Question: Who portrayed Venus in a 1845 opera about struggle between sacred and profane love, and redemption through love?

The sacred–profane dichotomy is an idea posited by French sociologist Émile Durkheim, who considered it to be the central characteristic of religion: "religion is a unified system of beliefs and practices relative to "sacred things", that is to say, things set apart and forbidden."  In Durkheim's theory, the sacred represented the interests of the group, especially unity, which were embodied in sacred group symbols, or "totems".  The profane, on the other hand, involved mundane individual concerns.  Durkheim explicitly stated that the sacred–profane dichotomy was not equivalent to good/evil.  The sacred could be good or evil, and the profane could be either as well. <SEP>  The story centers on the struggle between sacred and profane love, and redemption through love, a theme running through much of Wagner's mature work. Tannhäuser (] ; full title Tannhäuser und der Sängerkrieg auf Wartburg, "Tannhäuser and the Minnesingers' Contest at the Wartburg") is an 1845 opera in three acts, music and text by Richard Wagner, based on two German legends; Tannhäuser, the legendary medieval German Minnesänger and poet, and the tale of the Wartburg Song Contest. <SEP> Sacred and Profane Love (Italian: "Amor Sacro e Amor Profano" ) is an oil painting by Titian, probably painted in 1514, early in his career.  The painting is presumed to have been commissioned by Niccolò Aurelio, a secretary to the Venetian Council of Ten, whose coat of arms appears on the sarcophagus or fountain, to celebrate his marriage to a young widow, Laura Bagarotto.  It perhaps depicts a figure representing the bride dressed in white, sitting beside Cupid and accompanied by the goddess Venus. <SEP>  Her voice, "a paradoxical voice—larger than life yet intensely human, brilliant yet warm, lyric yet dramatic"—"was the kind you recognize after one bar, and never forget," wrote Cori Ellison in "Opera News".  Troyanos' performances "covered the full range of operatic history" ("New York Times") in an international career of three decades which also produced a variety of memorable operatic recordings, among them "Carmen" (co-starring Plácido Domingo and conducted by Georg Solti), cited by "Classicalite" almost four decades later as "the finest of all "Carmen"s." After ten years based at the Hamburg State Opera, Troyanos became widely known for her work with the Metropolitan Opera beginning in 1976, with over 270 performances (several dozen of them broadcast or televised) spanning twenty-two major roles.  "She was extraordinarily intense, beautiful, and stylish in roles as diverse as Eboli, Santuzza, Geschwitz, Venus, Kundry, Jocasta, Carmen, and Giulietta, in addition to her great 'trouser' roles," said the Met's longtime Music Director, James Levine. Tatiana Troyanos (September 12, 1938 – August 21, 1993) was an American mezzo-soprano of Greek and German descent, remembered as "one of the defining singers of her generation" ("Boston Globe").  The Met's live telecasts of her "signature" trouser roles, Octavian in "Der Rosenkavalier" and the Composer in "Ariadne auf Naxos", have been preserved on DVD, along with her portrayals of Eboli (in "Don Carlo"), Santuzza (in "Cavalleria rusticana"), Venus (in "Tannhäuser"), and Didon (in "Les Troyens").