Giuseppe Rensi was an Italian skeptical philosopher and professor of philosophy at the universities of Messina and Genoa. Rensi first upheld a religiously or theistically oriented idealistic philosophy, defending it in a number of essays and fostering it through his translations of the works of Josiah Royce. He contrasted his theistic "constructive idealism" with the "immanentistic idealism" of Benedetto Croce and Giovanni Gentile; he regarded the latter as a temporary position that, if developed coherently, would have led to constructive idealism. According to Rensi, an idealism that does not arrive at God subtracts reality both from the external world, which then becomes a set of ideas, and from the human spirit, which is then resolved into a set of ideas without a subject.

After World War I, regarded by Rensi as proof of the fundamental irrationality of the world, he began to defend a...