Jack Spicer (1925-65) was an American poet. He was closely associated with the San Francisco Renaissance of the mid to late 1950s and friends with the poets Robin Blaser and Robert Duncan.

A key component to his thought on writing centered on the notion that the poet is a medium, who dictates what comes to him from "the Outside":

Now, the difference between "We have come to bring metaphors for your poetry" and what I think most poets who I consider good poets today believe -- and this would include people as opposite in their own ways as say, Eliot on on hand and Duncan on the other -- is essentially that there is an Outside to the poet. Now what the Outside is like is described differently by different poets. And some ot ther blieve that there's a welling up of the subconcious of of the racial memory or the this or the that, and they try to put it inside the poet. Others take it from the Outside. (Gizzi 5)
While Spicer was at Berkeley as a student, he took classes with the German medievalist Ernst Kantorowicz and later enrolled for a PhD in Anglo-Saxon and Old Norse -- he completed the course work but not the thesis. (Ellingham and Killian 19-20 & 41). These academic influences may have had an effect in producing The Holy Grail.