Still under the impact of his recent orphan condition, the young Delfim kept the family business running for a while, only to become aware that his vocation and motivation lay elsewhere and thereby decided to pursue a lifelong engagement with study and intellectual quest.

Meanwhile, Delfim received his PhD in 1940 from Coimbra University presenting a thesis on Knowledge and Reality (Conhecimento e Realidade), and returned to Berlin where he was to remain until 1942, the year in which he permanently resettled in Portugal.

He was member of the Lisbon Academy of Sciences and exchanged personal correspondence with international scholars and writers such as Mircea Eliade, Constantin Noica, Hermann Hesse, Ernesto Grassi and Michael de Ferdinandy.

His main books are: Aware of the cinema educational and formative potential, he wrote a number of movie reviews, namely on The Prodigal Son (Luis Trenker, Germany 1934), The Third Man (Carol Reed, USA 1949) and Umberto D. (Vittorio de Sica, Italy 1952).

Also from Hartmann's 'levels of reality' he adapted and further developed his own pluriversal or rather pluriregional views on 'reality', ascribing the scientific method of study exclusively to the material world and not to philosophical matters as the neopositivists propounded.

Delfim made extensive public proposals towards a complete reform of the Portuguese educational system from kindergarten to university, showing a strong concern for professional instruction and apprenticeship; he recommended characterology as an auxiliary to vocational guidance and published several essays on foreign pedagogues, namely on Johann Heinrich Pestalozzi and Maria Montessori, making also pioneering research on some of the most prominent Portuguese educationalists, notably Almeida Garrett (1799–1854) and Adolfo Coelho (1847–1919).