barked Colonel the sheepdog

My comments yesterday at doctorwho when it was suggested that Doctor Five was so dark that it would have been interesting if Ainley had been cast as the Doctor and Davison cast as the Master.

My initial reaction to the idea that the Doctor's fifth personality was "dark", though, was: Not in itself, really, but in the way it was never quite properly formed, except for those few minutes in the Zero Room at the beginning. Peter and JNT wanted and needed Doctor Five to be markedly dissimilar from Doctor Four, so they brought in the Master to traumatize him physically, mentally and emotionally in the immediate wake of the regeneration, creating a personality much less assured and much less competent than the Doctor would naturally regenerate into. Some of the comments the Doctor made in Episode 1 of The Twin Dilemma were seen by the contemporary fan press as slags against Davison, but I thought they were thoroughly in character and (allowing for Doctor Six's acerbic manner) factually accurate. I trace to this outright instability the darkest thing Doctor Five did, the attempt to murder Davros in cold blood (though I maintain there were other factors involved as well). But note that such an action is so out-of-character for even the most maladjusted Doctor that he was dissauded by the most transparent promises of reform from someone of whom he ought to have known better. I don't think the Doctor's fifth personality ever quite recovered and healed from the Event One/Castrovalva plot against it, and I think it was less "dark" than confused and adrift.

It was replied that the Doctor's murder attempt on Davros is tied for Doctor Five's darkest action with the deaths of Kamelion the shapeshifter robot and the Master, both in Planet of Fire:

Naaah... Taking out Kamelion was a mercy killing at Kamelion's request. Taking out the Master was a mercy killing on behalf of the rest of the universe, and was a sin of omission rather than commission at a chance opportunity; the Doctor might even have changed his mind had he had more time to think about it.

But the Davros incident was an out-and-out decision and conspiracy to commit cold blooded murder. Dark dark dark.