I was doing a chapter in the 7th grade Faith and Life Religious Ed books with my students and there was a part about "errors concerning the Incarnation". It covered Arianism and Docetism and the part about Docetism, which I'd never heard about before, sounded a lot like what I knew about Manichaenism. I told the kids, since we're from St. Augustine's Parish, that St. Augustine believed all that stuff before his conversion. But I'm not sure if that was right.
Concerning who Jesus was, it seems that both heresies taught the same thing. That He was only God and not really a man. And both are reduced to the same fundamental body=bad soul=good problem. So, what is the difference between the two? Are Docetists always Christian and the followers of Mani pantheists?