It's a quote attributed to the French director Jean Cocteau: "I love cats because I enjoy my home; and little by little, they become its visible soul." I haven't found a source citation for that, but I find the attribution plausible, since there are a bunch of photos of him like this:
J'aime les chats, parce que j'aime ma maison et qu'ils en deviennent, peu à peu, l'âme visible. Une sorte de silence actif émane de ces quelques fourrures qui paraissent sourdes aux ordres, aux appels, aux reproches.
This longer version adds 'A sort of active silence emanates from these furry somethings, who seem deaf to orders, to appeals, to reproaches.' Yup, that's cats. :)