From "The invasion of the body snatchers" to "The Thing": infection, possession and dehumanization

As superbly pointed out by Thomas Ligotti, Don Siegel's "Invasion of the Body Snatchers" (but even more the Philip Kaufman remake) and John Carpenter's "The Thing" bring to the big screen one of the most disturbing ghosts of our time, which we could define the triple "spectrum of dehumanization": dehumanization of the human species due to the invasive action of an alien agent; dehumanization of the human community towards one's fellow men; dehumanization of the human individual in its most intimate aspect.