The problem with our sensory world – this “blooming, buzzing confusion” of sights, sounds and smells – is that we put so much faith in it. We believe that the world we experience the world as it is, and that our sensations are an accurate summary of reality.

But that’s a convenient illusion. In fact, it is the one illusion that makes every other perceptual illusion possible. Although we’re convinced that we’re living in an Ingres canvas – full of exquisite detail and verisimilitude – we actually inhabit a post-impressionist painting, rife with empty spaces and abstraction. It’s a world so full of ambiguities that it requires constant interpretation.