I've been reading a lot of literature from the late 19th/early 20th century over the past few years. The sheer breadth of ideas that were being casually discussed in magazines that regular, educated people subscribed to is astonishing. Drugs, hypnosis/mesmerism, meditation, trance, new religious movements, weird fasting regimens, transcendental experiences in nature, mysticism. That stuff has disappeared from public discourse today, along with many other radical ideas that could apparently just be talked about over coffee back then, without anyone batting an eyelash.