Born at "Kikerud", Valbo in Ryrs parish. When still a baby his parents moved to Kaserna in Foss parish, Bohuslan. Wikner became senior lecturer in philosophy at the University of Uppsala from 1864 and was appointed professor of philosophy and aesthetics in Christiania (Oslo) in 1884.

He married in 1871. He lived in many respects according to the slogan "all or nothing" and his "love for Jesus" often came into conflict with his "love for a friend". In situation where infatuation threatened to overturn ideals, he often chose to break off the relationship and flee into an exalted worship of Jesus.

Wikner's contribution to homosexual history consists foremostly of producing the first description of the problematics about homosexual identity and the coming-out process. He deposited for future research at the medical faculty in Uppsala his Psychological Self-Confessions from 1879 and diaries from 1853 to 1871. According to his own wishes, they were not published before his wife and sons - the nearest members of the family - had died.

Against the argument that homosexuality is unnatural, he answered that only that which according to the laws of nature cannot occur is unnatural. And nothing is bad which does not injure or harm any person. He pleaded to all future readers to give homosexuals the right to get married.