Just as Barack Obama's primary victories remind us that change often goes hand in hand with progress, so the sudden news of Kennedy's illness is a somber reminder that change also is inevitably loss. Call it tragic wisdom.
When he first took his seat in 1962, Jim Crow and its de facto shadow were a fact of American life, and women's rights barely extended beyond the franchise.
A new world, surely, and one he helped usher in. But also one that seems to be unfolding without three qualities that distinguished Kennedy's long service.
The first is empathy. It's shocking just how tenuous belief in the possibility of empathy as a public emotion has become. Kennedy's brother, Bobby, was fond of quoting the ancient Greeks. One of them, Thucydides, once was asked, "When will there be justice in Athens?" He replied, "There will be justice in Athens when those who are not injured are as outraged as those who are."