A long-awaited new edition of Anatoly Protopopov’s widely known work, “A Treatise on Love as a Terrible Bore Understands It,” explains how instincts govern us, what love is from the standpoint of evolution, and why a man and a woman can never truly understand each other. Our attention will focus on love as a phenomenon of choice made by one person for another—and on the possible consequences of such a choice, both for the chooser themselves and for all of humanity. So we can call our approach evolutionary—though not without regard for specific individuals.