Doubt: our greatest gift? Unamuno, Life 6.13

Unamuno explains that he finds doubt fundamental to the human condition. It is normal for us to doubt, no matter what we happen to believe, or how that belief finds expression in the activity of our life. To be without doubts, he thinks, is to be in some sense inhuman (monstruous, obscene, deformed).

La certeza absoluta, completa, de que la muerte es un completo y definitivo e irrevocable anonadamiento de la conciencia personal, una certeza de ello como estamos ciertos de que los tres ángulos de un triángulo valen dos rectos, o la certeza absoluta, completa, de que nuestra conciencia personal se prolonga más allá de la muerte en estas o las otras condiciones, haciendo sobre todo entrar en ello la extraña y adventicia añadidura del premio o del castigo eternos, ambas certezas nos harían igualmente imposible la vida. En un escondrijo, el más recóndito del espíritu, sin saberlo acaso el mismo que cree estar convencido de que con la muerte acaba para siempre su conciencia personal, su memoria, en aquel escondrijo le queda una sombra, una vaga sombra, una sombra de sombra de incertidumbre, y mientras él se dice: «ea, ¡a vivir esta vida pasajera, que no hay otra!», el silencio de aquel escondrijo le dice: «¡quién sabe!...» Cree acaso no oirlo, pero lo oye. Y en un repliegue también del alma del creyente que guarde más fe en la vida futura hay una voz tapada, voz de incertidumbre, que le cuchichea al oído, espiritual: «¡quién sabe!...» Son estas voces acaso como el zumbar de un mosquito cuando el vendaval brama entre los árboles del bosque; no nos damos cuenta de ese zumbido y, sin embargo, junto con el fragor de la tormenta, nos llega al oído. ¿Cómo podríamos vivir, si no, sin esa incertidumbre?

El «¿y si hay?» y el «¿y si no hay?» son las bases de nuestra vida íntima. Acaso haya racionalista que nunca haya vacilado en su convicción de la mortalidad del alma, y vitalista que no haya vacilado en su fe en la inmortalidad; pero eso sólo querrá decir a lo sumo que así como hay monstruos, hay también estúpidos afectivos o de sentimiento, por mucha inteligencia que tengan, y estúpidos intelectuales, por mucha que su virtud sea. Mas en lo normal no puedo creer a los que me aseguren que nunca, ni en un parpadeo el más fugaz, ni en las horas de mayor soledad y tribulación, se les ha aflorado a la conciencia ese rumor de la incertidumbre. No comprendo a los hombres que me dicen que nunca les atormentó la perspectiva del allende la muerte, ni el anonadamiento propio les inquieta; y por mi parte no quiero poner paz entre mi corazón y mi cabeza, entre mi fe y mi razón; quiero más bien que se peleen entre sí.

Absolute certainties would make our lives impossible. Imagine for a moment that we are utterly certain, with no room at all for doubt, that death represents a total, definitive, and irrevocable annihilation of personal consciousness—and we know this as surely as we know that the sum of three angles in a triangle is the same as the sum of two right angles. Now, imagine us similarly sure that our personal conscience endures beyond death, in conditions like these or in some other conditions, with the strange and unusual addition of eternal reward and punishment. In either case, life as we know it becomes impossible. Without even being aware of it himself, the man thoroughly convinced of his own mortality keeps a vague shadow of a doubt buried deep in his mind, in the farthest hidden corner of his consciousness. While he says to himself, “Go to then! Live this fleeting life, for there is no other!” this hidden shadow of a shadow mutters a very different tale in the silence of his mind: “Who knows?” The man might think he doesn't hear it, but he does. We find a very similar situation in the soul of the most fervent believer, the one with most faith in a future life. Here too is a quiet voice, a voice of doubt cutting at his spiritual ears: “Who knows?” These voices may be likened to the buzz of a mosquito in the midst of a windstorm wreaking havoc among the trees of the forest. We don't hear the buzz distinctly in the midst of the crashing storm, but still it reaches our ears somehow. How could things be different, really? How could we live without this anchor of uncertainty?

At the foundation of our most private life lie questions: “Is there more? Is this it?” Perhaps there exists somewhere a rationalist who has never wavered in his conviction of the soul's mortality, and a vitalist whose faith in immortality has never faltered. This will amount to nothing more than a recognition of extreme aberrations: as there exist people with shocking physical deformities, so there are outliers among us with very deformed minds. Some are emotional idiots, in spite of all the rational intelligence they possess, and others are rational dolts, for all that they have great emotional virtue. But in the normal shape of things, I cannot believe those who assure me that they have never been reached by the rumor of doubt—that its flower has never bloomed in their minds, not even for the briefest of moments, when they were most lonely and afflicted. I do not understand men who tell me that the prospect of the afterlife never tormented them, or that they never shuddered to contemplate their own annihilation. For my own part, I do not wish to impose peace on my heart and my head, on my faith and my reason. I prefer that they fight each other without stint.