It has become rightly fashionable to ridicule the idea of “safe spaces,” places where adults can hide and sulk like children avoiding ideas they find threatening. But women need actual safe spaces—not from intellectual challenge, of course, but from physical threat of harm from men. As a biological matter, most women are physically outmatched by men. Men are stronger and faster than we are, though we’re better able to tolerate pain and tend to live longer.

House Democrats introduced a bill this month that would outlaw safe...