Watching this on Christmas Eve just before family dinner is the greatest idea I've had in 2019.
Seriously, though, this is "the act of killing with one's own hands". I don't personally recall a statement as outspoken as this one before 1949. Franju presents a slice of hyperrealism in an era of Neorealism and some very scarce remnants of experimental cinema and poetry. This is cinematic dissonance at its fullest expression: Franju employs Jean Painlevés complimentary commentary to address the contrasts between architectonic beauty and urban simplicity with despair, death and gore.
I particularly remember being surprised by the unforgiving, graphic slaughterhouse detail during the opening of Lino Brocka's masterpiece Insiang (1976); now expand that for around 15-16 minutes and add some objectively cold narration with those (sometimes) brief literary references the French couldn't omit when making short and feature-length documentaries. They had their unique catch on things.