In just what way can there be a sexual path that is also a spiritual path? In a sense, this is a debate about human ecology, and it is notable that today, as earlier in the twentieth century, those who are "conservatively" critical of over-technologization and the exploitation of nature also tend to be in favor of a more positive attitude toward sex (D.H. Lawrence, J.C. Powys and Eric Gill, for example). Inversely, those who are more conservative, puritanical and legalistic about sex are often those who fully embrace technological modernity, the ruthless exploitation of nature and economic liberalism.
Daniel Mitsui expands on just how positive Eric Gill's sexual attitudes were. Those wishing to preserve what remains of innocence should not read it. Suffice to say, Gill obtained gratification from his dog and frequently violated his own daughters. He matter-of-factly records these events in his diaries. One does not become more exploitative than that.
One is left wondering if Milbank is simply ignorant of Gill's perversions, which were not revealed until 1989. He could even believe the contorted thesis that Gill's artistry is utterly disconnected from his personal debaucheries. An admirer's powers of self-deception are legion.
Another possibility is far worse: he really is so satanic that he approves.