Why wouldn't today's "mesmerisms" be just as ridiculous? I don't think the mockery is about "absurd things people back then believed" but about "gullible people

Why wouldn't today's "mesmerisms" be just as ridiculous? I don't think the mockery is about "absurd things people back then believed" but about "gullible people who will believe all sorts of things". I think Conan Doyle was a very gullible man for his time. He would have been gullible for today's quakery if he was still alive.