“The heart has got to open in a fundamental way,” Leonard Cohen sang in his timeless ode to democracy — an insight not blunted by romantic mysticism but, like every Cohen lyric, honed by the complex reality of life and the most elemental truths of the human experience. Dr. Martin Luther King, Jr. knew this when, in laying the groundwork for nonviolent resistance, he asserted: “Along the way of life, someone must have sense enough and morality enough to cut off the chain of hate. This can only be done by projecting the ethic of love to the center of our lives.” Half a century earlier, Tolstoy had articulated the same notion in his correspondence with Gandhi, one of Dr. King’s great influences: “Love is the only way to rescue humanity from all ills.”