[Raynor]

Is Saruman's turning to evil done unconciously or not?

Saruman followed the path of expediency that tempted Aule, Melkor and Sauron - and, like the later two, he fell and failed to repent

Originally Posted by Notes on motives in the Silmarillion, i, Myths Transformed, HoME X

Sauron had never reached this stage of nihilistic madness [of Melkor]. He did not object to the existence of the world, so long as he could do what he liked with it. He still had the relics of positive purposes, that descended from the good of the nature in which he began: it had been his virtue (and therefore also the cause of his fall, and of his relapse) that he loved order and coordination, and disliked all confusion and wasteful friction. (It was the apparent will and power of Melkor to effect his designs quickly and masterfully that had first attracted Sauron to him.) Sauron had, in fact, been very like Saruman, and so still understood him quickly and could guess what he would be likely to think and do, even without the aid of palantiri or of spies; whereas Gandalf eluded and puzzled him.

On top of that, he was also an incarnate, which emphasisez his weakness

Originally Posted by Letter #181

But since in the view of this tale & mythology Power – when it dominates or seeks to dominate other wills and minds (except by the assent of their reason) – is evil, these 'wizards' were incarnated in the life-forms of Middle-earth, and so suffered the pains both of mind and body. They were also, for the same reason, thus involved in the peril of the incarnate: the possibility of 'fall', of sin, if you will. The chief form this would take with them would be impatience, leading to the desire to force others to their own good ends, and so inevitably at last to mere desire to make their own wills effective by any means. To this evil Saruman succumbed. Gandalf did not.