I read this in translation (the Spanish original title is different) many
years ago, but it jumped out at me again after reading the following from
Misak's Cambridge Pragmatism:
"James was the opposite of Peirce - charming, personable, and an accessible
writer. But he ignited the philosophical rage of the hard-headed realists
Russell and Moore by seeming to suggest in his 'The Will to Believe' and
'The Sentiment of Rationality' that if the hypothesis of God's existence
makes one's life more bearable, then that is a kind of evidence that God
exists. . . He goes on to maintain that if the effects of believing in the
hypothesis of God's existence are good for the individual, then she should
believe. . . ."
Unamuno's Father Bueno was an exemplary priest, ascetic, kind, admirably
caring for others. At the end of the short story he informs someone that he
knows God doesn't exist, but that it is important to pretend that He does
for the well-being of his flock. I wondered after reading the above whether
Unamuno was familiar with William James.