memberships (churches, clubs, political parties, socioeconomic groups, etc.) is to BREAK its rules mindfully. THis means the person does so knowing full well what the repercussions and backlash for his/her actions or words might be. While the word heresy is rooted in lots of religious history, a mindful heretic is possible not just in religious organizations, but also in broader secular contexts as well.
A theologian who chooses to write what s/he believes to be true despite the religious consequences is also a mindful heretic. See Matthew Fox’s Confessions of a Post-Denominational Priest for a great example.