shifting understandings of the brain and consciousness over time in being human

“Philosophers have wondered for thousands of years how we can be sure whether what we’re experiencing is reality or some shadowy deception. Plato imagined people looking at shadows cast by a fire in a cave. Descartes imagined a satanic genius. Starting in the 1960s, philosophers began to muse about what it would be like to be a brain in a vat, with reality supplied by a computer. ”