Doug Cummings has pointed me to a 9 minute NFB film that he figures should be listed among the Top 100 spiritual films, commenting that "It made a big impression on Lucas, Kubrick, and others. (And me!)." It's a 1964 film by Arthur Lipsett.
The film is new to me, so I'm just starting to mull it over. Clearly it's asking questions about the uniqueness of humankind, juxtaposing images of human movement with machine movement and animal movement, human bodies relating to machines and animals, overlaid with text and sound that invokes transcendence. Fascinating.
You can view it online at the NFB website.