To do so because you are worried about the purity of your soul
I don't see it as that. IMO he was worried about the very real harm he might do to other people and society in a position of power. Dumbledore doesn't strike me as someone who is needlessly neurotic over anything; if he had fears in this regard, those fears will have had some justification. If it had been only a duty, taken on unwillingly... But for all we know, part of him still wanted the position quite badly; maybe that was which gave him warning. And personally I'd rather not see a charismatic, brilliant man who wrote the letter that Rita Skeeter quoted in a place of too much political power. And even in the older Dumbledore there's often a precarious balance between goodness and kindness and a harder, not-quite manipulative streak. He does have the tendency to use people quite ruthlessly for the cause.
And his reason for delaying the confrontation with Grindelwald was a different one - the very personal fear of finding out that he himself might have killed his sister. Dumbledore himself calls this shameful. But the implication of his own account is that even without being minister, he could have confronted (and defeated) him earlier, so these are two separate issues.
no subject
I don't see it as that. IMO he was worried about the very real harm he might do to other people and society in a position of power. Dumbledore doesn't strike me as someone who is needlessly neurotic over anything; if he had fears in this regard, those fears will have had some justification. If it had been only a duty, taken on unwillingly... But for all we know, part of him still wanted the position quite badly; maybe that was which gave him warning. And personally I'd rather not see a charismatic, brilliant man who wrote the letter that Rita Skeeter quoted in a place of too much political power. And even in the older Dumbledore there's often a precarious balance between goodness and kindness and a harder, not-quite manipulative streak. He does have the tendency to use people quite ruthlessly for the cause.
And his reason for delaying the confrontation with Grindelwald was a different one - the very personal fear of finding out that he himself might have killed his sister. Dumbledore himself calls this shameful. But the implication of his own account is that even without being minister, he could have confronted (and defeated) him earlier, so these are two separate issues.