Sábato is a former physicist and one of Argentina's foremost intellectuals who has been preoccupied with the complexities of the "human condition" in many essays and articles. After incorporating this "condition" in El túnel, this work was labelled by the critics as a psychological detective story, a tale of crime and passion, an expressionistic document, a reflection of French existentialism and, above all, a testimony of man's inability to reach a spiritual understanding with the human beings around him.

El túnel deserves all of these attributes because the author was skillful enough to create a structure that allowed him to build in these themes. The plot centers around the tragic existence of the painter Juan Pablo Castel, a man who had lost faith in humanity after he had stopped believing in himself…. Only after meeting María Iribarne, the one person who seemed to grasp the meaning of his artistic self-expression, does life resume a function of purposiveness…. When Castel realizes that even María will forever remain an incomprehensible entity, separate from his own, he kills her, thus expressing his despair over the futile attempts to share her existence. Having severed his ties to society, Castel is oblivious to the physical confinement in a prison cell, aware only of being condemned to exist in his private tunnel.

Sábato's portrayal of Castel's transcendental search not only represents a participation in a fundamental quest for the tragic condition of modern man, exemplified today by writers like Max Frisch or Saul Bellow; it also constitutes, ironically, a proof that Argentina has become a modern mass society in which deshumanización and alienación are key words…. Sábato's "case history" really is a forerunner of a Kulturkrise as well as a diagnosis of the social ills that afflict the present Argentine society. Castel's psychasthenia may not be shared by the reader but his tunnel is frightfully real.