark renedzous(sp?) Dooku wonders if he was always tainted by the darkside.
Dooku is evil but he might not have realized it. He never saw his efforts come to their evil fruition. He was a guy scorned by the Jedi Counsel and was vulnerable to corruption. Sidious corrupted and convinced he was doing the right thing. So, perhaps Dooku was merely a victum of the Sith. Also, I don't know if you can be so definitive when saying the Jedi=good and the Sith=evil. Watching ROTS made the line between Sith and Jedi blurry.
Dooku was conflicted. In EP2 I believe his intentions were to change the philosophy of teh Jedi order, similar to Qui-gon's attitude. He wanted the Jedi to adapt to the times, and when he realized that they wouldn't he decided to take things into his own hands. But before doing all of that, he first wanted to rid teh galaxy of the Sith by joining them. He thought that he could destroy the dark side from within...he was wrong. By Ep3 I believe that he had forgot about his ideals and became a true slave to the dark side.