Reality, some say, amounts to no more than an illusion they then describe as a delusion. Freud thought of reality as something against which illusions collide. If reality is only an illusion, I think, it is a very useful one humanity is learning to understand. We already perceive why some call it that and are not under an illusion about it. I think of reality not as an illusion, but as a construction. Try that on for size. I think you’ll find it’s more accurate, and far more useful.