Assess the valence intensity of the sentence "It was also in the 1800s when the debate itself over the cause of homosexuality was started by Magnus Hirschfeld, a physician, sex researcher, leading sexologist, homosexual, and founder of the first gay rights movement in Germany, who believed that homosexuality was biological in nature (Marcus 10)." based on the mood of the author. Offer a numerical rating between 0 and 1, with 1 representing highly positive and 0 representing highly negative.