Gilfillan, an engineering consultant to industry and government and self-described as a frequent participant in nuclear war games, dabbles in the future of humanity the way most of us used to dabble in mudpies, and with as few socio-ethical scruples. Human life, after all, presents the same advantages to the tough-minded as mud to the four-year-old: it's ""the only resource we have which is free, and the only one we have which we can squander without ever running short of it."" Gilfillan is pretty sanguine about most global problems taken individually (pollution and radiation aren't that bad; starvation and psychological adaptation will stabilize overpopulation and defuse the crisis), but thinks that in combination, they're an excellent argument for departing to other solar systems as soon as we work out the technology. Stage One will be huge manned space stations--eventually millions of them--in our own system, each supporting a more or less permanent weightless population of a thousand on an atmosphere of pure oxygen and producing nearly all of its own necessities by fractional distillation (from granite) in the vacuum of space. Then come voyages to the nearer stars--as many voyages as possible, since most of them won't survive (hence a need for a huge population to provide the interstellar equivalent of cannon fodder. Get the title now?). Eventually the colonies will recapitulate the whole process: the colonists will leave overcrowded planets until man has leapfrogged through the entire Milky Way. (This grandiose scenario is embellished by such minor tidbits as a plan for controlling the surface temperature of the moon by reflecting mirrors and giant shades and the speculation that the Chinese were originally a race of space castaways.) In the end we shall accept the necessary cruelty of our evolutionary destiny (i.e., to colonize) and abandon hypocritical scruples about any humanistic values that happen to fall by the wayside. Irresponsible intergalactic triage.