The _Warlock_ spun around the planet. The members of its crew withdrew into themselves. In even two months of routine tedious voyaging to this planet there had been the beginnings of irritation with the mannerisms of other men. Now there would be years of it. Within two days of its establishment in orbit, the _Warlock_ was manned by men already morbidly resentful of fate, with the psychology of prisoners doomed to close confinement for an indeterminate but ghastly period. On the third day there was a second fist-fight. A bitter one. Fist-fights are not healthy symptoms in a space-ship which cannot hope to make port for a matter of years. * * * * * Most human problems are circular and fall apart when a single trivial part of them is solved. There used to be enmity between races because they were different, and they tended to be different because they were enemies, so there was enmity.... The big problem of interstellar flight was that nothing could travel faster than light, and nothing could travel faster than light because mass increased with speed, and mass increased with speed--obviously!--because ships remained in the same time slot, and ships remained in the same time slot long after a one-second shift was possible because nobody realized that it meant traveling faster than light. And even before there was interstellar travel, there was practically no interplanetary commerce because it took so much fuel to take off and land. It took more fuel to carry the fuel to take off and land, and more still to carry the fuel for that, until somebody used power on the ground for heave-off instead of take-off, and again on the ground for landing. And then interplanetary ships carried cargos. On Xosa II there was an emergency because a sandstorm had buried the almost-completed landing-grid under some megatons of sand, and it couldn't be completed because there was only storage power because it wasn't completed, because there was only storage power because-- It took three weeks for the problem to be seen as the ultimately simple thing it really was. Bordman had called it a circular problem, but he hadn't seen its true circularity. It was actually--like all circular problems--inherently an unstable set of conditions. It began to fall apart simply because he saw that mere refrigeration would break its solidity.