No solo este ensayo se convierte en imprescindible por ser el primer texto largo y enjundioso que publicara Roberto Arlt, sino porque su tematica y las cuestiones, cuando no, pulsiones animicas, que desvela y denuncia el gran novelista bonaerense siguen, a pesar de los noventa anos transcurridos desde su publicacion, en el tapete de nuestro dia a dia. Mas aun cuando esta edicion, profusamente notada, permite, frente a todas las anteriores, una mejor comprension de la inmensa enganifa y confusion que late bajo eso que se entiende como esoterismo y espiritualidad, y que un joven Arlt, con una perspicacia fuera de lo comun, capto de un golpe en estas breves, cuanto agudas, paginas. Por todo ello, Las ciencias ocultas en la ciudad de Buenos Aires es un manifiesto de una actualidad indudable para cualquier buen lector en lengua espanola.

Roberto Arlt, celebrated in Argentina for his tragicomic, punch-in-the-jaw writing during the 1920s and 1930s, was a forerunner of Latin American "boom" and "postboom" novelists such as Gabriel Garcia Marquez and Isabel Allende. "Mad Toy," acclaimed by many as Arlt's best novel, is set against the chaotic background of Buenos Aires in the early twentieth century. Set in the badlands of adolescence, where acts of theft and betrayal become metaphors for creativity, "Mad Toy" is equal parts pulp fiction, realism, detective story, expressionist drama, and creative memoir.
An immigrant son of a German father and an Italian mother, Arlt as a youth was a school dropout, poor and often hungry. In "Mad Toy, " he incorporates his personal experience into the lives of his characters. Published in 1926 as "El juguete rabioso," the novel follows the adventures of Silvio Astier, a poverty-stricken and frustrated youth who is drawn to gangs and a life of petty crime. As Silvio struggles to bridge the gap between exuberant imagination and the sordid reality around him, he becomes fascinated with weapons, explosives, vandalism, and thievery, despite a desperate desire to rise above his origins. Flavored with a dash of romance, a hint of allegory, and a healthy dose of irony, the novel's language varies from the cultured idiom of the narrator to the dialects and street slang of the novel's many colorful characters.
"Mad Toy "has appeared in numerous Spanish editions and has been adapted for the stage and for film. It is the second of Arlt's novels to be translated into English.

Arlt es una de las voces mas personales de la prosa hispanoamericana de comienzos del siglo XX. La carga de angustia y violencia de sus escritos impregna un soporte liguistico aspero, dislocado, vivisimo. A las lecturas de novelas picarescas se alio su experiencia directa del mundo del hampa.