Who wrote the book of love? In an impassioned polemic, Ron Rosenbaum - who has written books on the mysteries of thermonuclear explosions - takes on perhaps his greatest challenge: the nature of love. Rosenbaum argues that what we know as love is imperilled now by the quantifiers, the digitizers, and their algorithms, who all seek to reduce love to electrical, chemical, and mathematical formulas. Rosenbaum brings excitement to his thinking as he interrogates the neuroscience of love, with its 'trait constellations,' and the efforts of others to turn all human lovers into numerical configurations. He asks us why our culture has become so obsessed with codifying and quantifying love through algorithms. The very capacity that makes us human, Rosenbaum argues, is being taken over by numerical methods of explanation. In Defense of Love is more than an examination of the intersection of love with literature and science. It is a celebration of the persistence of a mysterious and uncanny phenomenon: the inexorable power of love.