As many other thinkers of his time, he involved himself socially and politically: he was a Republican and fought the Miguel Primo de Rivera dictatorship (he was condemned to jail for a month) and showed his disagreement with Spanish communism.

But what is beyond discussion is that the prophecies from the extreme right-wing or monarchic sides that opposed to the Republic were completely fulfilled: non-stop chaos, strikes with no motivation, burnings of churches, religious prosecution, taking away the power from the liberals, who had sponsored the movement and who didn't fall into classes politics; refusal to admit in normality to right-wing people who obeyed the regime in good faith, although they logically weren't ignited with republican extremism.

Many centuries of success in the governing of the people (some not extinguished yet, as the English and American democracies) had given to the liberal person an excessive, sometimes conceited confidence in his superiority.

Whichever the political future of Spain may be, there is no doubt that in this stage of its history, it was the reactionary, and not the liberal, who got it right.From December 1936 to autumn of 1942, Marañón lived abroad, in a de facto exile.

After the student riots at the University of Madrid in 1956, he led, along with Menéndez Pidal, protests denouncing the dire political situation under Francoist rule, asking for the return of those exiled.

During his first year of graduate school (1909) he published seven works in the Clinical Magazine of Madrid, of which only one was related to endocrinology, about the autoimmune polyendocrine syndrome.

In his works he analysed, creating the unique and unprecedented genre of "biological essays", the great human passions through historical characters, and their psychic and physiopathologic features: shyness in his book Amiel, resentment in Tiberio, power in The Count-Duke of Olivares, intrigue and treason in politics in Antonio Pérez (one of the makers of the Spanish "black legend"), the "donjuanism" in Don Juan, etc.

What makes his work even more singular is the "human" perspective that summarizes the multiplicity of domains that he is involved in, partaking in the scientific, ethical, moral, religious, cultural, and historic.

Furthermore, "it is a cornerstone of the Foundation the localization and recuperation of all the biographic and bibliographic documents to constitute a Documentary Fund available to all the learners who want to analyse and go deeper into the signification and validity of the thinking and work of Gregorio Marañón".