This has been a lot hotter issue in the past than it is now, but it’s an important one. Bossuet discussed it in his History of the Variations of the Protestant Churches; my comment on the subject is as follows:
Especially interesting are the Vaudois, who were in reality an unauthorised, non-celibate religious community in Catholicism more than a stand-alone church; their main fault is that they believed that unworthy priests did not administer valid sacraments. (Anyone who has been in church work knows that gauging the worthiness of ministers can be a dicey proposition at best; I think the Vaudois were unreasonable in that regard.)
This is not to say that we should not be vigilant in weeding out ministers of bad character; it means that they are able to administer sacraments and do other good things, shall we say, in spite of themselves. On that point, getting rid of the sacraments doesn’t really solve the problem, especially when we consider those who have evangelised in the past and then fallen. They have a lot to answer for, but at least someone involved is going to heaven…
Positive Infinity 