After life in the biosphere, or world of living things, comes the dybosphere, or the world of living but artificially created things in which machines can perform human functions (including, as the author gently puts it, creating other machines) and humans grow more machine-like. Landers lists an impressive lot of current achievements--heart machines, stomach magnets--to show the increasing rapprochement between medical men and engineers. He then goes on to demonstrate that, just as doctors are learning from the mechanics, so, too, the engineers, in their quest to perfect their inventions, are making their machines more and more human. The end of this line lies somewhere between the two spheres, Landers suggests, with men as easily repairable as machines and machines with all the best human qualities. The weakest chapters are those in which he attempts to outline the economic, social, and personal problems of a world run by near-perfect thinking machines. But Landers is only human-after his extensive review of progress in the field of ""dybology,"" a word his thoughtful text will undoubtedly back up as permanent, he leaves us with hope: machine-psychologists are now called in to counsel neurotic computers. Good luck to all of us, men and machines alike!