Since his first extraordinary work, “Migraine,” was published in 1970, the neurologist Oliver Sacks has been writing a particular kind of medical literature. Siri Hustvedt has long explored the intersections and interplay of science and storytelling. Of the many specious arguments against gun control, perhaps the most ridiculous is that what we really need is the opposite: more guns, in the hands of more people, in more places. As the nation’s leaders devise new gun control strategies following the Connecticut shooting, they should look for ways to strengthen state laws that govern the possession and use of firearms. Maybe this time will be different.