In short, they do not have access to the same shared reality we do. They do not have embodied experiences, and cannot sense the world as we can sense it; they don't have vision, sound, taste, or touch. They cannot feel emotion or tightly hold a coherent set of values. They are not part of cultures, communities, or histories.

Kurzweil opts for a more organic metaphor. “I am rather like the pattern that water makes in a stream as it rushes past the rocks in its path,” he writes in The Age of Spiritual Machines. “The actual molecules of water change every millisecond, but the pattern persists for hours or even years.”