Born in Scotland and raised in Germany, Mackay was the author of Die Anarchisten (The Anarchists, 1891) and Der Freiheitsucher (The Searcher for Freedom, 1921).

[2] During a one-year stay in London (1887/88), he discovered the works of Max Stirner, whose book Der Einzige und sein Eigenthum (The Ego and its Own) had nearly been forgotten in the second half of the 19th century.

When an English translation of Stirner's work was published in 1907, James Huneker wrote: "To Mackay's labors we owe all we know of a man who was as absolutely swallowed up by the years as if he had never existed.

"[3] The publication of the novel Die Anarchisten: Kulturgemälde aus dem Ende des XIX Jahrhunderts in Zurich in 1891 and in an English translation as The Anarchists: A Picture of Civilization at the Close of the Nineteenth Century the same year brought him far wider fame.

[5] After his mother's death, he embarked on a literary project under the pseudonym Sagitta, to argue on behalf on homosexual relations between men and boys.

It failed to achieve the earlier volume's success and Mackay was ruined financially by the inflation of the early Weimar years.

[8][a] Providing a blurb for the 1985 English translation, Christopher Isherwood wrote that the novel "gives a picture of the Berlin sexual underworld early in this century which I know, from my own experience, to be authentic.

His counterpart Hermann, six or seven years older, "tedious and ineffectual" in one critic's view,[10] arrives to take a job in a publishing house and is destroyed by his infatuation with Gunther.

[16] Mackay lived in Berlin from 1896 onwards and became a friend of Benedict Friedlaender, a scientist and the co-founder of the Gemeinschaft der Eigenen.

[17] Richard Strauss set two of Mackay's poems to music in his Vier Lieder for high voice and piano (Op.

[19] "Puppenjunge" can also be translated as "Puppetboy", which suggests the main character is a puppet at the whim of his circumstances, which may have been Mackay's intent.