 Another argument calling into question the significance of the observable/unobservable distinction is presented by Ian Hacking (1985, 146–147). Hacking considers a machine which makes grids of the same shape but various sizes. We can see grids with the same overall shape of smaller and smaller size, but the machine makes some grids that are too small to be seen with the unaided eye. When looked at through a microscope, however, the unobservable grids are seen to have the same shape as the observable ones. Hacking writes: