In 1959, he published the essay Eclissi dell'intellettuale, an unconventional work in which, starting from a critique of mass society based on the analysis of Adorno and Horkheimer, also took a stand against political and cultural lobbies and progressive conformism.

In 1968, after a trip to the Southwestern United States, he wrote a history of the image of the Indian in American literature, I letterati e lo sciamano [The Scholar and The Shaman].

In later years he devoted himself to travel in India, Indonesia, China, Korea, and especially in Iran, which gave ample information in the book Aure.

It featured writings by intellectuals such as AJ Heschel, Jean Servier, Henry Corbin, Cristina Campo, Quirino Principe, Guido Ceronetti, Peter Citati, Sergio Quinzio, Margarete Riemschneider, Jorge Luis Borges, Hossein Nasr, Leo Schaya, Eugenio Montale, Giuseppe Dale, and Rosario Assunto.

In 1974, he presented the first global translation (by Peter Modesto) of the monumental work The Pillar and Ground of the Truth by the philosopher and mystic Russian Pavel Alexandrovich Florensky.

As a preface author and critic, Zolla wrote about Yakup Kadri Karaosmanoğlu, the Upanishads, The Imitation of Christ, Richard Rolle, Ioan Petru Culianu, Mircea Eliade, Thomas Mann, Marquis de Sade, Kafka, James Joyce, Emily Dickinson, Herman Melville (and oversaw a translation part of the poem Clarel), Nathaniel Hawthorne, Margery Kempe, F. Scott Fitzgerald, and other twentieth-century American writers.