In a letter to his wife, he wrote on 25th April 1937, "I who am not generally afraid in the face of danger, I am sometimes seized by a fear of death, without there being any particularly objective reason."
During the night of the 3rd and 4th May he wrote to his daughter Mane-Louise:
"What evil the Communists are doing here too! It is almost 2 o'clock and I am going to bed. The house is on its guard tonight. I offered to stay awake to let the others go to sleep, and everyone laughed, saying that I would not even hear the cannon! But afterwards, one by one, they fell asleep, and I am watchful over all of them, while working for those who are to come. It is the only completely beautiful thing. More absolute than love and truer than reality itself: What would humanity be without this sense of duty, without this emotion of feeling bound to those who were, who are distant, ignored, lost? Sometimes I think that this Messianic sense is no more than escapism, is no more than the search for and construction of an equilibrium, a stability which otherwise would precipitate us into disorder or despair. Whatever it is, it is certain that the most intense sentiments are the most human.
"One can lose one's illusions about everything and about everyone, but not about what one affirms with one's moral conscience. If it was possible for life to save Bilbao with my life, I should not hesitate for one instant. (...)
"All that I have said above has a slightly ridiculous solemnity for anyone who does not live here. But perhaps one day, if I can talk to you of these months, you will understand."